HomeMy WebLinkAbout2005-04-05; City Council; 18062; Presentation Rancho Carlsbad Owners' AssociationCITY OF CARLSBAD -AGENDA BILL - TITLE:
REQUEST TO MAKE A PRESENTATION FROM RANCHO
CAKLSBAD OWNERS’ ASSOCIATION
AB# 18,062
MTG. 415105
DEPT: CM
DEPT. HD.
CITY Any. &
CITY MGR
RECOMMENDED ACTION:
Receive presentation from the Rancho Carlsbad Owners’ Association.
ITEM EXPLANATION:
The City Council provides an opportunity for citizens and organizations to have an item
placed on a City Council Agenda by submitting a letter to the City Manager. Attached is a
letter (Exhibit I) from Bill Arnold, President, Rancho Carlsbad Owners’ Association,
requesting the opportunity to make a presentation to the City Council regarding the City of
Carlsbad flood control program for the Rancho Carlsbad Area.
FISCAL IMPACT:
Unknown at this time
EXHIBITS:
I.
Owners’ Association, dated March 1 st, 2005.
Letter to Ray Patchett, City Manager, from Bill Arnold, President, Rancho Carlsbad
a
J+n;1- Ed &- Owners’ Association, Inc. &-eK@-
5200 El Camino Real, Carlsbad, California 92008
Phone: (760) 438-0333 Fax: (760) 438-1 808
March 1,2005
Mr. Raymond R. Patchett, City Manager
City Of Carlsbad
1200 Carlsbad Village Drive
Carlsbad, CA 92008
Dear Mr. Patchett:
On behalf of our Owners’ Association, I am requesting that we be placed on the agenda at the
next scheduled meeting of City Council, March 15,2005.
The purpose for this request is to allow our Association to address the full Council in open forum
of our hstration in getting city government to give priority attention and timely implementation
of the city’s flood control program for Rancho Carlsbad. We are fully cognizant of the many
outside governmental agencies hurdles that this plan must overcome. What I am speaking about,
are those sections of the plan that are within the control of the City and the inordinate time it
takes to get things accomplished.
City Council needs to be made aware of our concerns, set priorities and remove us as promptly as
possible from the devastating effects of a major flood. This years excessive rainfall has re-
awaken us to this flooding potential. Fortunately, mother nature has been kind to us, so far, but
in several of these storms an hour’s more of heavy rain would have caused the creeks flowing
through our community to breach and threaten the property and lives of our residents.
In the City Council’s values statement you make reference to providing a “safe community”,
“top quality service”, and “timely response”. The City has an obligation to protect the citizens
of its community and in our view, it is failing to meet that obligation.
Thank you.
President I
z&f& &e Owners’ Association, Inc.
5200 El Camino Real, Carlsbad, California 92008
Phone: (760) 438-0333 Fax: (760) 438-1 808
AGhiWA ITEM # 24
C: Mayor
Rea q-Lt-05
CCW. eler\(
=-* eie+ April 1,2005 I-+%*‘ c Yt, e\* City Council
City Manager
City Attorney
City Clerk
To: Carlsbad City Council
1200 Carlsbad Village Drive
Carlsbad, Ca. 92008
Listing of reference enclosures to support our concerns re: early completion of our flood
mitigation plan.
1 - City ordinance No. NS-392, dated 112 1/1997 approving Rancho Carlsbad for condominium
ownership, include OUT site into the master drainage plan, and assessing us $3 18,000 for our
share of the mitigation cost.
2- Rick Engineering report entitled “Rancho Carlsbad Channel & Basin Project” dated 6/30/98.
3- Letter 3/18/99 from our Attorney to City Staff asking questions about implementation of the
flood mitigation plan of 6/30/98. No response could be located
4- Letter fiom the City dated 2/2/2000 advising us of an Environmental Impact Report in process
that will involve construction of two detention basins (part of our flood mitigation plan).
5- Letter fkom the City dated 5/30/2000 answering questions our attorney raised regarding this
same E.I.R. which also involves extensions of Cannon Road, and College Blvd. in our immediate
area.
6- RCOA internal memo following a meeting with Deputy City Engineer David Hauser.
7- RCOA letter dated 8/29/2001 to David Hauser referencing the excessive silting of our creeks
and requesting early action.
8- RCOA in house memo dated 10/2/2001 indicating City Staff and a consultant were inspecting
our stream beds.
9- City of Carlsbad Agenda Bill dated 3/5/2002 approving a consultant agreement to do
environmental and engineering work for our channel project.
10- City letters (3) dated 8/6/2002 requesting permits fkom Governmental Agencies to begin
dredging. RCOA wrote follow up letters dated 5/27/2002 to these same Agencies.
11- Rick Engineering report dated 1/8/2003 entitled R.C. M.H.P preliminary alternatives analysis
for Agua Hedionda. This report indicated a much worse flooding problem since the 6/30/98
report by the same firm.
12-RCOA letter dated 3/20/2003 to David Hauser urging prompt action on our total flood
mitigation plan in view of the new information.
13- RCOA letter dated 5/12/2003 to City Manager, Ray Patchett as a follow up to our 3/20/2003
letter again urging prompt action since we had not received any response.
14- City letter dated 7/11/2003 fiom David Hauser responding to our 3/20/2003 letter.
15- City letter dated 4/13/2004 outlining a timetable for full completion of our flooding problem.
16- Rick Engineering report dated 12/13/2004. This report is the final product of a review of
technical data begun in July 2003 concerning our flooding potential.
17- E-Mail form David Hauser dated 1/11/2005 in answer to ours on the flood issue.
18- Meeting minutes dated 2/1/2005 of City discussion of Rick Engineering report.
19- Internal City memo dated 2/7/2005 on Rancho Carlsbad flood projects particularly
installation of the “84” storm drain pipe in Cannon Road.
20- City letter dated 2/11/2005 from Mayor Lewis answering our request that the City take the
lead in installing the “84” drain pipe.
2 1 - RCOA letter dated 2/22/2005 inquiring about progress on dredging permits.
22- RCOA letter dated 2/22/2005 in reply to Mayor Lewis’s letter detailing a series of concerns
should the “pipe” installation be tied into McMillin’s Robertson Ranch Plans.
23- Copy of RCOA Courtesy Patrol log for the early morning hours of February 23, 2005,
another night of heavy rain. That was the night a City Police car hit a power pole on El Camino
Real. Note: The employee’s comment “Power went out in park.”
24-RCOA letter to City Manager requesting a hearing before City Council.
25- Memo fiom local Real Estate Office plus copy of letter dated 6/25/2004 U.S. Department of
Housing and Urban Development turning Rancho Carlsbad down for reverse mortgage
certification.
26- E-Mail from Bob Ladwig, our consultant pointing out that in all these flood studies our
North wall was always considered a “flood wall” which it never was. Hence our flood situation
is worse than reported.
Also included are selected photo’s since 1/9/2005 highlighting the water flow height and related
damage.
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ORD;MANCENO. NS-392
AN ORDMANCE OF THE CITY COUNCIL OF THE CITY OF
CARLSBAD, CALIFORNIA, Ah/lENbMG TITLE 21,
CHAPTER 21.05, SECTION 21.05.030 OF THE CARLSBAD
MUNlClPAL CODE BY AN AMENDiME" TO TE ZONrEtO
TO WEST RV THIS AFtM) AT RANCHO CARLSBAD DRIVE, IN LOCAL FACILITIES MANAGEMENT ZONE 15. 'e& CASE NAME: RANCHO CARLSBAD MOBILEHOME.
PARK
'".e p -
CASE NO .. * ZC 96-04 -
The City Council of the City of Carlsbad, California, docs ordain as follows:
SECTION I: That Title 21, Chapter 21 .OS. Section 21.05.030 of fhs Wlsbad
Municipal Code, being the Zoning Map, is amended to reflect a mnt change from L-C to RMHp
as shown on that portion of the map marked ''Exhibit ZC 96-04", attached hereto and made a part
henof by this reference.
SECTIONII: That the findings of the Planning Commission as set forth in
Planning Commission Resolution No, 403 1 constitutes the findings of the City Council.
SECIYdN Ut: The, Council further finds that this action is consistent with the
Land Use Element and the Housing Element of the Carlsbad General Plan. 1
EFFECTIVE DATE: This ordinance shall be effective thirty days after irs
Idoption, and the City Clerk shdl certify to the edoption of this ordinance and cause it to bc
published at least once in a newspaper of general circulation wit'hin fifteen clays after its
adoption.
NTRODUCED AND FIRST READ at a .regular niectiny of the Carlsbad City
Council held on t5t 21nt day of January 1997. and thcrtaflcr . '
I. .!
A
W C I hl'llnTCYU ifuuClwHCI
"0: 97-44
A RESOLUTION OF THE CITY COUNCIL OF THE GIN OF
CARLSBAD, CALIFORNIA, APPROVING A ZONE CHANGE
(FROM L-C Tr3 RMHP ZONING), RESfDENTlAL MOBILEHOME
PARK PERMIT, AND TENTATIVE PARCEL MAP TO CONVERT
AN EXISTING 108.4 ACRE, 504 SPACE MOBILEHOME PARK
FROM A RENTAL PARK TO CONDOMINIUM OWNERSHIP ON
PROPERR GENERALLY L~A f tu ON T HE NORTH SI& OF EL CAMINO REAL (WHICH RUNS EAST TO WEST IN THIS
AREA) AT RANCHO CARLSBAD DRIVE IN LOCAL FACILITIES
MANAGEMENT ZONE 15.
CASE NAME: RANCHO CARLSBAD MOBfLEHOME PARK
* CASE NO. RMHP 96-911MS 96-08
WHEREAS, Carlsbad Resident Association, hCl, "DWeloper". has filed a
verified applicatfm with the City of Carlsbad regarding property ownsd by Cailsbad
Resident Association, Inc., Carlsberg Rancho, LTD, Brookdale Terrace Buiirfha
Company, and Oak S hado;vs Building Company 'Owner", described as
A portion of Lot "B" and Lot "E" of Rancho Agua
Hedionda, in the City of Cadsbad.'County of San
Diego, State af.Califomia, per map thereof No. 823,
filed in the offica.of the County Recorder of said county,
November 16, 1896.
?the Property"); and
WHEREAS, on December 18, 2996. the Carlsbad Planning Covmlssion
ield a duly noticed public hearing to consider a ResideRtial Mobilehome Park Permit
RMHP 96-01) and Tentative Parcel Map (MS 96-08) to convert Rancho Carlsbad
wlobilehome Park from a rental park.to condoniigiurn ownership and adopted Planning li 25 I li Commission Resolutions No. 4032 and 4033 i-espectively, recommending tc the City
26 1 Council that they be approved; and 27 1
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WHEREAS, the City Council of the City of Carlsbad, held a public hearing
on January 21, 1997 to consider the recommendations and heard all persons interested
in or opposed to ZC 96-04RMHP 96-01/MS 96-08; and
WHEREAS, fk findings and conditions of Planning Commission
Resolution Nos, 4032 and 4033 recommending approval Of the Residential Mobilehome
Park Permit and Tentative Parcel Map constitute the findings and conditions of the City
Council;
WHEREAS, the Planning Director issued 8 Notice Of Exemption dated
November 21, 1996 for this project pursuant to California Public Resources Code
sections 1506l(b)(3) and 21080.8,
NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of
Carlsbad, California, as follows:
1. That the above recitations are true and correct.
2. That .Residential Mobilehome Park Perrnlt (RMHP 96-01) for this project
is approved and that the ff ndings and conditions of the Planning Commission contained in
Resolution No. 4032, on file'with the City Clerk and incorporated herein by reference, are
the findings and conditions of the City Council.
3. That the approval of Tentative Parcel Map (MS 96-08) is approved and
that the findings and conditions of the Planning Commission contained in Planning
Cornmission Resolution No. 4033, on file with the.City Clerk and incorporated herein by
reference, are the findings and conditions of the City Council with the following
amendments:
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A. Finding No. 11 is amended to read as follows:
"I?. That Improvements proposed in the Master Drain8 e - Plan will reduce flooding impacts and improve drainage to the mobilehome --T-mi& par of the Rancho Carlsbad Mobilehome Park are located within the 100 year floodplain 8s
identified by the Federal Emergency Management Act (FEW). AS provided in the
Subdivision Map Act, the City is authorized to reqlrlre afly improvements necessary to
mitigate existing health and safety conditions. Because health and safety condition's exist
(flooding), mitigation of the flooding impacts has been required as a condition of project
approval. To facilitate the mitigation of flooding impacts, the City has agreed to include
the site into the Master Dralnage Plan and the applicants have agreed to the contribution
of monies estimated to be $318,000 over a ten and one-half year period. In addition, the applicant has agreed- to provide easement dedications for take Calavera Creek and Agua
Hedionda Creek drainage channels to permit the City to mitigate flooding and drainage
impacts pursuant to the Master Drainage - Plan. These improvements will benefit the owners of the mobilehome park by reducing flooding impacts and improving drainage to
the park."
B.. Conditions No, 10 and 16d. are amended to read as follows:
"IO, The applicant shall enter into a SeCUred agreement with
the City to conthbute $318,000 plus interest fixed at 6% per year for the first 18 months,
and thereafter interest adjusting to equal the City's annual return On its portfolio each
December as determined by the City Treasurer In ten installments with the first installment due 18 monfhs after the date of recordation of the final parcel map. The agreement shall
be approved by the City Attorney and may be executed by the Chy Manager. The
remaining principal and interest shall be paid annually thereafier and the entire principal
and interest shall be paid OH within ten years and six monfhs of recordation of the final
Darcel map or sooner at the election of the applicant."
"l6d. The owner of this property on behalf of itself and all of
ts successors In interest has agreed to hold harmless and indemnify the City of Carlsbad
rom any action that may arise through any damages caused by the developer-owned on-
;ite drainage system." '
. C. Condition No. I1 is deleted.
4. This action is final the date this resolution is adopted by the City Council.
'he provision of Chapter 1.76 of the Carlsbad Municipal Code, "Time Limits for Judicial
Eeview" shall apply:
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"hldTiCE TO APPLICANT"
"The time within which judicial review of this decisfon
must be sought is governed by Code of Civil Procedure, Section
1094.6, which has been made applicable in the City of Carlsbad by
Carlsbad Municipal Code Chapter 1.16. Any petition or other paper seeking judicial review must be filed in the appropriate coutl not later
than the ninetieth day following the date an which this declsion becomes final; however, if within ten days after the decision
becomes final a request for the record of the proceedings
accompanied by the required deposit in an amount sufficient to cover the estimated cost of preparation of such record, the time within
which slrch petition may be filed in court is extended to not later than the thirtieth day following the date on which the record is either
. personally delivered or mailed to the paw, or his attorney of record,
if he has one A written request far the preparation of the record of
the proceedings shall be filed with the City Clerk, Cit>t of Carlsbad,
1200 Carlsbad Village Drive, Carkbad, California 92008."
PASSED, APPROVED AND ADOPTED at a Regular Meeting of the City
COunCif of the City of Carlsbad on the 28th day of January 1Q97, by the
'fallowing vote, to wit:
AYES: Council Members Lewis, Flnnila, Nggaard, KulcSfn and. Hall
NOES; Kent
ABSENT: ??**e
h Jz2L 1LETHA L. fWbTENKRAN2, City Cle
:SEAL)
4
V SlN3CIIS3d aV'8SlW3
AB# /ydO?
MTt3.f 'ai. 93
DEPT. PLN @
RECOMMENDED ACTION:
m: DEPT. d.
RANCHO CARLSBAD MOBILEHOME PARK CITY ATTY. sd?-
CITY MGR2.1 I Y ZC 9S-OIIRMHP 96-011MS 96-08
That the City Council ADOPT City Council Resolution No. 9?-db APPROVING RMHp
96-01 and MS 96-08 as recommended for approval by the Planning Commission artd
iNTRODUCE Ordinance No. ,V5- 392-
17EM EXPLANATION:
APPROVING ZC 96-04. 1-
On'Decembet 18, 1996, the Planning .Commission conducted a public hearing to review the Rancho Carisbad Mobilehome Park project located on the north side of El Camino Real 'which runs east to west in this area) at Rancho Carlsbad Drive, in Local Facjljties Uanagement Zone 15. The Planning Commission recommended approval (4-0) of ZC &:
14, RMHP 06-01, and PAS 96-08. Approxfmately eight residents Of the-Rancho Carlsbad
dobilehome park provided public testimony in favor of the pr5ppSed mobilehanle park
:onversion, and approximately sixty residents were in attendance at the meeting. I The discrettlonary actions to be decided by the City Council include a zone Change from L-
C to RMHP'Zoning, a Residential Mobilehome Park Permft, and Tentative Parcel Map to
convert the existing. 108.4 acre mobilehome park from a rental park to a resident-owned,
I condominium mobilehome park. The park contalns 504. existing spaces, two recreation
areas and a recreation vehicle storage facility, A small portion of the property occupied by
coaches and the lot containing RV storage and recreational facilities, is proposed to be
rezoned from its current Limlted Control (L-C) Zoning to Residential Mobilehome Park
(RMHP) Zoning consistent with the existing uses. The project does not comply with all of
the development standards of the RMHP Zone. However, provisions for waiver 0: development standards of Chapter 21.37 of the Municipal Code are included in the RMHp Zone, and the Planning Cornmission has recommended approval of such waiver. The
mobilehome park is also subject to the development standards of the California Code of
Regulations. Title 25, Division 1 , Chapter 2, Mobilehome Park Act (Title 25). Development
standards of Title 25 may not be waived, therefore, as caoditioned, the project shall comply
with all T#le 25 regulations. These will be verified through the City's official Title 25 inspection process scheduled to begin in early 1907.
The Tentative Parcel Map is accompanying the RMHP and Zone Change as a package for Zouncil consideration, If approved by Council, the applicant will process a Parcel Map t3
'inalize the project. Pursuant to Chapter 20.24.iOO of the Municipal Code, the City fngineer has the authority to approve the Parcel Map anti record the final document with
he County Recorder.
Review of the proposed conversion included analysis of potential flood impacts since
portions of the park are located within the 100-year Roodplain as identified by the Federal
Emergency Management Act (f EMA). The studies. subrnltted by the applicant identified
s f
PAGE 2 OF AGENDA BILL NO. I Y;’ 00 5%
.I* flooding during the estimated 50 year storm P11r-m Act, the City
is avthorited to require only those immovemenb4xh ’ are necessary to mitigate existing’ heakh and safety concerns. Because the park is within the ldO-year floodplain, and
because the reports substantiate that a health and safety condition exists, staff has required
mitimon of potential flooding impacts.
The applicants have agreed to the dedicafions of Lake Calavera Creek, Agua Hedionda Week and College Boulevard However, the applicants have noted that this agreement is subject to the subordination of the lender, General Electric Capital Corporation (GECC).
Parcel Map approval is subject to the dedication of these easements.
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The applicants raked several issues at the Planning Commission hearing. The primary
issues raised are summarized below.
e 1. . Payment of Public Facilities Fees - The applicants have contested the payment of
any Public Facilities Fees for future development of the Rancho Carlsbad X
Mobilehome Park.
2. Corn pfiance with Thte 25 - The applicants object to conditions 20 and 21 of Planning
Commission Resolution No, 4032 reqlairihg compliance with Title 25 development regulations .
loodina as a Health and Safety Issuc; - The applicants disagree that flooding at the
iobilehorne park is a health and safety issue and have reserved all legal rights
based upon the flood issue. In addition, the applicants have objected to Conditlon
#9, Resolution No. 4033, requiring the execution of a hold harmless agreement
regarding drainage; they have agreed to only a ten (-lo) year indernniflcatlon for damage due to flooding. Nonetheless, the applicants have agreed to contribute
monies, estimated to be $318,000 over a ten year period, to pay for flood mffigation
forthe mobilehome park.
3.
* ?
$i
Y &
ENVIRONMENTAL REVIEW:
The proposed conversion of a rental mobllehorne park to condominium ownership will not result in an expansion of, nor change in the existing me of the mobllehortle park. The
Planning Director has determined that the zone change is exempt from envlrbnrnentai
review pursuant to Section 15061(b)(3) of the California Public Resource Code (CEQA, and that the Residential Mobilehome Fark Permit and Tentative Parcel Map are exempt from
environmental review pursuant to Section 21080.8 of the California Public Resource C&e
(CEQA), which exempts mobllehorne park conversions from the requirements of CEQA. The Planning Director issued a Notice of Exemption dated November 21, 1996, for this
project.
FISCAL IMPACT:
No fiscal impacts will result from this existing mobilehame park. The project is located within the Zone 15 Local Facilities Management Plan. All facilities to service the
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PAGE 3 OF AGENDA BILL NO, J L/.i .. no 5
mobllehome park as It currently exists are currently available, and the conversion of the
mobilehome park to condominium ownership will not jeopardize the City's abibty to pravide necessary facilities and services to Zone 15.
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EXHl BITS:
I. City Council Resolution No. 9 9 - 2c;! ,
2. Ordinance No; tusa 5% (ZC 96-04) 3. Location Map
4.
5. 8.
7.
Jx Planning Commission Resolutions No. 4031,4032 and 4033
Planning Cornmission Staff Report dated December 18, 1896
Excerpts of Planning Commission Minutes dated December 18, 1996
1. Sue Loftin Letter, dated December 18,1998
' 8. Rancho CarIsbad letter, dated December 18, 1996
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,.< PASSED AND ADoPTED at a regular meeting of said city Council held on thc
- 28th day of Jarwary , 1997, by the following vote, to wit:
AYES: Council Xembers Lewis, FinnLla, Nygaard, Kulchin md Ball
NOES: None
ABSENT: Nons
ABSTAIN: None
APPROVED AS TO FORM AND LEOALITY
L.Q. h
8
ATTEST:
a ~ETHA L. RAUTENWNZ, City GiTI
(SEAL)
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‘‘EXHBIT ZC 96-04‘‘ /
RANCHO CARLSBAD
MOBILE HOME PARK
ZC 96-04
A
RANCHO CARLSBAD CHANNEL & BASIN PROJECT
(Job Number 13 182)
June 30, 1998
Prepared for:
City of Carlsbad
2075 Las Palmas Drive
Carlsbad, California 92009- 1576
R.C.E. #32838
Exp. 6/02
Prepared By: Cf/P/e-lr 73
n, uj,c. 1(
g1/7t2- 1. Water Resources Division 3aM 5 5620 Friars Road
Rick Engineering Company
San Diego, California 92 1 10-2596 RECE I VED (6 19) 29 1-0707 pAh& Fy
b,rciG Ir 3 'is?@
io LAOWIG CESIZN GR
vr
TABLE OF CONTENTS
Introduction .........&.. .................................................. 1
................................................... Hydrologic Methodology 1
Vicinity Map ............................................................ 2
Hydrologic Results ........................................................ 5
Hydraulics .............................................................. 13
.Maintenance Plan ............................................................... 14
Environmental Issues ...................................................... 16
ProbableCosts ........................................................... 20
Recommendations ........................................................ 21
References .............................................................. 23
Tables
1. Comparison of 1 00-year, 24-hour Peak Flow Discharges
with Existing Detention Facilities and with Both Existing
and Proposed Detention Facilities, Ultimate. Development,
Rancho Carlsbad Mobile Home Park ....................... ......... ... 7
2. Summary of Proposed Detention Facilities, Rancho Carlsbad Channel
and Basin Project, 100-year, 24-hour Storm Event ............................ 12
3. Rancho Carlsbad Detention Basins - Direct Impacts (Acres) .................... 17
4. Rancho Carlsbad Detention Basins - Mitigation Requirements (Acres) ............ 18
5. Rancho Carlsbad Detention Basins - Potential Indirect Impacts (Acres) ........... 19
6. Opinion of Probable Costs for Rancho Carlsbad Channel & Basin Project ......... 20
Prepared By: DCB:MDL:ernn/Report/J-l3 182.00 I
Rick Engineering Company - Water Resources Division 070 1 /98
- , '. .. I *.
ADD en dices
1, 100-year, 24-hour mC-1 Analysis for Rancho Carlsbad Mobile Home Park Ultimate
Development with Existing Detention Basins (File Name: rcmh24r.hcl)
2. 100-year, 24-hour HEC-1 Analysis for Rancho Carlsbad Mobile Home Park Ultimate
Development with Existing and Proposed Detention Basks (File Name: rccbpr.hc1)
3. 100-year Floodplain HEC-2 Analysis for Rancho Carlsbad Mobile Home Park (File Name:
FEW5 . hc2)
lWaD Pockets
1. Effective FIRM
2. Watershed Boundary Map
3. Conceptual Plans for the Proposed Melrose Drive Detention Facility
4. Conceptual Plans for the Proposed Faraday Avenue Detention Facility
5. Conceptual Plans for the Proposed BJB Detention Facility
6. Conceptual Plans for the Proposed BJ Detention Facility
7. 1 00-year Floodplain Map of Rancho Carlsbad Mobile Home Park
Prepared By DCB.MDL'ernnlReportlJ-I 3 182.001
Rick Engineering Company - Water Resources Division 0710 1/98 !* ,-, .
Introduction
This report has been prepared to summarize the hydrologic and hydraulic studies conducted
by Rick Engineering Company for the City of Carlsbad as part of the Rancho Carlsbad Channel and
Basin Project. Rancho Carlsbad Mobile Home Park (RCMHP) is located north of El Camino Real
midway between College Boulevard and Tamarack Avenue. See the Vicinity Map on the next page.
RCMHP contains portions of both Agua Hedionda and Calaveras Creeks. Agua Hedionda Creek
flows westerly through the southern portion of RCM". Calaveras Creek flows southwesterly along
the northern property boundary. Calaveras Creek confluences with Agua Hedionda Creek within
RCMHP approximately 300 feet upstream of El Carnino Real. The Federal Emergency Management
Agency (FEMA) Flood Insurance Rate Map (FIRM) shows that a large portion of RCMHP is
inundated by the 100-year storm. See the FIRM in Map Pocket 1. The purpose of this study is to
provide recommendations for minimizing the 100-year flooding in RCMHP. These
recommendations include upstream detention basins to decrease the peak flow and on-site creek
improvements to increase the creek capacities.
Hydrologic Methodology
Hydrologic analyses were prepared to determine the 1 00-year peak discharge within RCMI-P
and to analyze proposed detention scenarios. Two hydrologic analyses using the U. S. Army Corps
of Engineers' HEC-1 flood hydrograph program are included in this report. The first analysis
modeled the existing detention facilities and ultimate development. Ultimate development was
assumed in order to account for the maximum anticipated discharge in the watershed. The results
of the first analysis confirmed that the creeks in RCMHP are inadequate to convey the 100-year
DCB:MDL:ernn/Report/J-13 182.001 1 07/0 1/98
Prepared By:
Rick Engineering Company - Water Resources Division
VICINITY MAP
RANCHO CARLSBAD MOBILE HOME PARK
CITY OF OCEANSIDE
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stom. Therefore? additional analyses were performed in order to study detention scenarios. The
HEC-1 analysis contahing the most desirable detention scenario is included in this report and is
based on the existing and four proposed detention facilities and ultimate development within the
entire watershed. The HEC-1 input and methodology are discussed below. The HEC-1 results are
discussed in the following section.
Prior to preparing the HEC-1 input, previous studies (listed in “References”) for RCMHP
were reviewed and site visits were performed. The site visit objectives were to verify the watershed
boundary and major flow paths of both Agua Hedionda and Calaveras Creeks, determine existing
detention locations, and review proposed detention locations. Prior to the site ,visits, the watershed
boundary and flow paths were delineated on the United States Geological Survey’s (LJSGS)
quadrangle maps. The watershed was divided into sub-basins in order to obtain peak flows at
existing and proposed detention facility locations and at locations listed in the current Flood
Insurance. Study. The watershed boundary, flow paths, and sub-basin boundaries were verified
during the site visits and adjusted appropriately. See Map Pocket 2 for the RCM” watershed
boundary map.
A
During the site visits, existing detention facilities such as dams and road embankments were
noted. Two dams exist within the RCMHP watershed: Calaveras and Squires. Of these two, only
Calaveras dam provides significant detention. It is located within Calaveras Creek and detains the
upstream creek flows. On the other hand, Squires Dam is located at the upper end of a drainage
basin and provides minimal detention. The plans for Calaveras Dam were obtained fiom the
Division of Safety of Dams @SOD) and the outlet works and storage capacity were modeled in the
hydrologic analyses.
DCB:MDL:emn/RcpodJ-13 182.001 3 07/0 1/98
Prepared By:
Rick Engineering Company - Water Resources Division
Furthermore, the following road embankments were identified as potential existing detention
facilities: Business Ptirk Drive (south of Park Center Drive), Sycamore Avenue (north of Grand
Avenue), Shadowridge Drive (north of Antiqua Drive), Melrose Drive (north of Cannon Road), and
Melrose Drive (south of Aspen Way). As-built plans for these road crossings were obtained from
the appropriate agencies. The culverts and storage capacities of the Sycamore Avenue, Shadowridge
Drive, and Melrose Drive (Cannon Road) facilities were modeled in the hydrologic analyses. The
Business Park Drive and Melrose Drive (Aspen ,Way) crossings were not modeled because the
culverts at these locations are large enough to convey most of the upstream flows with minimal
detention.
Two main criteria were considered in selecting potential proposed detention basin sites.
I First, the facilities listed in the Master Drainage Plan were considered. Second, existing or proposed
I road crossings were considered. Detention basin construction at road crossings provides several
benefits. Road crossings create a natural location for detention. They are cost-effective because the
road embankment is used for detention. They do not create a significant increase in environmental
impacts.
The above-mentioned sub-basins and detention facilities were modeled in the HEC-1
program. The program parameters include sub-basin area, rainfall distribution, lag time, and curve
number. These parameters were determined as follows: The sub-basin area was obtained from the
USGS watershed boundary map. The rainfall distribution was based on storrn duration and
frequency, as well as the sub-basin’s geographic location. The lag time was based on sub-basin
characteristics such as topography, basin shape, vegetative cover, existing development, and storm
duration. Both rainfall distribution and lag time were generated by utilizing the criteria outlined in
DCB:MDL:crnnlRcportlJ- 13 182.00 1
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the County of San Diego Hydrology Manual. Curve numbers are a function of land use and soil
type. The land use cherages were obtained from the City of Carlsbad’s Geographic Information
System (GIs). The land use was revised slightly in three locations according to a December 12, 1997
exhibit from the City of Carlsbad. In open space areas, land use was based on vegetative cover
estimates obtained from the Soil Conservation Service’s (SCS) Sun Diego Counv Soil Interpretation
Study Ground Cover maps, as well as field observations. The soil type coverages are delineated on
the SCS’s Soil Survey maps. These coverages were obtained from the San Diego Association of
Governments (SANDAG) in digital format. Once the land use and soil types were established, the
curve numbers were then calculated using the method outlined in the San Diego County Hydrology
Manual.
The curve number, lag time, rainfall distribution, and area for each sub-basin were generated
and input into the HEC-1 program. The HEC-1 program then computed the runoff hydrograph and
peak discharge for each sub-basin. The existing detention facilities were modeled in the first HEC-1
analysis, while both existing and proposed detention facilities were modeled in the second HEC-1
analysis.
Hydrologic Results
The results of the two aforementioned HEC-1 analyses for RCMHP are discussed below.
For the first HEC-1 analysis, which modeled the existing detention facilities and ultimate
development, both six- and 24-hourY 100-year storms were simulated. The 24-hour storm resulted
in higher peak flow discharges at RCMHP for both creeks, thus it was used in all subsequent
analyses.
DCB:MDL:emnlReponfJ-13 182.001 5 07/0 1 /98 Prepared By: Rick Engineering Company - Water Resources Division
Appendix 1 contains the 100-year, 24-hour HEC-1 analysis for the RCMHP watershed with the
existing detention facilities and ultimate development.
The second HEC-1 analysis modeled both existing and proposed detention facilities and
ultimate development. Several proposed detention scenarios were investigated and it was
determined that the most feasible scenario was the combination of four detention basins, all located
at proposed road crossings. Two of the proposed detention facilities are listed in the 1994 Master
Drainage Plan as Detention Basins BJB and BJ. These facilities are located immediately upstream
of RCMHP in Calaveras Creek. Both of the detention basins were designed as flow-by facilities.
A flow-by facility detains the higher creek flows, while allowing lower flows to pass through the
basin relatively undetained. The other two detention basins are further upstream in Agua Hedionda
Creek at the proposed roaa extensions of Melrose Drive (south of Aspen Way) and Faraday Avenue.
Both of the Agua Hedionda detention basins are flow-through types where all of the creek flow is
detained. All proposed detention facilities were designed to be outside DSOD's jurisdictional limits,
i.e., less than 50 acre-feet of storage volume and less than 25 feet high. Appendix 2 contains the
HEC-1 analysis of the 1 00-year, 24-hour storm for the RCMHP watershed with both existing and
proposed detention facilities and ultimate development.
Table 1 summarizes the results of both HEC-1 analyses. The table shows that with the
proposed detention basins, the peak discharge at RCMHP decreased by approximately 10 to 15
percent. Preliminary design of the proposed detention facilities are discussed below.
DCB:MDL:emn/Report/J-13 182.001 6 07/0 1/98
Prepared By:
Rick Engineering Company - Water Resources Division
Table 1
CalaverasCreek
Agua Hedionda (upstream of
confluence with CalaverasCreek)
Agua Hedionda (downstream of
confluence with CalaverasCreek)
Comparison of 1005year, 24-hour Peak Flow Discharges with Existing Detention Facilities
and with Both Existing and Proposed Detention Facilities
Ultimate Development
Rancho Carlsbad Mobile Home Park
1,910 1,550
8,050 7,600
9,950 8,970
DCB:MDL:ernn/RepodJ-l3 182.001 7 07/01/98 Prepared By:
Rick Engineering Company - Water Resources Division
Preliminary designs were performed for each proposed detention facility to determine the
outlet works requiredv'to achieve maximum detention, while maintaining the height and storage
volume below DSOD jurisdictional limits. The preliminary design of each detention facility and the
results for each detention facility design are described below.
The most upstream proposed detention facility in Agua Hedionda Creek is at Melrose Drive.
This facility will be a flow-through detention basin. Melrose Drive lzl~ls north-south and currently
ends just south of Aspen Way near the Carlsbad Corporate boundary. Future plans ea11 for the
extension of Melrose Drive to Palomar Airport Road. An existing reinforced concrete box (RCB)
culvert conveys flow under Melrose Drive and is 10 feet wide by 7 feet high. The existing Melrose
Drive embankment provides minimal detention because of the RCB's large capacity. Hydrologic
calculations show that a 36-inch diameter opening at this location will detain the peak flow discharge
from approximately 450 cubic feet per second (cfs) to 180 cfs. There are two alternatives for
creating the 36-inch opening. One is to replace the existing culvert with a 36-inch RCP and the other
is to construct a concrete barrier at the inlet with a 36-inch diameter opening. The resultant storage
volume and ponded water surface elevation (WSEL) with the new outlet works will be
approximately 41 acre-feet and 329 feet, respectively. This will create an inundation area of
approximately seven acres. The estimated outlet velocities for the first and second alternative will
be 25 and 13 feet per second (fps), respectively. The velocity under the first alternative is greater
than the maximum desired velocity of 20 fps. The velocity calculation assumed that the proposed
36-inch RCP was constructed at the slope of the existing culvert, which is one percent. If this
alternative is selected, the final culvert design should analyze methods for reducing the outlet
velocity, such as placing the culvert at a flatter slope or using multiple small diameter culverts. A
DCB:MDL:emnfReport/l-13 182.001 8 07/01/98
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Rick Engineering Company - Water Resources Division
conceptual plan for the second alternative is included in Map Pocket 3.
The other detention facility proposed for Agua Hedionda Creek is the Faraday Avenue flow-
bough detention basin. Currently, Faraday Avenue runs east-west and ends at Orion Street. The
extension of Faraday Avenue to Park Center Drive in the city of Vista is planned as part of Carlsbad
oaks North Business Park. The hydrologic calculations and preliminary design in this report were
based on the proposed embankment and topographic information shown on the Tentative Map for
Carlsbad Oaks North Business Park by O'Day Consultants, dated April 6, 1998. The calculations
show that a single 6-foot wide by 7-foot high RCB culvert will detain approximately 49 acre feet of
*- <<: ,
I- k. storage volume and will pond up to an elevation of 240 feet. The inundation area will be
\# t r( approximately seven acres. The 1 00-year peak discharge of 1,050 cfs entering the detention basin 7%' ..%
7-
will be detained down to approximately 780 cfs. The approximate calculated outlet velocity will be
19 fps. A conceptual plan for this detention facility is included in Map Pocket 4.
The two proposed detention facilities in Calaveras Creek are located just upstream of
RCMHP and were designed as flow-by basins. The first facility, Detention Basin BJB, is located
north of RCMHP at the proposed College Road extension and west of the proposed Cannon Road
extension. College Boulevard currently ends at El Camino Real. North of RCMHP, the proposed
College Boulevard extension runs roughly east-west. College Boulevard intersects the proposed
Cannon Road extension at the northeast comer of RCM". Cannon Road currently ends east of
Interstate 5 at Paseo Del Norte. The proposed Cannon Road extension alignment will be parallel to
Calaveras Creek and immediately north of RCMHP. The detention basin design consists of an
earthen embankment, outlet works, and a small berm. The embankment will have a 10-foot top
width and a 76-foot crest elevation with 2:l (horizonta1:vertical) side slopes. The outlet works
Prepared By. DCB.MDL.emn/Report/J-13 182 001 Rick Engineering Company - Water Resources Division 9 07/01/98
consist of a single 10-fpt wide by "-foot high RCB and a 48-inch RCP. The 48-inch RCP joins the
RCB downstream of the embankment. The RCB then extends to Calaveras Creek. An emergency
spillway is also provided. The small berm will run parallel to the creek for approximately 1,200 feet.
The berm will have an approximate 74-foot crest elevation, 10-foot top width, 2:l
@orizontal:vertical) side slopes, and a weir section. The weir section, located near the embankment,
will allow flow to enter the basin at an approximate WSEL of 73 feet. Hydrologic calculations show
that with the outlet works described above, a storage volume of approximately 49 acre feet will be
attained. The resultant ponded WSEL will be approximately 75 feet and the inundation area will be
approximately 15 acres. The peak discharge of 1,570 cfs entering the basin will be detained down
to 1,200 cfs. The approximate outlet velocity will be 19 fps for the RCB. See Map Pocket 5 for a
copy of the conceptual design of Detention Basin BJB.
The other Calaveras Creek detention facility, Detention Basin BJ, is located northeast of
RCMHP at the proposed College Boulevard extension and east of the proposed Cannon Road
extension. The earthen embankment will have a crest elevatien of approximately 8 1 feet, a top width
of 10 feet, and 2: 1 side slopes. An emergency spillway will be provided. Approximately 600 feet of
channel improvements upstream of the proposed embankment are necessary. The channel
improvements include grading the creek as follows: Trapezoidal-shaped grass-lined channel with
a 3-foot bottom width, 4-foot depth, and 2: 1 side slopes. The hydrologic calculations showed that
a 6-foot wide by 3-foot high RCB would detain the peak flow of670 cfs down to approximately 350
cfs. The inundation area is approximately eight acres and the ponded WSEL is approximately 76
feet. The detention basin stores approximately 48 acre feet of water. The calculated outlet velocity
will be approximately 19 fps. See Map Pocket 6 for the conceptual plans for Detention Basin BJ.
DCB:MDL:emn/Report/J-13 182.001 10 07/0 1/98 Prepared By: Rick Engineering Company - Water Resources Division
-.
As discussed above, with the addition of the proposed detention facilities, the peak discharge
at RCMHP is decreasid by approximately 10 to 15 percent. All four of the proposed detention
facilities were designed to fall below DSOD’s jurisdictional limits. Also, all the facilities are located
at existing or proposed rcad crossings and at least one foot of freeboard is maintained at the road
embankments. The results are summarized in Table 2, which contains results such as outlet works,
velocity, peak flow discharge into and out of the basin (Qin and Q,,J, storage volume, ponded WSEL,
and surface area.
DCB:MDL:ernn/Report/J-13 182.001 11 07/01/98 Prepared By:
Rick Engineering Company - Water Resources Division
n -
0 vl 0,
3
2
c;, a
cd Lt
Hydraulics
Hydraulic analyses were performed to determine the amount of silt removal and re-grading
required to minimize the 100-year flooding at RCMHP. In order to effectively analyze flood levels
in both Agua Hedionda and Calaveras Creeks, the U.S. Army Corps of Engineers HEC-2 Water
Surface Profiles program was used. The program is intended for calculating WSELs for steady
gradually varied flow in natural or man-made channels.. The effects of various obstructions such as
bridges and culverts may be considered in the computations. The program also has capabilities
available for assessing the effects of channel improvements.
The input parameters were based on channel and overbank roughnesses, 1 00-year discharge,
downstream WSEL, and topography. The channel and overbank roughnesses were determined by
field observations. The 100-year discharge was obtained from the HEC- 1 analysis in Appendix 2
modeling both existing and proposed detention facilities. The downstream WSEL was estimated
in the HEC-2 analysis by using the slope-area method. FEMA-approved HEC-2 cross-sections for
the area downstream of the site were included in the analysis. The 100-year discharge for the
downstream area was obtained using the split-flow analysis from the Flood Insurance Study.
The existing topography was based on June, 1995 topographic maps by Manitou
Engineering. The topography was used to prepare cross-sections of both creeks, as well as the
overbank areas. Since prior studies showed that the creeks were under-capacity, the original grading
plans for RCMHP were obtained and modeled in the HEC-2 analysis by using the channel
improvement option. The-original grading plans were prepared October 1 5, 1969 and approved by
the City on March 24, 1971. The original design consisted of a trapezoidal channel with an overall
length of approximately 1.2 miles and included both Agua Hedionda and Calaveras Creeks within
DCB:MDL:emnReport/J-13 182.001 13 07/0 1/98 Prepared By: Rick Engineering Company - Water Resources Division
RCMH~. The side slopes were 2: 1 (horizonta1:vertical) and the approximate bed dopes were 0.15
and 0.30 percent in Agua Hedionda Creek and Calaveras Creek, respectively. The bottom width of
Agua Hedionda Creek varied from 58 feet at the El Camino Real bridge to 44 feet upstream of the
confluence. The approximate channel depth was 1 1.5 feet. The bottom width and channel depth of
Calaveras Creek were four feet and nine feet, respectively.
A HEC-2 analysis was performed based on the original design. The HEC-2 results showed
that a large portion of RCMHP remained inundated by the 100-year flood. In order to increase
channel capacity, additional channel improvements were modeled in the HEC-2 analysis for the
downstream sections of both creeks. At the El Camino Real bridge, the bottom width was widened
to 87 feet. Within the next 1,400 feet upstream of the bridge, the bottom width then tapered down
to the original design bottom width of 44 feet in Agua Hedionda Creek and four feet in Calaveras
Creek.
The results of the hydraulic study are contained in Appendix 3. The results are also depicted
on the RO 1 00-year Floodplain Map in Map Pocket 7. The map shows that with the proposed
detention facilities and channel improvements discussed above, a majority of RCMHP will be
outside of the 1 00-year floodplain.
i
Maintenance Plan
This Maintenance Plan contains maintenance requirements for Aqua Hedionda and Calaveras
Creek within RCMHP. This plan also contains requirements for the four upstream detention basins.
It is vital that the creeks and detention basins be maintained on a regular basis to ensure an
acceptable level of flood protection for RCMKP. It is recommended that the maintenance described
DCB:MDLemn/Report/J-l3 182.001 14 0710 1 I9 8 Prepared By:
Rick Eneineerine Cornoanv - Water Resources Division
.. ...
.L .. .. ..
below be performed annually prior to the rainy season and after any storm event exceeding the 10-
year peak discharge.
I
Aqua Hedionda and Calaveras Creek must be maintained to prevent adverse siltation in each
creek. Siltation will reduce the flow capacity of the creeks and increase the likelihood of inundation
within the mobile home park. The first step is to devise a system for monitoring the silt level in each
creek. This can be done using metal posts with markings placed six inches apart. The posts should
be placed vertically in each creek at intervals not exceeding 500 feet. The posts should extend at
least two feet above the creek bed and must be embedded deep enough so that they will not be
moved by large creek flows. A geotechnical engineer should be consulted for the required
embedment depth. Once the posts are installed, the silt level can be easily monitored by
maintenance personnel.
maintenance crews to the design elevations.
AS the silt level reaches one foot, the silt should be removed by
The topographic maps have been reviewed to determine the siltation that has occurred in both
creeks over the past few years. The design of the creeks within the mobile home park is shown on
the grading plan for RCMHP approved March 24, 197 1. The creek bed elevations on the grading
plan served as the base elevations in determining the amount of siltation in each creek. A
comparison of the grading plan with a June 1995 topographic map indicates that the silt in Aqua
Hedionda and Calaveras Creek raised the creek beds as much as seven and five feet, respectively.
Therefore, siltation has occurred in Agua Hedionda and Calaveras Creek at a rate of up to 0.3 and
0.2 feet per year. Using these rates and an acceptable silt level of one foot indicates that portions of
the creeks could require maintenance approximately once every three to five years. It is important
to point out that this is a rough approximation because the creek siltation will depend on the
DCB:MDL:emn/ReportlJ-13 182.00 1 15 07/01/98
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.. . I, , , : -/
frequency and magnitude of future storm events. It is likely that future storm events will not mimic I
past events, Additionally, it is possible that maintenance has been performed on the creek between
1971 and 1995, which would affect the calculated siltation rates.
I
i 1
Maintenance is also required at each of the four detention basins. Maintenance will involve
keeping the entrance to each of the detention basin outlet facilities free from silt. Silt should be
removed from an entrance once the silt level reaches six inches above the entrance’s flowline
elevation, The amount of deposition should be easy to determine since each outlet facility is a
known size. The silt should be removed a distance of 10 feet upstream of the facilities entrance.
This will have minimal environmental impacts and will restore the capacity of the outlet facility.
I
I
!
I
The maintenance steps described above are essential for protection of RCMKP. The
maintenance must be performed routinely by qualified personnel and a sufficient budget should be I
established for the maintenance.
engineer specializing in water resources should be contacted.
If any questions arise during the maintenance, a professional I
Environmental Issues I
I The environmental issues associated with the Rancho Carlsbad Channel & Basin Project
have been addressed by the environmental consultant, RECON, and are summarized below. In
regards to the on-site channel silt removal and improvements, it is likely that no environmental I
mitigation will be necessary. In regards to the four proposed detention facilities, the direct impacts,
mitigation requirements, and potential indirect environmental impacts are listed by habitat type in
Tables 3,4, and 5, respectively. Direct impacts are from embankment construction. As mentioned
I
1
above, all of the embankments are within footprints of future roadways. Mitigation requirements I
DCB:MDL:cmn/Report/J-13 182.001 16 07/01/98 Prepared By:
Rick Engineering Company - Water Resources Division
I
assme 3: 1 for wetlands and 2: 1 for other. The goal is to mitigate on-site as much as possible.
Potential indirect impacts are based on the 100-year inundation area and will be further analyzed
during a subsequent design phase.
Table 3
Rancho Carlsbad Detention Basins - Direct Impacts (Acres)
Sycamore
Freshwater Marsh
0.4
Willow Woodland 0.42
Jurisdictional
Waters
Coastal Sage Scrub
Southern Mixed
Chaparral
0.07
0.12
1.50
I I I
Disturbed 9.4 1.1 0.26 2.24
DCB:MDL:emn/KeporUJ-13 07/01/9S 182.001 17 Prepared By:
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Table 4
Rancho Carlsbad Detention Basins - Mitigation Requirements (Acres)"
Sycamore
Woodland 0.42 I
Freshwater Marsh
I Willow Woodland
Jurisdictional
Waters
0.14
I
Coastal Sage Scrub
ChaDarral
1.2
* Assumes 3 : 1 wetlands; 2: 1 for non-wetland jurisdictional waters; 1 : 1 - 2: 1 for coastal sage scrub
and southern mixed chaparral.
DCB:MDL:emnlReport/J-13 182.00 I 18 07/01/98 Prepared By:
Rick Engineering Company - Water Resources Division
Table 5
Rancho Carlsbad Detention Basins - Potential Indirect Impacts (Acres)
Sycamore
Woodland
Willow Woodland/
Freshwater Marsh
Willow Woodland
Jurisdictional
Waters
Coastal Sage Scrub
Southern Mixed
Chaparral
Disturbed
2.0
3.3
2.67
0.3 1
0.6 0.35
14.0 6.5 1 3.05 3.92
DCB:MDL:emn;'Report/J-13 182.00 I 19 0710 1 /98 Prepared By:
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Probable Costs
Faraday Avenue Detention Basin
Melrose Drive Detention Basin
Detention Basin BJB
Table 6 below summarizes the probable costs associated with the Rancho Carlsbad Channel
$347,000
8,000
834,000
and Basin Project. These cost estimates are based on the preliminary design discussed in this report,
Detention Basin BJ
Silt Removal
Raise Affected Mobile Home Sites
i.e., the four proposed detention facilities and silt removal from Agua Hedionda and Calaveras <J
337,000
252,000
341,000
Creeks, as well as detention facility and channel maintenance. Several mobile homes are within the
revised 100-year floodplain. Therefore, costs have also been included for raising the affected mobile
$ij'r' >
Maintenance of Detention Facilities and
Channels per Occurrence
homes above the floodplain. These probable costs include construction costs, as well as the
$25,000
following additional cost items: Five percent of the construction costs for mobilization, 15 percent
for construction contingencies, and 15 percent for engineering and processing. Note that these costs
are based on the preliminary design and that a final cost estimate should be prepared during final
design.
Table 6
Opinion of Probable Costs
for Rancho Carlsbad Channel & Basin Project
DCB:MDL:emn/Report/J-13 182.001 20 07/0 1/98 Prepared By:
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I 4
i
Recommendations
In order to minimize the 100-year flooding in RCMHP, four upstream detention facilities and
on-site improvement; for Agua Hedionda and Calaveras Creeks are recommended. The detention
facilities will decrease the 100-year peak flow in RCMHP and the improvements wilI increase the
on-site channel capacity. The detention facilities are located at the following proposed road
extensions: College Boulevard, Melrose Drive, and Faraday Avenue. The preliminary design
requirements for the detention facilities and channel improvements are discussed in previous
sections. Fourteen mobile homes are within the revised 1 00-year floodplain limits. These can be
removed from the floodplain by temporarily transporting the affected mobile homes and re-grading
the sites to one foot above the floodplain. A preliminary cost estimate for this work is presented in
the “Probable Costs” section of this report. Also included in the “Probable Costs” section is the
estimated maintenance cost for the detention facilities and channels, as outlined in the “Maintenance
Plan.” Final hydrologic and hydraulic analyses, cost estimates, and environmental assessments
should be performed during the final design phase.
It is also recommended that a Rural Flood Water Storage Easement be prepared for each
detention facility. The purpose of the easement is to define the 100-year inundation limits. The
easement should be written so that it can be modified in accordance with future development. An
example of the text that can be included in the easement description is as follows:
WE HEREBY GRANT TO THE CITY OF CARLSBAD, A MUNICIPAL
FLOOD WATERS OVER, UPON AND ACROSS THE PORTION OF LOT XX,
DESIGNATED AS “RURAL FLOOD WATER STORAGE EASEMENT GRANTED
HEREON”, ALL AS SHOWN ON THIS MAP WITHIN THIS SUBDIVISION,
RESERVING, HOWEVER, TO THE OWNER OF THE FEE UNDERLYING SAID
EASEMENT HEREM GRANTED TO THE CONTINUED USE OF THE SURFACE OF
SAID REAL PROPERTY, SUBJECT TO THE FOLLOWING CONDITIONS: THE
CORPORATION, EASEMENTS AND RIGHTS-OF-WAY FOR THE STORAGE OF
DCB:MDL:emn/Report/J-13 182.001
0710 1 I98 21 Prepared By:
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ERECTION OF BUILDINGS, WALLS, OR OTHER STRUCTURES SHALL BE
PROHIBITED UNLESS IT CAN BE DEMONSTRATED THAT THE STRUCTURE
DOES NOT EFFECT THE STORAGE OF FLOOD WATER AS APPROVED BY THE
DEPARTMENT OF PUBLIC WORKS. FENCES THAT ALLOW THE PASSAGE OF
WATER, OK MINOR GRADING WITH THE BALANCE OF CUT AND FILL SHALL
NOT BE PROHIBITED. NOTHING CONTAINED HEREIN SHALL BE CONSTRUED
TO ASSIGN ANY MAMTE"CE OR LIABILITY RESPONSIBILITIES TO THE CITY
OF CARLSBAD.
DCB:MDL:emn/Rcport/J-13 182.001 22 07/0 1/98 Prepared By:
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References
County of San Diego, Department of Public Works, Flood Control Division Hydrology Manual,
revised January, I985 and minor update April, 1993.
Grading Plan Rancho Carlsbad Mobile Home Park JN Y309-4 by South Bay Engineering, 10/15/69,
approved for grading within property limits 3/24/7 1.
Flood Insurance Study for San Diego County, California and Incorporated Areas by Federal
Emergency Management Agency, June 19, 1997.
“Flooding Issues Related to Agua Hedionda Creek for Rancho Carlsbad Mobile Home Park” by H.
Chang, 5/96.
“Floodplain Boundary and Floodway Delineation for Agua Hedionda Creek” by H. Chang, 9/91.
4
“Hydraulic and Scour Studies for Proposed Cannon Road Bridge on Agua Hedionda Creek” by H.
Chang, 6/97.
“Hydrological Study for Northeastern Carlsbad Basins of CalaverasLake Creek and Agua Hedionda
Creek” by H. Chang, 7/89.
“Hydrology & Hydraulic Studies for Carlsbad Oaks North Business Park” by H. Chang, April 1997.
Master Drainage and Storm Water Quality Management Plan, City of Carlsbad, California, March,
1994.
“Rancho Carlsbad Drainage and Floodplain Study” by Rick Engineering Company, JN 8845,6/7/83.
“Rancho Carlsbad - Phase I1 Pre1imkm-y Review Study” by Site Design Associates, Inc., April 22,
1997.
San Diego County Soil Interpretation Study Ground Cover maps by Soil Conservation Service,
1969.
Soil Survey San Diego Area, California maps by Soil Conservation Service and Forest Service,
, December, 1973.
hepared By: DCB:MDt:emn/ReponlJ-l3 182.001
Rick Engineering Company - Water Resources Division 23 07/01/98
4330 LA ~OLLA VILLAGE DRIVE - SUITE 330
SAN DIEGO, CALIFORNIA 92 I 22-6203
TELEPHONE: (6 19) 535-9380 FACSIMILE: (6 19) 535-938 I
E MAIL: LLOWN I82@AOL.COM
March 18,1999
Clyde Wickman v* \\a Engineering Department
City of Carlsbad
2075 Las Palmas Drive
Cdsbad, CA 92009-1 576
Re: Rancho Carlsbad Country Club Estates (the “Property”)
Rancho Carlsbad Owners’ Association, Inc. (the “HOA”)
Master Drainage Plan - Lake Calavera Creek & Agua Hedionda Creek
Resolution No. 97-44; RC Security Agreement [Contribution to Master
Drainage Plan]; Hold Harmless Flood]; Ordinance No. NS - 392 [Zone Change]
FILE NO: RCHOA - 450
Dear Clyde:
This correspondence is written on behalf of the Rancho Carlsbad Owners’ Association, Inc.,
a California non-profit mutual benefit corporation (the “HOP), which is the managing and
operational entity for the Rancho Carlsbad Country Club Estates and the owner of Lots numbered
2,3, and 4; with Lot number 1 being owned by the members of the HOA. The purpose of this
correspondence is twofold: i) to determine the status of the improvements for Lake Calavera Creek
and Agua Hedionda Creek (collebtively, the “Creeks”); and ii) to object to the taking of the HOA’s
property on Lot 4 for the creation of a detention basin. t.
As you aware, we all spent months, if not years, discussing the Master Drainage System and
the flood hazard, if any, on the Property. Finding No. 3, A of the enclosed Resolution No. 97-44
amended Finding No. 11 of the conditions of approval of the Tentative Parcel Map (MS 96-08)
contained in Planning Commission Resolution No. 4033. This finding, in summary, stated that the
City would mitigate flooding and drainage impacts pursuant to the Master Drainage Plan (approved
by City Council Resolution No. 536-4133 , Uecember 3, 1996) and that “these improv‘emnts will
bknefit the owners of the mobilehome park by reducing flooding impacts and improving drainage
to the park.’’ To implement that goal of the City, the subdividers were required to grant easements
in connection with the Creeks and to pay over ten years the sum of $3 18,000 under the terms and
conditions of the Security Agreement. [Resolution No. 97-44 has been attached for ease of
reference.]
I
Clyde Wickham
Engineering Department
City of Carlsbad
March 18,1999
Page 2
RCEOA - 450
The owners of the Property have done all that has been required of them under the terms of
the conditions of approval. Certain resident households have begun to notice that the Creeks and
adjacent banks are suffering fiom erosion and other deteriorating conditions. Therefore, please
provide to the HOA a schedule of what work you plan for both of the Creeks, when you plan to
commence the corrective work on the creeks, and the plans and drawings for said work. The HOA
is anxious to coordinate this work with your office to assure continued integrity of the property.
It has come to the attention of the HOA that the City caused Rick Engineering to prepare a
new FEU map and to submit that map to FEW. The HOA, nor its members, were ever given the
opportunity to comment on or to review said map before it was submitted. It is the understanding
of the HOA that the map is significantly different from the FEU map which was reviewed as part
of the subdivision process of the Property and that the small detention basin which existed on Lot
4 was substantially increased such that the revised detention basin effectively takes all of Lot 4. Lot
4 is zoned RMHP. [See, Ordinance No. NS-392, attached for ease of reference]. The actions in
removing that Lot from usage by the HOA constitutes a taking of private property. Further, it
appears that the Creeks will not be improved as discussed and paid for by the HOA.
%
In condusion and to S-, the HOA requests the following:
1. e Creeks;
a) Does the City intend to improve both Creeks?
x b) Please provide the current improvement plans, sketches, maps.
c) Please provide the current time line for the commencement and completion
of the Creek improvements.
If the City does not intent to improve one or both creeks, how do we remove
the condition which requires the payment of $3 18,000 for the improvements,
because the HOA will need to do the improvements rather than the City.
d)
2. Lot 4 [Recreab 'onal Vehicle Lot];
a) Has the City submitted a plan to FEMA which constitutes a substantial taking
2
Clyde Wickham
Engineering Department
City of Carlsbad
March 18,1999
Page 3
RCHOA - 450
of that property?
b) Please provide a copy of the FEMA map which the City caused and directed
Rick Engineering to make on behalf of and for the City.
3. Notices:
By this correspondence the HOA is requesting that notice of all city actions which
will, or may, impact the Property be forwarded for the HOA, and its 3 10 members,
to:
Pat Kurt, President
Rancho Carlsbad Owners' Association, Inc.
5200 El Camino Real
Carlsbad, CA 92008
Sue Loftin, Esq.
Attorney for Association
4330 La Jolla Village Drive, Suite 330
San Diego, CA 92122
We look forward to working with you, and your office, to resolve the above mentioned
matters to insure the health, safety and welfare of the residents of Rancho Carlsbad Country Club
Estates.
Sincerely, d
L. Sue Loftin, Esq.
LSL:seb
cc: Pat Kurth, President, HOA
Marty Orenyak, City of Carlsbad
Ron Ball, City Attorney, Carlsbad
3
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4
_-
February 2,2000
Rancho Carbbad Owners' Association, Inc
Atlention: Board of Directors 5200 El Camino Real Carlsbad. CA 92008
DRAINAGE DETENTION BASIN BJ
Dear Directors:
The C~ty of Carlsbad is curren ly in the process of preparing an Environmental rmpaci Report which covers the construction cf Collage Roulevard, Cannor1 Road. the remainder of the Caiavera Hills Master Pian devclopnenr end two blaster Drainage Plan detention basins
located within and adjacent to ytur mob!le how park devebprnent. As yol: may recall, when the Rancho Carlsbac Mobi!e Home Park (RCMVP) xnversion project was approved
by the City. there was considerab!e discussion regarding the adequacy of the existing
drainage facilities within the park to protect existing home owners against the effect cif Rood waters. As part of the conversion procsss, the City commissioned a private engineerkg firm to develop a flood control plaq for the surrcunding drainage basin which would reduce the flcod risk to the park residents and adjacent property owners.
f 4. ..
The resutts of the engineering s:udy commissioned' by the City indicate the need far three
drainage detention basins to prevent future floodirng of the RCMH property. In addition, the
study recommended some minor channei niodificaticns at the confluence of the kgua Hedianda and Calavera Creeks near the northwest mmer of the RCMHP. One basin wi!! be sited along a tributary of the Agua Hedionda Creek just east i3f the future extension of
Melrose Drive near Palomar Airpart Road. The other two basins are proposed to be sited
east of the existing mabile home pErk hornss along tributaries Qf Calaveras Creek. These two basins were previously identifed in the Ci;Y's Mastor Drainage and Storm Water Qualit)i Management Plan as basins BJ ard BJB. Basin 6JB is proposed to be !mated on the Robertson property at the northeast corner of the fdture Cannon Road and Colieye Boulevard 'intersecticn. Basin IS proposed tc Se located 01 the FiCMHP property in the
general IOGI~~OR of the existing RV storage area. Given the nature and required size of the proposed basins, these two sites zre the only feasible locations for these proposed facilities.
The City is proceeding with the design and construction of Basin 6JB toge:her with the channel improvements. We are presently irr :he preliminary engineering ana emir-anmental
review stages for these improvements. Basin BJ will most likely be COflstiuCted by a developer as part of the extension of Cokge Eoulevsrd soc;th of Cannon Rcad wtllsh may
be a requirement of Rancho Carlsbad Partners property adjacent to your mobile home park. Due to the adjacency of College Boulevard to Basin BJ and SJB we decided to include the environmental review for these basins it? the Environmental Impact Repon (EIR) for the two roads. The City has already conducted two scoping meetings fcr the proposed EIR: however, due to a mix up in the noticing of thess meetings most of the residents within the
RCMHP were not properly notified. The City intends to host another scoping meeting in the
--. I____---- - - --.- - - -- 1635 Faraday Avenue - Carlsbab, CA 92008-731 4 * (760) 602-2720 FAX (760) 602-8562 t3
.E
I
L
near future so that the Associatian and indivicluai residents mag provide early input intc the environrnentai review process. You will receive notification of this additional sccjping meeting from the City in the next fe;N weeks. The Association and residents of the RCMHP
will also be provided ample opportunity to revie* and comment on the draft EIR prior to its
consideration by the City Council.
It is my understanding that a representative from Rancho Carlsbad Partners has or will be contacting your association regarding relocation of the RV parking lot area. You; assistance in helping the Rancho Carlsbad Partners developer in finding a suitable alternative site fclr
the. RV storage area would be greatly appreciated.
If you need further assistance or clarification or( this matter please feel to give me a call at
(760) 602-2739.
Since re1 y ,
. .. *,..-. . . QJL
DAVID HAUSER Deputy City Engineer Planning and Programs Division
DH:jb
c. Deputy City Engineer for Development Associate Engineer - Wickham Senior Planner - Muncrz
City Project Engineer Consultant - Jacobs City Project Engineer Consultant - Peterson Kenneth J. Discenza. Site Design Associates, Inc.
..
L
8
P.82
May 30,2000
L. Sue loftin
4330 La Jolla Village Drive, Suite 330
San Diego, CA 92122-6203
RELOCATION OF RCMHP RV AREA FOR PROPOSED DRAINAGE BASIN BJ
This letter is written in response to your letter of March 27,2000. I would like to begin
by thanking you for your patience in awatting my response to your letter and by
providing you with a brief update cn the current status of the CollegelCannon roadway
and drainage basin projects. The screen check of the EIR document which includes
these two projects together with the revision to the Catavera HiHs Master Plan has been routed for internal City review. Our comments are due June 1. Once the screen check is complete, the document will then be routed for public comment,
The Calavera Hills developer has been moving forward on the design plans for Cannon Road Reacb 3 and College Boulevard Reaches 3 and C (see attached map), The City
is moving forward with the preliminary plans for College Boulevard Reach A , Cannon
Road Reach 4 and Basin BJB. The Rancho Cailsbad Partners will be required to
provide preliminary and final design for Basin BJ and final design for College Boulevard
Reach A It is expected that College Boulevard Reach A (at least that portion across the Rancho Carisbad Property) and Basin BJ wil! ultimately be constructed by the Rancho Carlsbad expansion devefopment.
The timing of these projects Is dependent upon many factors and therefore not precisely known at this time. The EIR for the roadways and basins should be complete
by early next year. McMiilin has indicated a desire to move forward with their projeci by
spring or summer of 2001. The CIty anticipates mow9 forward with the construction of
Basin 838 and the Calavera Creek dredging and improvement at about the same time'
nowever, it will first be necessary tg secure the easements and agency permits before proceeding with construction.
The planning submittal for the Rancho Carlsbad Partnership project has yet to be
deemed complete so their project has a considerable ways to go before it is ready for
C9nStrwtiofl. Of course, a major issue which requites resolution prior to their receiving
project approval involves the relocetion of the RV storage lot, At this time no decisions
have been made on the appropriateness 0: suitability 5f any replacement site.
Ywr request to enter into a three way development agreement with the City, developer
and RCMHP Association has merit and shculd be discussed w:th the Project Enginwr
---- -._ __ ___ .- __ -.-- .-, .- - - -. -----
1835 Faraday Avenue Carlsbad, CA 92008.7314 (760) 602-2720 FAX (763) 602-8562 @
I'
JUt4-81-@8 04:.?.4 FM LAN OFFlCE 3F LOF-TIb4 8585359381 2 P. 03
for this development, Mr. Glen Van Peski. Glen is a consultant working for the City on mobile home park expansion project and has indicated to me he will be happy to meet
with you to discuss this matter at your convenience. Glen's telephone number is (760) 720*0500.
If you have further questions or comments on the expansion project they should be
referred to hlr. Van Peski, If you have any question or comments on the formation of the bridge and thoroughfare district or design and construction of College Boulevard Cr Cannon Road , please feel free to write or to give me a call to discuss at (760) 002-
2739.
Davld Heuser
Deputy City Englneer
C Public Works Director
Glen Van Pesky
Principal Civil Engineer - Hammann Associate Planner - Lynch
CITY Cf OCCEkNSIDf
BRIDGE & THOROUGHFARE DI
n
Memo
TO: RCOA Board of Directors
From: Pat Kurth
CC: Date: 09/27/00
Re: Meeting with City Representatives
Present: City - David Hauser, Deputy City Engineer and Rick Engineering Co.
Sue Loftin, Pat Kurth and Bill Amold
RANCHO CARLSBD CHANNEL AND BASIN PROJECT AGENDA
Project Overview - Rancho Carlsbad Channel and Detention Basin BJB Project
Goal of Flood Plain Special Use Permit Application
The Rancho Carlsbad Channel and Basin Project consisting of the construction of Basin BJB and regrading of both Calavera Creek and Aqua Hedionda Creek within the Rancho Carlsbad Mobile Home
Park will require a Special Use Permit.
Before they can remove the several layers of silt from the two creecks within the complex the constudion of the detention basin must be done.. . ..before they can construct the detention basin they
must acquire the property, which is owned by the Robertson family , and lies north of Rancho
Carlsbad and immediately northwest of the intersection of the proposed College Blvd and Cannon Rd.
extesions.
Before they can go further Environmental Impact study must be completed and they must make
decisions regarding the height and position of the roadbeds for College and Cannon Roads.
We discussed briefly how they would clean out the creekbeds, the care of the creekbanks and the replanting and care of same.
CONCLUSION: Project is probably about two to three years in the future. Sue requested a change in
the SUP Application before we sign it and they agreed. Will send revision to Sue Loftin who will review
and OK for signing. wlll go into this more at Board Meeting
Page 1
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August 29,2001
Mr, David Hauser
Deputy City Engineer
City of Carlsbad
1635 Faraday Avenue
Carlsbad, CA 92008
,/’
EL CAMlNO
i 1,.
RE AL m CARLSBAD. CA 92008-3899
Re: Rancho Carlsbad Channel & Basin Project (Job #13182)
Dear Mr. Hauser:
The above referenced project was commissioned by the City of Carlsbad, and a professional
report dated June 30, 1998 was prepared by Rick Engineering Company. Prior to this date, the
City had required our community, Rancho Carlsbad, to agree to an assessment of $3 18,000, to be
paid over 10 years with interest, to cover “our share of the dredging of our stream channels”. To
date, we have made three annual payments and are due to make our fourth payment next
February.
The Rick Engineering report clearly points out the serious silting of our stream beds, and the
need for dredging and annual maintenance. A visual inspection of our streani channels by a
layman clearly indicates excessive silting. We would urge you or your staff to observe for
yourself.
The Rick report addresses this issue starting on page 13. In comparing the original design of the
creek beds in 197 1 with a 1995 topographic map, they concluded “that the silt in Aqua Hedionda
and Calaveras Creeks raised the creek beds as much as seven and five feet respectively”.
From persona1 observation, the silting on Aqua Hedionda raised the stream bed 1 !4 feet in two
years, 1999 to the spring of 2001. We believe we are closer to 10 feet today, not seven, and
growing at a higher annual rate than estimated in the report.
To date, however, there has been no movement to begin dredging, and, in fact, we have been led
to believe that the construction of the proposed detention basins (4) niust preceed any dredging.
To wait until the detention basins are constructed, however, could take years. The Calavera
Creek basins, BJB and BJ are part and parcel of the Bridge and Thoroughfare District #4 Project
A rI M I FJ IS T H AT I o N
PHONE \iG0)438.0333
FAX (7601436-1806
which might be completed in one to three years. But the construction of the planned detention
basins for the Aqua Hedionda are years away, and it is this creek that carries 80% of the water
flow and has the most serious silting, in our opinion.
We strongly urge the City to expedite plans to begin this dredging work as soon as possible.
Another winter, rainy season is approaching. A ten year storm would cause some flooding as it
did in late 1994. The 1994 storm caused the Calaveras Creek to overflow its banks and flood the
adjacent street, Don Rodolfo, to a deepth of approximately two feet. Fortunately none of the
home were inundated. Who knows when the 50 year or 100 year storm will hit.
We are sure the City Council would shudder to read newspaper headlines about a senior
community suffering serious flooding caused in part by the City’s delay in implementing its own
remedial plans.
We would appreciate a reply indicating what action the City is planning and the timetable.
Sincerely,
Russ Kohl, President
Rancho Carlsbad Owner’s Association
Bill Arnold, Chairman
Highway & Land Advisory Committee
cc: City Council
Sue Loftin
Rick Gibson
- City of Carlsbad
Rancho Carlsbad Homeowners Association
3366 Don Diablo Drive
Carlsbad, CA 92008-3914
Attn: Pat Kurth, President
VIA US MAIL
RE: FLOODPLAIN SPECIAL USE PERMIT APPLICATION
RANCHO CARLSBAD CHANNEL AND BASIN PROJECT
Dear Property Owner:
The City of Carlsbad Municipal Code requires that a Floodplain Special Use Permit must be
obtained before construction may begin within any area of special flood hazards. The
Floodplain Special Use Permit (SUP) application package, which also includes the required
California Environmental Quality Act (CEQA) environmental documentation, is heard by the
Planning Commission and, if approved, will result in receipt of both the Floodplain SUP and the
required CEQA environmental clearance. Additional permits will be required from the various
State and Federal resource agencies.
The Rancho Carlsbad Channel and Basin Project consisting of the construction of Basin BJB
and regrading of both Calavera Creek and Agua Hedionda Creek within the Rancho Carlsbad
Mobile Home Park lies within a Special Hazard Area and will require a Special Use Permit (See
attached Figure 2 and Figure 3). The City has prepared the SUP application including all
environmental documentation and associated technical studies. In order to submit the
application to the Planning Department, the affected property owners of record must provide
signatures to the enclosed “Land Use Review Application” and “Disclosure Statement”
documents.
If you are in agreement with moving the SUP process forward, please sign the aforementioned
documents and return in the enclosed envelope. If you have questions or would like to meet to
discuss the process or review the SUP application, please contact the undersigned, David
Hauser, Deputy City Engineer at (760) 602-2739 or Dick Jacobs, Consultant Project Manager,
at (760) 929-0135.
We appreciate your assistance in moving this important project forward.
Respectfully,
David Hauser
Deputy City Engineer
Copy: Public Works Director
1635 Faraday Avenue - Carlsbad, CA 92008-7314 - (760) 602-2720 - FAX (760) 602-8562 @
u
DATE: October 2,2001
TO:
RE: CREEKDREGING
The Rancho Carlsbad Board of Directors
On Tuesday, September 25,2001, Richard K. Jacobs of Dick Jacobs Associates, a consultant to
the City, along with David Hauser, Deputy City Engineer, walked our creek beds to ascertain the
extent of the silting and how they might attack the problem
)c
Due to environmental constraints, they must try and protect Sycamore and Oak trees along the
banks. Some other trees might have to be removed in the dredhg process. The main creek, the
Aqua Hedionda, does not present any major problem, but the Calaveras creek is another story.
Both Sycamore and Oak line the banks along with many other types. Due to the narrow creek
bed, the fear is that the protected trees might be weakened and topple into the creek, or their root
systems be damaged and die, They will bring in a tree expert to evaluate the situation. They will
also be looking at Eo other alternatives,
(1) Enlarging the BJB Basin on the Robertson property. That would re-classify it as a Class C
Dam, subject then to another whole set of State regulations, omonsider laying a storm drain
or construct a drainage ditch parallel to the creek north of our wall to handle any storm surge
water that would overtax the nature creek drainage.
.-- y
I also questioned the silting under the El Camino Avenue bridge and beyond. Mr. Hauser
conceded that dredging under the bridge mi t be necessary. The Coastal Commission has ? jurisdiction beyond that and getting their -+- c earance to do anything, ifit were deemed necessary, 8
would present the City additional regulatory rules to conform to.
We have obviously gotten their attention. Solutions, however, may still take some time and could
cloud and/or even delay planned road extensions.
Bill Arnold
i ... .<,e , : .. .. I ' ; 128. No&H HELM AVENUE ' '. .' '. ' ' . .' ,(e&) 720-0442. ; SOWA BEACH, CA 92075-1 1.40 ' ' . ' .. .'-_ ,. .FAX' (858) '740-0443 :. , email: dickjacobsassociates@wqrldnet.att.net . . '.:.. , ' -. . :. . c- ; .._ .I I. . _,. -' --. ..-.. :- ~.- - ... . . .. .. i. .. ..
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By: WILSON ENGINEERING; 760438$)173; Mar-4-02 9:31; Page 2f7
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CITY OF CARLSSAD AGENDA SILL
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M86br Storm Drain Dcltmtion Baain BJB la sfted et the northeast intersection of the future+ ax"I d CoRwe Baulward and Cannon Road on prop owned b the Robertson Ranch
kdlhge Boulevard and Cqnnon Road, was ln#ktted 1999. Due to the fact that . Defsntiafi Basin BJB abuts Ccdega Bcrulevard and Cannon Road, the envfronmbnbl processing for PetBn@on Basin BJB was remom from the scope of the stand-alone CkY GlP drainage pf0.d and Included in the pr~wssft=~g for EIR $8-2, In sddition, due to ttte! hlgk apprabd value of the right-0f-W)' for Detention Bash 6JB gnd with the impending development of U'W RO-n Ranch and the constnrotbn of Cannon Road and COH e Boulevard, betention Rash BJ5 was rsmeved from the scope af the CXy c1P drsrhage p&t. ~&uI~# Basin BJB is scheclulrsd to be constructed by the developer with the construction of Cannon Road and Colla e BOUl#ard.
work kerns to mmplete fhO Silt Removal antGhannet 1 4 provemen s w tfih the RCMHP, identified as the Rancho Carisbad Channel Maintenance Project,
see Exhibit I . The Calavera HIIS Master Plan Amendment 3 IR (EIR 9 $: 2), whlch includes the
The attached consultant agreement and sco e of work [see Exhibit 3 erefom inc 7 udes only the
RECEIVED
'1 MAR 0 4 2002
ent By: WILSON ENGINEERING; I 78043001 73; Mar-4-02 Q:32; Page 3/7
Since the total pro’ed oost is esUmated tw be $1,280,500 and the wmnt spprapriatton is only
Drainage Area fund. $1,t2OIU00, an a d dltbal appropriation of $140,5# will be required from the Planned Local
2 A
3nt.B~: WILSON ENGINEERING; 78043801 73; i Mar-4-02 9:33; Page 4J7
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LOCAT
August 6,2002.
John H. Robertus Executive Officer
CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD gl74 Sky Park Court, Suite 100
San Diego, CA 92123
RANCHO CARLSBAD MOBILE HOME PARK - AGUA HEDIONDA CREEK MAINTENANCE
(RECON NUMBER 3001B)
Dear Mr. Robertus:
End& Is an application for a 401 State Water Quallty certification for the proposed
maintenance to be conducted by the City of Carlsbad on the channelized porfion of AguaHedionda Creek within the Rancho Carlsbad Moblie Home Park (RCMHP). This sedion of Agua Hedionda Creek was channelized into an earthen trapezoidal channel
in the 1970's to provlde flood protedlan for the RCHMP. The proposed project would
remove accumulated sediments from the meek to return the ChanRel capacity io its original design. In addition, the applioant Is proposing a long-term maintenance plan to monitor and remow accumulated sedlment In the future. The maintenance Is required to provlde better Rood protection for the RCHMP and it is an integral part of the regional drainage plan.
The proposed project would dredge approximately 30,000 cubic yards of material from the creek bed, Thls would temporarily impact 3.7 acres of herbaceous wetland and 0.5 acre of
channel bank, No native riparian plant communities occur along this section of the creek. One western sycamore and fwr Isolated ywng willow trees would be removed from the banks during the maintenance activities, the remainder of the trees to be removed are non-native. The herbaceous wetlsnds are comprised of native and non-native annual and perennial plants that temporarily colonize the sandbars of the creek bed during low ftaw
periods. These sandbars and scattered vegetation are scoured annually durfng seasonai storm flaws. No woody trees or shrubs currently grow or can become estabfished In the channel bed due to its dynamic nature.
Long-term maintenance of the channel capacity is required to maintain the level of flood
protection achieved by the proposed project. A conceptual maintenance plan has been prepared that contains the proposed threshold of sediment accumulation that would trigger
future sediment removals. This threshold is around two feet of accumulated sedfment. Sedimentaccumulation would be monitored and once the threshold Is reached excess
sedlment would be removed. it is estimated that the two-foot threshold would requtre the removal of approximately 8,000 cubic yards periodically. The frequency of future
maintenance Is dependent on how fast sediment accumulates in the channel and Is expected to be Varkibl8 over time.
--
1635 Faraday Avenue Carlsbad, CA 92008-7314 (760) 602-2720 e FAX (760) 602-8662 @
August 8,2002 RANCHO CARLSBAD MOBILE HOME PARK - AGUA HEDIONDA CREEK MAINTENANCE
(RECON NUMBER 30018)
Page 2
The applicant has submitted a 404 permit application-to the U.S. Army Corps of Engineers and a 1601 Streambed Alteration Agreement appllcation to the California Department of
Fish and Game. Copies of these applications are included in this package. Other supplemental lnformatlon, includhg reports on biological resources and wetlands are also included 8s part of this application.
Sincere&,
DAVID'~AUSER Deputy City Englneer
Enclosure( 6)
c: Publlc Works Director (wla endosures) Deputy Public Works Director, Engineering Services (wlo endosures) Principal Planner Don Rldeout (do enclosures) Senior Planner Erlc Munor [w/o endosures) Dick Jacobs, Dick Jacobs Associates (wlo enclosures)
Gerry Scheid, RECON (wlo enclosures) Dennis Bowling, Rick Engineering (wto endosures)
.. .. . .. -
'I
August 6,2002
Regulatory Branch
U.S. AM CORPS OF ENGINEERS
16885 W. Bemardo Drive, Suite 300A San Diego. CA 92127
. RANCHO CARLSBAD MOBILE HOME PARK - AQUA HEDIONDA CREEK MAINTENANCE (RECON NUMBER 30018)
To Whom It May Concern:
This letter is to seNe as notification of the submittal of an application for a 404 Permit for the proposed channel maintenance project along Agua Hedionda Creek within the Ftancho Carlsbad Mobile Home Park (FGMHP). In addition, the applicant requests approval of a long-term malntenance plan to remove accumulated sediments In the future. This application package outlines the Impacts to jurisdictional waters for the proposed maintenance project and presents the conceptual maintenance plan. Endosed you will find the required information for the 404 Permit application for your review.
The name, address, and telephone number of the applicant is:
City of Carlsbad
1635 Faraday Avenue
Carlsbad, CA 92008 Contact: Davld Hauser Telephone: (7601 602-2739
The proposed channel maintenance project site is located within the RCMHP in the City of
Carlsbad. RCHMP k located along Agua Hedionda Creek east of El Camino Real, north of College BOUleMrd, and south of Tarnarak Avenue. The section of Agua Hedionda Creek within the project area begins downstream of the bridge at El Carnino Real and continues
30 sec. north latitude; 117 deg. 17 min. 30 sec. longitude.
Applications for the following permits, agreements, snd certifications have also been applied for:
e e e
. approximately 2,400 feet upstream. The latltude and longitude of the site is 33 deg. 08 min. ..
California Department of Fish and Game 1603 Streambed Alteration Agreement
Regional Water Quality Control Board 401 State Water Quality Certification CEQA certlflcation by the City of Carlsbad
i635 Faraday Avenue Carlsbad. CA 92008-7314 (760) 602-2720 FAX (760) 602-8562 @ - --- . - -
August 6,2002 RANCHO CARLSBAD MOBILE HOME PARK - AGUA HEDIONDA CREEK MAINTENANCE (RECON NUMBER 30018) Page 2
The proposed project is not within the coastal zone, will not affect navigation, will not impair tribal rights, and will not affect any wild and scenic rivers. Restfictians on the use of heavy equipment in wetland areas am contained in the environmental condltlons of approval along with appropriate measures to control erosion and sedimenfatlon. The movement of aquatic Me wlll not be Impeded by this project.
The applicant requests that the proi& be considered under the Nalionwlde Permit #31 “Maintenance of Existing Flood Control Facilities.” If the Corps agrees to this request, informatlon can be provided that would estabfish the maintenance baseline for the channelized sectlon of Agua Hedionda Creek wlthln the RCMHP. If you have any questlons regarding the information provided to you in this application package, please call me.
Sincerely,
Deputy City Engineer
Enclosures
c: Public Works Director (wla enclosures) Deputy Public Works Director, Engineering Sefvlces (w/o enclosures) Prinapal Planner Don Rideout (wlo enclosures) Senior Planner Eric Munoz {wh enclosures) Dick Jacobs, Dick Jacobs Associates (wlo enclosures)
Gerry Scheid, RECON (w/o enclosures) Dennis Bawllng, Rldc Engineering (wlo enclosures)
..
August 6,2002
Ms. Jeanle Negus
Streambed Alteration Team CALIFORNIA DEPARTMENT OF FISH & GAME 4949 Viewridge Avenue San Dlego, CA 92123
RANCHO CARLSBAD MOBILE HOME PARK - MAINTENANCE OF AGUA HEDIONDA CREEK (RECON NUMBER 3001 B)
Dear Ms. Negus:
Enclosed is an application for a Streambed Alteration Agf'eef~~ent to authorize the removal of accumulated sediments within the channelized portion of Agua Hedionda Creek within the Rancho Carlsbad Mobtle Home Park (RCHMP). In addition, the applicant requests the approval of a long-lm maintenance program that would allow for the removal of accumulated sediment In the future.
The proposed maintenance project would remove approximately 30,000 cubic yards of
sediment from the channslked portion of Agua Hedionda Creek wlthin the RCMHP. This sediment removal would result In temporary impacts to the exjstlng channel as detailed in the InfarmatIan provided with this application. Future maintenance activities would remove up to
8,000 cubic yards of sediment once lhe hnro-foot accumulation threshold is reached. Thesemaintenance activities are required to return the channel capacity of Agua Hedhda Creek to its orlginal design, therefore, minimizing the area inundaled by large floods (e& 100-year event).
Please review the application and information and call me with any questions or additional informational needs.
Sincerely, Ddff DAVlD HAUSER
Deputy City Engineer
Enclosures
c: Public Works Director (wlo enclosures) Deputy Public Works Director, Engineering Services (wlo enclosures) Principal Planner Don Rideout (WID enclosures) Senior Planner Eric Munoz (wlo enclosures) Dick Jambs, Dick Jacobs Associates (wlo enclosures)
Gerry Scheid, RECON (wlo enclosures) Dennis Bowting, Rick Engineering (wlo enclosures)
-
1835 Faraday Avenue * Carlsbad, CA 92008-7314 * (760) 602-2720 FAX (760) 602-8562 @
Bill,
Attached are copies of mer letters submitted with permit applications to the
Resource Agenaes for the Rancho Carlsbad Channel Maintenance project. This will
pFovide addtess information for )pow intended use.
Please let me know if you need further info.
Dick
5200 EL CAMINO REAL CARLSBAD. CA 92008-3899
August 27,2002
John H. Robertus
Executive Officer
CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD
9174 Sky Park Court, Suite 100
San Diego, CA 92123
RANCHO CARLSBAD MOBILE HOME PARK - AQUA HEDIONDA CREEK
MAINTENANCE (RECON NUMBER 3001B)
Dear Mr. Robertus:
Our community is most desirous of having our stream dredged as soon as possible.
Approximately 50% of Rancho Carlsbad is in the 100 year flood zone, and at present, the Aqu
Hedionda is seriously silted.
We have had four (4) winter seasons of low rainfall and as a result no threat of flooding. An
average “El Nino” year, however, would overflow OUT banks at this point, and a repeat of a
1997-98 rainfall year could cause serious damage, in our opinion.
We urge you to give this captioned request priority attention so that dredging can begin as soc
as possible and future dredging be done on a timely basis.
Thank you for your consideration.
Russ Kohl, President
Rancho Carlsbad Homeowner’s Association
CC: David Hauser, Deputy City Engineer
ADMINISTRATION
PHONE. .(760)438-0333
FAX: (760)438-1608 I I ____._-
RANCHO CARLSBAD MOBILE HOME PARK
PRELIMINARY ALTERNATIWCS ANALYSIS FOR
AGUA HEDIONDA CHANNEL MAINTENANCE
5-13182 C
Dennis C. Bowling, M.S.
RCE #
Prepared by:
Water Resources Division
Rick Engineering Company
5620 Friars Road,
San Diego, California 92 1 10
www.rickengineexing.com
(619) 291-0707
JANUARY 8,200d3
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TABLE OF CONTENTS
VOLUME 1 :,
Introduction ................................................................................................................................ 1
Vicinity Map ............................................................................................................................. .3
Hydrologic Analysis ................................................................................................................. 4
Table 1 : 100-year discharges (cfs) in Calavera Creek and Agua Hedionda
Creek Within the Rancho Carlsbad Mobile Home Park.. .............................................. ..6
Project Constraints ...................................................................................................................... 7
Hydraulic Analysis.. .................................................................................................................. 9
Table 2. Anticipated Detained 100-year WSELs for the
Agua Hedionda Creek Grading Alternatives .............................................................. 13
Table 3. Summary of Inundated Lots Resulting from Each
Agua Hedionda Creek Grading Alternative ................................................................. 13
Table 4. Estimated Dredge Volume for Agua Hedionda
Creek Grading Alternatives ................................... ..: ................................................. .14
Table 5. Approximate Depth of Excavation for Agua Hedionda
Creek Grading Alternatives ......................................................................................... 14
Maintenance Program .............................................................. .:.. ............................................ 15
Conclusion ............................................................................................................................... 16
Aerial Photographs
Map Pocket 1 : Preliminary Rancho Carlsbad Channel and Bash Project 100-Year Floodplain
Alternatives
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TABLE OF CONTENTS
VOLUME 2:
Appendix A:
Appendix B:
Appendix C:
Appendix D:
Appendix E:
Appendix F:
Appendix G:
1 00-Year Ultimate Detained HEC-1 Hydrologic Analysis (FN: BJBBJDF.HC1)
1 00-Year HEC- 1 Hydrologic Analysis with Additional Detention
(FN: DBTEST2.HCl)
HEC-2 Analysis of Existing Channel Geometry with Existing Hydrology and
Proposed Hydrology (FN: RCMAINEX.HC2)
HEC-2 Analysis of Alternative 1. Side-slopes (2: 1) extending to the Original
Design Flowline Elevation (FN: RCmF.HC2)
HEC-2 Analysis of Alternative 2. Side-slopes (3:l) extending to the Original
Design Flowline Elevation (FN: RC3T.HC2)
HEC-2 Analysis of Alternative 3. Side-slopes (2: 1) extending to the Existing
Ground Elevation at the El Camino Real Bridge (FN: RCPFBF.HC2)
HEC-2 Analysis of Alternative 4. Side-slopes (3:l) extending to the Existing
Ground Elevation at the El Camino Real Bridge (F": RC3TBF.HC2)
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01-08-03
INTRODUCTION
The purpose of this report is to summarize the design alternatives for Agua Hedionda Creek that have
been prepared by Rick Engineering Company for the City of Carlsbad as part of the Rancho Carlsbad
Channel and Basin Project. The Rancho Carlsbad Mobile Home Park (RCMHF) is an existing
residential area located north-east of El Camino Real, south-east of the proposed Cannon Road and
south-west of the proposed College Boulevard within the city of Carlsbad, California. RCMHP contains
portions of both Agua Hedionda and Calavera Creeks. Agua Hedionda Creek flows westerly through
the southern portion of RCMHP. Calavera Creek flows southwesterly along the northern property
boundary. Calavera Creek confluences with Agua Hedionda Creek within the RCMHP approximately
300 feet upstream of El Camino Real.
Original Channel Design
The original constructed Agua Hedionda Creek channel was an earthen trapezoidal channel, as shown
on the “Grading Plans for Rancho Carlsbad Mobile Home Park” dated June 27,1969 prepared by South
Bay Engineering. The overall length of the channel was approximately 1.2 miles and included both
Agua Hedionda Creek and Calavera Creek. The side slopes were 2: 1 (horizontakvertical) and the
approximate bed slopes were 0.15 and 0.30 percent in Agua Hedionda Creek and Calavera Creek,
respectively. The bottom width of Agua Hedionda Creek varied from 58 feet at the El Camino Real
Bridge to 44 feet upstream of the confluence. The approximate channel depth was 1 1.5 feet. The
bottom width and channel depth of Calavera Creek were 4 feet and 9 feet, respectively.
Sedimentation Pattern within Channel
Historically, Agua Hedionda Creek has been highly subject to sedimentation within the channel along
areas of the entire creek. Portions of the channel have experienced up to 6 feet or more of sediment
deposition within the Mobile Home Park. This high sediment load may be the result of large agricultural
areas upstream of the RCMHP as well as the effects of an increased peak discharge within Agua
Hedionda Creek due to development within the upstream watershed. Because of the increased peak
discharge and the accumulation of sediment in the channel over time, the capacity of Agua Hedionda
Creek to convey storm water through the RCMHP has diminished, and currently a large number of
properties within the Mobile Home Park are subject to inundation during a 1 00-year storm event.
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Calavera Creek has been subject to erosion within the upstream portion of the channel and
sedimentation within the downstream portion of the creek near the confluence with Agua Hedionda
Creek. As a result of the sedimentation and the encroachment of homeowners into the channel, Calaver,
Creek no longer has capacity for the 100-year storm event.
Proposed Channel Maintenance
In an effort to alleviate flooding within the Mobile Home Park, the City of Carlsbad has investigated
several alternatives to increase the capacity of the creeks and improve flood protection in the area. Rick
Engineering Company prepared a study entitled, “Rancho Carlsbad Channel and Basin Project,” dated
June 30,1998 that provided the preliminary design of four detention basins within the watershed
tributary to the RCMHP, determined the maintenance and sediment removal required to return Agua
Hedionda Channel and Calavera Creeks to their original design configurations per the 1969 Grading
Plans, and analyzed the effects of the reduced flow and increased channel capacity on the limits of
inundation within the Mobile Home Park.
Although the original Channel and Basin Project design called for maintenance of Calavera Creek as
well as Agua Hedionda Creek, environmental and biological concerns as well as constructability issues
determined that the maintenance of Calavera Creek was not practical. However, the maintenance of the
Agua Hedionda Creek will provide hydraulic improvement to Calavera Creek and increase the capacity
of the channel for flood protection.
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VICINITYMAP
RANCHO CARLSBAD MOBILE HOME PARK
CITY OF OCEANSIDE
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HYDROLOGIC ANALYSES
The U.S. Army Corps of Engineers HEC-1 computer program was used to prepare hydrologic models of
the watersheds tributary to Agua Hedionda Creek and Calavera Creek upstream of the Rancho Carlsbad
Mobile Home Park. The HEC-1 models analyze runoff from the ultimate development of the upstream
watershed and take into account the effects of the four proposed detention facilities. The detention
facilities are named Melrose, Faraday, BJB and BJ. These analyses were prepared for the “Rancho
Carlsbad Channel and Basin Project” report dated June 30, 1998. These HEC-1 analyses and have been
revised to model new watershed boundaries related to the drainage across proposed Cannon Road,
analysis of the split flow in Calavera Creek, and a new weir structure geometry at the outlet of detention
basin BJB. Discussion of these revisions is included below. The revised 1 00-year ultimate detained
condition HEC- 1 analysis for the Rancho Carlsbad Mobile Home Park is included in Appendix A.
Existing Drainage Pattern
The current FEMA model shows the flow in Calavera Creek splitting to the north and south sides of an
existing concrete wall that is located along Calavera Creek. The total effective FEMA flow in Calavera
Creek is 1350 cfs, which splits into a flow of 805 cfs on the north side of the existing wall and a flow of
545 cfs on the south side of the existing wall. The flow on the north side of the wall is routed to an
existing 8’x 8’ box culvert under El Camino Real.
Proposed Detention Facilities
The Calavera Hills and Robertson Ranch development projects are located within the watershed for
Calavera Creek, just north of the RCMHP. As these projects are developed, detention Basin BJB will be
constructed simultaneously with the construction of Cannon Road and College Boulevard. Due to the
restricted capacity of Calavera Creek, a portion of the flows discharging fkom detention basin BJB will
be conveyed within the Robertson Ranch project, nofi of the existing wall and south of Cannon Road,
to honor the existing drainage pattern and reduce the flows entering the Rancho Carlsbad Mobile Home
Park on the south side of the wall to approximately 1000 cfs. This will require “plugging” the holes
along the wall that currently convey flow north and south of the wall during large storm events. Based
on the final design of Detention Basin BJB, the anticipated 100-year outflow from Detention Basin BJB
is 1292 cfs. After 625 cfs of this outflow splits to the north side of the wall, the remaining flow is routed
to the south side of the wall and combines with the outflow from Detention Basin BJ. Based on the final
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design of Detention Basin BIB and the preliminary design of Detention Basin BJ, the total anticipated
flow in Calavera Creek on the south side of the wall is 10 17 cfs.
The mount of flow splitting to the north side of the existing wall is 625 cfs, which combines with
tributary watersheds and results in a total flow of 702 cfs at the downstream end of Calavera Creek on
the north side of the wall. The flow on the north side of the wall is routed through a triple 10’ x 4’ box
culvert under proposed Canon Road and ultimately to the existing 8’ x 8’ box culvert under El Camino
Real. The 100-year proposed flow of 702 cfs on the north side of the wall is lower than the effective
FEMA flow of 805 cfs. However, we prepared hydraulic analyses to determine if the existing 8’x 8’ box
culvert under El Cambo Real has enough capacity to pass the proposed 100-year flow.
a
The results show that the existing 8’x 8’ box culvert doesshave capacity for the 100-year flow, and
inundation over El Canino Real and proposed Canon Road is anticipated. In order to prevent inundation
over these road crossings, modification of the box culvert will be required with an 18’xlO’x5’ (WxHxL)
transition structure. However, this transition structure geometry will not provide any freeboard at El
Camino Real.
In order to allow for freeboard along El Camino Real, the 8’x 8’ box culvert under El Camino Real
7
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would need to be replaced with a larger culvert and further hydraulic analyses will be required.
Replacing the existing 8’x 8’ box culvert will also require authorization from governing agencies
regarding Coastal Permits.
fl -
Two detention basins are also proposed within the Agua Hedionda Creek watershed upstream of the
RCMHP, one at Faraday Avenue and one at Melrose Drive. The preliminary design for these detention
facilities is based on the revised HEC-1 analyses that are included in Appendix A of this report. Table 1
shows the results of the HEC-1 analyses tributary to the Mobile Home Park. These results are sybject to
change based on the final design of the BJ, Faraday, and Melrose detention basins.
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DCB:RCad/Report/l305 1 C.003.doc
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5
Table 1: 100-year discharges (cfs) in
Calavera Creek and Agua Hedionda Creek within the
Rancho Carlsbad Mobile Home Park
Existing Condition
City of Carlsbad Preliminary Ultimate
Ultimate Developed Developed Detained
* The 1998 report stated an ultimate detained flow of 7600 cfs in Agua Hedionda Creek, a flow of 1550 cfs in Calavera Creek, and 8970 cfs downstream of the confluence.
Additional Detention Facilities
Preliminary investigation of the feasibility for construction of a DSOD Jurisdictional dam upstream of
the MPH was prepared to estimate the storage volume required to provide flood protection within the
MHP. The construction of additional detention would minimize flooding in the MHP area without
aaintenance within Agua Hedionda Creek. The existing hydraulic capacity of the channel was
determined using the HEC-2 hydraulic program by modeling the existing topography in Agua Hedionda
Creek with a series of flows until the flow was contained within the channel through most of the MHP.
The HEC-2 analyses show that the existing capacity of Agua Hedionda is approximately 4000 cfs. In
order to reduce 100-year flows in Agua Hedionda Creek to approximately 4000 cfs, the detention basin
at,Faraday would requirrL- e-feet of storage volume, and an additional detention basin would need
to be constructed what would provide 895 acre-feet of storage volume. The additional HEC- 1 detention
analysis is included in Appendix B, along with a hydrology map showing the location of the proposed'
detention basins.
Prepared by:
Rick Engineering Company- Water Resources Division DCB:RC~dlReport/l3051 -C.003.d0~
01-08-03
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PROJECT CONSTWNTS
Additional factors affecting the limits of grading of this project have impacted the proposed Agua
Hedionda channel grading. These factors include, but are not limited to: the proximity to the Coastal
Zone, the presence of native and non-native trees along the channel banks, and the stability of the
channel banks.
Coastal Zone
The limits of the Coastal Zone are located at El Camino Real, and grading within the limits of the
Coastal Zone would require &ditional permits and coordination. - Therefore, grading downstream of El
Camino Real is nota practical alternative. Fecause the defined maximum limits of grading do not
extend underneath the El Camino Real Bridge, the proposed flowline of the channel may “ramp up” to
match the existing ground- elevations under the El Camino Real Bridge. This “ramp” would diminish
the conveyance of low flows through the channel, and .. increase the potential for ponded water just
upstream of the bridge. Therefore, the downstream conveyance of low flows is also a concern for the
channel design. Additional discussion of grading and drainage alternatives at the El Camino Real
Bridge are included in the following section of this report.
- - -
e ?
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Native and Non- Native Trees within the Channel
Also, the RCMHP Homeowners Association and the Environmental Resource Agencies have voiced
concerns regarding the removal of mature trees and native trees along the Agua Hedionda Creek Bank.
In order to preserve as many existing mature trees as possible within Agua Hedionda Creek, a biologist
was consulted to identify the native and exotic trees along the channel to determine what trees could be
removed during the proposed maintenance. The location of the trees specified to remain determined the
maximum limits of grading along Agua Hedionda Creek. Due to the location of these trees along the
channel side-slopes, the original channel bottom widths as shown on the “Grading Plans for Rancho
Carlsbad Mobile Home Park” dated June 27,1969 prepared by South Bay Engineering can not be
completely recovered. After the proposed grading is completed, re-vegetation will be required along the
banks of the channel.
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Aerial photographs of the RCMHP area that date back to 1973 are included in the Aerial Photographs
section in this report. The RCMHP homeowners association has stated that some maintenance has
occurred within the channel in the late seventies andlor early eighties.
4
Slope Stabilitv
Soil investigations are provided by GEOCON in a report entitled, “Limited Geotechnical Investigation,
Agua Hedionda Creek, Rancho Carlsbad, Carlsbad, California” dated September 5,2002, as well as an
Addendum letter dated October 7,2002. Based on the field investigations, the surface soils suggest that
the soils would require significant excavation, recompaction and reinforcement to provide slope stability
at 2:l (per the original 1969 design). This report suggested 3:l or 4:l side slopes would provide a more
stable channel configuration. These findings are based on surface investigation, and additional soils
investigations including borings within the channel would be required to determine if the originally
constructed 2: 1 banks have been adequately compacted to support a 2: 1 side slope during channel
maintenance. During final design of the maintenance project, erosion concerns in compliance with the
requests and recommendation of the Environmental Permitting Agencies Will need to be addressed, such
as optional riprap or plantable slope reinforcing fabric at the trees.
9
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a Due to the above mentioned factors, the original design configuration of Agua Hedionda Creek cannot
be completely recovered, several design alternatives have been proposed for the grading in Agua
Hedionda Creek that address the above-mentioned issues. The Hydraulic Analysis section of this report
includes detailed discussion and hydraulic analyses of five proposed design alternatives for Agua
Hedionda Creek.
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Rick Engineering Company - Water Resources Division 01 48-03
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HYDRAULIC ANALYSIS
Agua Hedionda Creek has historically been subject to sedimentation within the channel along areas of
the entire creek. Portions of the channel have experienced up to 6 feet or more of sediment deposition
within the Mobile Home Park. This high sediment load may be the result of large agricultural areas
upstream of the RCMHP as well as the effects of an increased peak discharge within Agua Hedionda
due to development Within the upstream watershed. Because of the inn- and the
accumulation of sedimeumnel over time, the capacity of Agua Hedionda Channel to convey - - storm water through the RCMHP has diminished, and currently a majority of the Mobile Home Park is
subject to inundation during a 100-year storm event. -
The U.S. Army Corps of Engineers HEC-2 computer program was used to determine the hydraulic
effects of the maintenance and sediment removal from Agua Hedionda Creek based on the ultimate
detained 100-year storm event.
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Additional Design Considerations
The following are a description of additional concerns associated with the maintenance in Agua
Hedionda Creek that have transpired since the June 1998 “Rancho Carlsbad Channel and Basin Project”
report.
Channel Vegetation
The existing condition hydraulic analyses of Agua Hedionda Creek that are discussed later in this report
show that velocities in the channel are up to approximately 15 feet-per-second during large storm events.
The high velocities as well as ongoing maint y the residents of the MHP have prevented
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significant establishment of mature vegetation within the main channel bed. The side slopes of the
channel have become vegetated with mostly ornamental and exotic species assumed to be planted by the
e-
residents of the Mobile Home Park. mefor e, maintenance of the Agua Hedionda Channel is expected -
---* to have little impact to environmentally sensitive habs. The hydraulic analysis of Agua Hedionda
Creek assumes that the channel will continue to be maintained regularly and the establishment of mature
vegetation within the channel will be prevented.
Convevance of Low Flows at the El Camino Real Bridge
due to the proximity ofthis
project to the Coastal Zone. The original Agua Hedionda channel design elevation at the El Camino
Real Bridge is 3 1.6 feet on the 1969 Grading Plans. Due to deposition in the channel, the accumulated
sediment at the El Camino Real Bridge has reached an elevation of 35.4 feet based on a field survey
dated June 2002. In order to match the existing ground at El Camino Real Bridge, the flowline of the
channel will “ramp up” a vertical distance of approximately 4 feet. This ramp will prevent low flows
from being conveyed through the channel, and will create a potential for ponded water just upstream of
the bridge. It is anticipated that a large storm event will transport the accumulated sediment under the El
Camino Real Bridge and provide drainage of the flows for future storms. However, it is difficult to
predict when a storm event adequate to remove the sediment will occur.
-
In order to prevent ponding water and the risk of vector breeding upstream of the El Camino Real
Bridge, a low-flow drainage pipe may be installed upstream of El Camino Real to route low flows from
Agua Hedionda Creek to the existing 8’ x 8’ box culvert under El Camino Real Road downstream of the
-----I.””,- --
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Robertson Ranch property. Another alternative involves the installation of a pump at the El Camino
Real Bridge to pump flows over the ramp and under the El Camino Real Bridge to the Lagoon.
Based on conversations with the San Diego Regional Water Quality Control Board (Regional Board)
both situations should be presented to the Regional Board in writing, requesting a written response from
the Board. The Regional Board may either require additional permitting for the project based on
increased impacts to jurisdictional waters, or determine that no additional permits are required and
handle any potential impacts through the 401 Water Quality Certification Process. A written response
from the Regional Board would alleviate the possibility of differing opinions among regulators and
identify a clear path to follow.
Alternatively, the existing ground elevation of 35.4 feet at the El Camino Real Bridge could be extended
as the constant flowline elevation of the proposed channel until it daylights with the existing drop
structure in Agua Hedionda Creek located just downstream of the Wood Plank Bridge. This alternative
does not provide as much increase to the capacity in Agua Hedionda Creek, but will maintain
conveyance of low flows through the channel without installation of a drainage pipe or pump upstream
of the El Carnino Real Bridge.
Kellv Ranch Weir Structure ? ~
According to the as-built improvement plans entitled, “Agua Hedionda Channel” revised November 13,
1985, there is an existing desilting basin located just downstream of the El Camino Real Bridge that
includes a weir structure located approximately 1300 feet downstream of the bridge. A field survey
performed June 2002 shows that the sediment elevations at the downstream face of the El Camino Real
Bridge are at least 6 feet higher than the design flowline elevation of this weir as shown on the
November 1985 improvement plans. The design elevation of the weir structure on the 1985
improvement plans is 23.5 feet. However, the sediment elevation modeled in the HEC-2 analyses at this
location is approximately 24.5 feet. Because the drop structure and the weir structure that are associated
with the desilting basin have been completely buried under existing sediment, they do not impact the
HEC-2 analyses of Agua Hedionda Creek.
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Existing Condition Analysis
The existing condition HEC-2 hydraulic analysis of Agua Hedionda Creek and Calavera Creek is
located in Appendix C of this report. The cross-sectional geometry is based on field surveys of Calavera
Creek in December 2001 and Agua Hedionda Creek in May 2002. The hydraulic analysis of the
existing topography in the channel includes a water surface profile based on the existing hydrology, as
well as a water surface profile based on the proposed detained hydrology that includes the construction
of Detention Basins BJB, BJ, Melrose, and Faraday as well as the split flow in Calavera Creek. The
map entitled, “Preliminary Rancho Carlsbad Channel and Basin Project 100-Year Floodplain
Alternatives” located in Map Pocket 1 shows the limits of flooding in the MHP associated with the
existing topography in Agua Hedionda for both the existing condition hydrology and the proposed
detained condition hydrology.
Proposed Maintenance Design Alternatives
The following is a summary of the design alternatives presented for the proposed maintenance of Agua
Hedionda Creek and the appendices in which the corresponding HEC-2 hydraulic analyses are located.
All of the following alternatives include the proposed ultimate detained flows in Agua Hedionda Creek
and Calavera Creek.
Alternative 1.
Alternative 2.
Alternative 3.
Alternative 4.
Alternative 5.
Trapezoidal channel with 2: 1 side-slopes extending fiom the field surveyed limits of
grading to the original design flowline elevation (Appendix D)
Trapezoidal Channel with 3: 1 side-slopes extending from the existing toe of slope to the
original design flowline elevation (Appendix E)
Trapezoidal channel with 2: 1 side-slopes extending from the field surveyed limits of
grading to the existing ground elevation at the El Camino Real Bridge (Appendix F)
Trapezoidal channel with 3 : 1 side-slopes extending fiom the existing toe of slope to the
existing ground elevation at the El Camino Real Bridge (Appendix G)
No Grading in Agua Hedionda Creek (Profile 2 of Existing Condition Analysis located
in Appendix C) -
.“.
The map entitled, “Preliminary Rancho Carlsbad Channel and Basin Project 100-Year Floodplain
Alternatives” located in Map Pocket 1 shows the HEC-2 cross-section locations, as well as the inundated
areas associated with each maintenance alternative. Table 2 shows the anticipated detained 1 00-year
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xsec ' Alternative 1 Alternative 2 IAlternhve 3 'Alternative 4 Alternative 5
2 44.41 43.68 43.65 44.04 44.63
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water surface elevations. Table 3 shows the anticipated number of inundated lots and the average depth
of water within the inundated areas for each of the five Agua Hedionda Creek grading design
alternatives.
44.99 44.1 I 45.66 45.55 46.27
Table 2. Anticipated Detained 100-year WSELs
for the Agua Hedionda Creek Grading Alternatives
3 1 45.52 I 45.27 I 46.55
i I Detained 100-vear WSEL. feet 3
46.91 47.42 ~
Number of
Inundated Lots
Average Depth
of Water, feet
Alternative 1 Alternative 2 Al ternative 3 Alt ernative 4 Alternative 5
102 111 148 173 236
0.9 0.8 1.65 2.1 2.6
Table 3. Summary of Inundated Lots Resulting
from Each Agua Hedionda Creek Grading Alternative
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CONCLUSION I
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Agua Hedionda Creek is highly subject to sedimentation for the majority of the creek. Portions of the
channel within the Mobile Home Park have experienced up to 6 feet or more of sediment deposition
since the original channel construction. This high sediment load may be the result of agricultural areas
upstream of the RCMHP as well as the effects of an increased peak discharge within Agua Hedionda
Creek due to development within the upstream watershed. Because of the increased peak discharge and
the accumulation of sediment in the channel over time, the capacity of Agua Hedionda Creek to convey
storm water through the RCMHP has diminished, and currently a significant portion of the lots within
the Mobile Home Park is subject to inundation during a 100-year storm event. In an effort to minimize
flooding witbin the Mobile Home Park, the City of Carlsbad has investigated several alternatives to
increase the capacity of the channel and improve flood protection in the area.
The design concerns for the maintenance of Agua Hedionda Creek include slope stability of the soil
material, removal of existing native trees along the channel side slopes, and downstream conveyance of
low flows due to the proximity of the project to the coastal zone. The following is a summary of the
design alternatives presented for the proposed maintenance of Agua Hedionda Creek. All of the
following alternatives include the proposed ultimate detained hydrologic conditions.
Alternative 1. Trapezoidal channel with 2: 1 side-slopes extending &om the field surveyed limits of
grading to the original design flowline elevation
Alternative 2. Trapezoidal Channel with 3:l side-slopes extending from the existing toe of slope to the
original design flowline elevation
Alternative 3. Trapezoidal channel with 2: 1 side-slopes extending from the field swveyed limits of
grading to the existing ground elevation at the El Carnino Real Bridge
Alternative 4. Trapezoidal channel with 3:l side-slopes extending from the existing toe of slope to the
existing ground elevation at the El Camino Real Bridge
No G-rading in Agua Hedionda Creek Alternative 5.
Each alternative was analyzed hydraulically to determine the number of lots removed fiom the
floodplain. The resulting water surface elevations were mapped, and the floodplain for each alternative
" __._ --
Prepared by:
Rick Engineering Company - Water Resources Division
16
DCB:RC:nd/Report/l3051-C.OO3.doc
01-08-03
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is shown on the map entitled, "Preliminary Rancho Carlsbad Channel and Basin Project 1 00-year
Floodplain Alternatives," dated December 2002 included in Map Pocket 1. a
111 This report summarizes the maintenance design alternatives for Agua Hedionda Creek. In order for
Rancho Carlsbad Channel and Basin Project to proceed into final design stages, the following issues
need to be resolved:
1. The soil stability within the channel and the need for additional geotechnical investigations
including borings within Agua Hedionda Creek.
2. The conveyance of low flows at the El Camino Real Bridge.
3. The environmental permitting through the San Diego Regional Water Quality Control Board,
the U.S. Army Corps of Engineers and The California Department of Fish and Game.
CI
I
I
1'
Prepared by: DCB:RC~d/Repod13051 C.003.doC
Rick Engineering Company- Water Resources Division 01-08-03
17
5200 EL CAMINO REAL = CARLSBAD, CA 92008-3899
March 20,2003
Mr. David Hauser
Deputy City Engineer
City of Carlsbad
1635 Faraday Avenue
Carlsbad, CA 92008
Re: Flood Control - Rancho Carlsbad
Dear Mr. Hauser:
The City of Carlsbad commissioned and accepted a flood control report entitled “Rancho
Carlsbad Channel & Basin Project” prepared by Rick Engineering Company, dated June 30,
1998.
In general terms, that report recommended the construction of four detention basins, two on the
Agua Hedionda Creek and two on the Calaveras Creek. All of them “designed to be outside
DSOD’s jurisdictional limits; i.e., less than 50 acre- feet of storage volume and less than 25 feet
high”. In addition, silt removal and regrading of the stream beds within the park was
recommended, lowering the stream beds to their original design with further improvements at the
lower end. The result was that all but 14 homes would be outside of the 100 year flood plain.
Since that he, three of the four detention basms have been approved for construcbon by City
Council as part of highway construction projects by developers. The fourth basin, Basin BJ, will
be part of the College Reach A Highway project, part of the Cant&, Holly Springs
Development now in the advanced plhg stages.
Work on our stream dredging started in February 2000 with a request from your office to
complete forms relative to the BJB Basin project, which included the necessary dredging as per
the 1998 Rick Engineering report. Nothing further occurred as far as we knew until after we
wrote on 8/29/01 pointing out the continued silting of the Agua Hedionda creek and the concern
we had should we experience another “El Nino” rainy season. That September, Dick Jacobs
Associates, your consultant, inspected our stream beds prior to recommending a course of action.
Dredging the Agua Hedionda creek did not present any major problem, we were told, but the
Calaveras creek dredging did. The result was a revision in the 1998 plan. No dredging would be
done on this creek. The amount of flow fkom the BJB Basin would be restricted and the excess
I, ADMINISTRATION
PHONE: (760)438-0333
FAX: (760)438-1808
conveyed within the Robertson Ranch project on the north side of ow existing wall. This is
detailed in a Rick Engineering report dated: January .. 8,2003.
In May, 2002, the City consulting team working on the Agua Hedionda creek dredging,
presented to the RCOA Board and 150 residents attending, prehmhary plans for the dredging,
including maps of the creek dredging through Rancho Carlsbad. Attending from the City were
Dick Jacobs, Consultant and head of team; David Hauser; Dennis Bowling, Rick Engineering
and Eric Munoz. The City submitted applications to appropriate agencies in the summer of
2002. In the Fall, 2002, Dick Jacobs notified us that the Army Corps of Engineers was holding
up the approval and had concerns about the application. In early March, 2003, we learned of a
new analysis report from Rick Engineering on the Agua Hedionda Channel maintenance, dated
January 8,2003.
This report entitled ‘’Preliminary Alternatives Analysis for Agua Hedionda Channel
Maintenance” addresses in detail several alternatives for dredging. This report starts out with the
statement on page 1 that because of increase in sediment and an increased peak discharge, the
capacity of the creek has been dimbished and currently a large number of homes are subject to
inundation during a 100 year storm event. This is a fact we as laymen concluded by the summer
of 2001 which prompted our letter.
In a detailed review of this report, it is replete with problems. On pages 4 & 5 it discusses the
split flow of the Calaveras Creek water both north & south of our wall. On the north side, this
water is to be convoyed under El Camino Real through an existing 8 X 8 box culvert
approximately 700’ north of the E.C.R. bridge. The report concludes, however, that the culvert
does not have the capacity to handle a 100 year flow. Replacement of that culvert will require
governing agency coastal permits.
On page 6 it discusses the feasibility of additional detention basins on the Agua Hedionda
including upgrading the Faraday basin to a Class C Dam, that would hold 200 acre-feet instead
of 49. An additional 895 acre-feet of retention would still be needed, however. We did not see
Appendix B, however, so we can’t comment further. On page 7, it states “the limits” of the
coastal zone are located at El Camino Real and any grading would require coastal zone permits,
and therefore, grading down stream of El Camino Real is not a ~ractical alternative! ! ! !
Furthermore, these “limits” do not extend under the E.C.R. bridge and any dredging done up
stream of the bridge down to the original design depth would create ponded water. On page 10 it
states that the design elevation at the bridge is 3 1.6 feet and due to accumulated sediment it is
now 35.4 feet. We understand that the 1998 Rick Engineering report used the designed elevation
of 31.6 feet. The report goes on to suggest alternative ways to minimize the ponding and vector
breeding.
This report also discusses the existence of a weir structure approximately 1300’ downstream from
the E.C.R. bridge that has been completely buried and that the sediment build up of the creek on
the downstream face of the E.C.R. bridge is 6’ higher than the design flow line stated in a 1985
plan. That observation was made in June, 2002.
3
This report then lists 5 alternative maintenance designs for the Agua Hedionda creek, assuming
all 4 basins are completed. Design alternate one still leaves 102 homes in the flood zone. The
inundated number increases through alternate '5, where 236 homes are affected. (See chart on
page 13.) This'result is unacceptable to this comm~ty, and we would think unacceptable to the
City. Considerable funds will be spent on this dredging to achieve an inadequate result.
It appears to us that in all of these recommendations, the one major flaw throughout, is the fiilure
to face what to us is the obvious solution, dredging and maintaining an open stream flow beyond
the El Camino bridge and if necessary all the way to open water in the lagoon.
Both reports seek to avoid having, on one hand, to deal with the State Dam Authorities and the
other with the Coastal Commission. This silting is only going to continue until all land in the
watershed is developed and all farming ceases. The city needs to face the only obvious solution
and get on with it. We have had 4 years of low rainfall and this year so far is average and has not
been a problem. But we are a disaster waiting to happen. No basins have been completed to
date, the split flow of the Calaveras Creek is still a plan with inadequate drainage on the north
side, and no dredging has been done. A 10 year rain would flood our streets. A 25 or 50 year
storm would flood many homes and based on the drainage map that accompanied the January
2003 report, over 3/4's of this community would be under water in a 100 year flood scenario.
This a major problem that needs a prompt action plan, funding, adequate staffing, State and
Federal Agency cooperation and perhaps political muscle to see it through. This Association will
cooperate in any way we can to achieve a satisfactory solution.
Sincerely,
Russ Kohl
President
CC: Bud Lewis, Mayor, City of Carlsbad
Ramona Fht~ila, Council Member
Matt Hall, Council Member
Ann Kulchin, Council Member
Mark Packard, Council Member
Sue Loftin, R.C.O.A. Counsel
Bob Ladwig, Consultant, R.C.O.A.
Bill Arnold
Chairman., Negotiating Commitee
5200 EL CAMINO REAL CARLSBAD, CA 92008.3899
May 12,2003
Mr. Ray Patchett
City Manager
City of Carlsbad
1200 Carlsbad Village Drive
Carlsbad, CA 92008
Re: Flood Control - Rancho Carlsbad
Dear Mr. Patchett:
r The purpose of this letter is, to familiarize you with the drainage and flood control problems that
effect our community. Our letter ofMarch 20,2003 addressed to Mr. David Hauser, Deputy
City Engineer (copy attached), we believe summarizes the background and the current conditions
which we as residents are concerned about.
Rancho Carlsbad consists of 504 homes, plus our various communi^ owned buildings. We are a
gated, age restricted commdty with 24 hour security. Many of ouf residents are elderly with
limited mobility. Needless to say, any serious flooding would have catastrophic consequences.
The Rick Engineering report, dated January 8,2003, and the accompanying flood map indicates
that in a 100 year storm today the water elevation would flood 3/4 of our park and the water
height at the low end where the Agua Hedionda and Calaveras Creeks converge would be nine
feet above ground level. Most homes have a living floor level of three feet above ground level.
Even a 10 year event would cause damage to many homes.
We urge that you read the January 8,2003 report, it's a real eye-opener. Dredging the Agua
Hedionda Creek down to the original design level of 3 1.6 feet above sea level was recommended
within our park. That is also the design level under the bridge at El Camino Real. The problem
is that there is 4 feet of silt under the bridge leaving only 7 feet of clearance remailling. The
bridge, we are told, cannot be touched because coastal zone permits are required. (See Page 7 of
the report). This is nonsensical. When would you dredge, at 6 feet, 8 feet, or do you let it plug
up? Dredging beyond the bridge is also necessary as our letter states.
The 1998 Rick Engineering report which is the basis for the present drainage plan removed all
but 14 homes from the 100 year flood plain. The revised January 8,2003 report has fi-om 102
ADMl NISTRATION
PHONE: (760)438-0333
FAX '760)438- 1808
homes to 176 homes, depending on what grading plan is selected, still in the flood zone, and
that’s after all four basins are in place for upstream detention.
Because of the involvement of jurisdictions beyond the City, i.e., the State owned land west of
the bridge and all the Regional, State and Federal Regularity Agencies, we believe City Council
needs to make a policy decision and direct staff to fin& a long term solution to this problem.
We have spoken to the Mayor on two occasions recently, and he is sympathetic to our plight.
We look to you as the City Manager to coordinate the various City Departments to draft a policy
decision for City Council’s review that will provide staff and funding to solve this problem.
Finally, we believe a public presentation by the City to our residents would be in order once you
have formulated your solution.
Thank you.
Yours truly,
Bill Arnold, Chairman I Negotiating Committee
Russ Kohl
President, RCOA
CC: Mayor Bud Lewis
Bob Ladwig, Consultant
Sue Loftin, RCOA Counsel
99
j- 4 - City of Carlsbad
July 1 I, 2003
Russ Kohl
President
Rancho Carlsbad Homeowner's Association
5200 El Camino Real
Carlsbad, CA 92008-3899
Although I have spoken on several occasions with you and/or Bill Arnold regarding the issues
raised in your letter to me dated March 20, 2003, I apologize for not having prepared an
official written response. I have been distracted with other pressing matters. In addition, I was
waiting for Council confirmation of the new fiscal year Capital Improvement Program (CIP)
budget and waiting for confirmation of a proposed change in the project management before
reporting out on the project status.
Now that we have entered into the new fiscal year, I am happy to report that we are
refocusing new energy and commitment into the channel dredging and improvement project.
Last month, Council approved the new fiscal year .CIP budget that freed the financial
resources to carry out the additional studies required to expand the scope of the project and
to gain resource agency approval. I also canceled the services of consulting project
manager, Mr. Richard Jacobs, and retained the services of a new project manager, Mr. Glen
Van Peski. Although Mr. Jacobs performed admirably in moving the project to it's current
stage, I believe that Mr. Van Peski will provide an increased level of energy and experience
that will help move the project on through to construction.
As y~u cnrrectIy noted It? yow !etter, the channel dredging 2nd improvement piajed as
currently proposed is not particularly workable or feasible. Due to the requirements imposed
by the resource agencies and other environmental restrictions, we must re-examine both the
basin wide and local channel improvement plans and revise the project scope accordingly.
This re-evaluation will include looking at the feasibility of extending the dredging downstream
of the RCMHP. In addition, we will also review the full range of project alternatives such as
increasing the capacity or number of upstream retention basins, removal of existing homes
within the floodplain, raising of the homes within the floodplain and/or increasing channel
capacity by widening or raising the adjacent berms (which may also require removal or
relocation of homes).
Even though the mix of alternatives include scenarios that are unpalatable to the
homeowners, they are absolutely necessary to satisfy the Army Corps of Engineers
permitting requirements. The Corps' decision to require an individual permit rather than our
initially requested nationwide permit elevates their environmental approval criteria from one
of project mitigation to one of project avoidance.
1635 Faraday Avenue - Carlsbad, CA 92008-7314 (760) 602-2720 FAX (760) 602-8562 @
Additionally, as part of the expanded studies we intend to prepare the detailed hydraulic
studies required to analyze the benefits, impacts’and potential channel designs for the
drainage remaining on the north side of the RCMHP wall. Based upon the issues raised in
your letter and my review of the current studies, I concluded that such analysis is needed to
properly establish the flood control solution for the RCMHP.
It is our intent to seek the most practicable and economical solution to the flood control
problem within the RCMHP regardless of whether it involves seeking additional permits from
either the Coastal Commission or the State Division of Safety of Dams. As you are well
aware, avoidance of such permits was one of fne design criteria initiaiiy estabiisned for this
project due to the potential for significant project cost and/or processing time increases.
However, due to the potential costs to overcome the environmental and permitting agency
requirements for the current design, eliminating these restrictions may result in a more
economical and/or desirable solution to the flood control problem.
Although we fully intend to investigate the options for dredging downstream of the El Camino
Real Bridge, it should be noted that obtaining agency approval may not be possible or may
incur such high mitigation expenses as to make any such option economically unfeasible.
I will be meeting sometime in the next two weeks with the new project manager, Mr. Van
Peski, to bring him up to speed on the project. We met briefly in the field yesterday to review
the channel downstream of the bridge and north of the RCMHP wall. Once he has been fully
briefed, I would like to set up a time where I can introduce him to you and Bill to go over your
concerns for the project. I’ll call sometime next week to set up a time that is convenient for
you. Aftewards, I’d like to give Glen a walking tour the channel.
If YOU have further questions or comments regarding this matter, please feel free to write or
give me a call at 602-2739.
Deputy City Engineer
C City Manager
Public Works Director
City Engineer
Bill Arnold
Glen Van Peski
Citi . e 0 e --
April 13, 2004
Rancho Carlsbad Owner’s Association
Attn: Russ Kohl, President
5200 El Camino Real
Carlsbad, CA 92008
Pian to Alleviate Flooding at Rancho Carlsbad Mobil Home Park
This letter was prepared to outline the work underway to alleviate flooding at Rancho Carlsbad,
for the purpose of informing HUD.
Parts of the Rancho Carlsbad Mobil Home Park are subject to inundation by the 100-year storm.
The City is implementing a work plan to alleviate this flooding. Rancho Carlsbad is located
within the Area B Planned Local Drainage Area (PLDA) established by the City to fund City
master planned drainage facilities located within the Agua Hedionda Lagoon drainage basin.
The City has appropriated $5,060,500 from the PLDA Area B fund specifically for projects to
alleviate flooding within the Rancho Carlsbad Mobil Home Park. The five major drainage
projects associated with reducing flooding impacts to Rancho Carlsbad and their current status
are:
. . .
Flood Control Basin BJB (College/Cannon) - Completed
Flood Control Basin BJ (RCMHP RV Site) - Spring 2005*
Faraday/Melrose Flood Control Basins - Spring 2005*
Agua Hedionda Creek Dredging - Summer 2006
Calavera Creek Channel Improvement (north side of wall) - Summer 2006*
* Schedule is developer dependent
Several of the projects will be constructed by developers concurrent with adjacent development
projects, and precise timing is not known. The City is currently working on the preliminary
design for the Agua Hedionda Creek channel dredging. Environmental processing for the
dredging project should be commencing this year.
If you have any specific questions, please contact our Consultant Project Manager Glen Van
Peski at 760-720-0500 or gvanpeski@adelphia.net.
Respectfully,
David Hauser
Deputy City Engineer
Planning and Programs
C Glen Van Peski
RANCHO CARLSBAD MOBILE HOME PARK
ALTERNATIVE ANALYSIS FOR
AGUA HEDIONDA CHANNEL MAINTENANCE
Job Number 13182-D
RCE #32838, Exp. 0-
Prepared For:
City of Carlsbad
David Hauser 'i 1635 Faraday Ave I
Carlsbad, CA 92008
Prepared by:
Water Resources Division
Rick Engineering Company
5620 Friars Road,
San Diego, California 92 1 10
www.rickengineering .corn
(6 1 9) 29 1-0707
December 13,2004
TABLE OF CONTENTS
Introduction ...................................................................................................................,............. 1
Exhibit 1. Rancho Carlsbad Mobile Home Park Vicinity Map ...................................... 4
Exhibit 2. Agua Hedionda Basin Flood Control Projects ............................................... 5
Exhibit 3. Agua Hedionda Creek and Calavera Creek Watershed Map ......................... 6
Exhibit 4. Flood Insurance Rate Map (FIRM) ................................................................ 7
Hydrologic Analysis ....................................................................................... ........................... 8
Table 1 : Description of Detention Basins ..................................................................... 10
Table 2: 1 00-year Discharges in Calavera Creek and Agua Hedionda
Creek within the Rancho Carlsbad Mobile Home Park .................................. 13
Project Constraints .................................................................................................................... 14
Hydraulic Analysis ....... .. .. .. . ... .... .. .. . . . . . . . . .... .. .. . . . . . . .. . .... . . . .. . . . .. .... . . . . . .. . . . .... . ... .. . . ... . . . . .. . . ....... .... .. 16
Table 3. Anticipated Detained 100-year WSELs for the Agua Hedionda Creek
Grading Alternatives and Number of Inundated Lots .................................... 21
Ehbit 5. Alternative A Approximate Limits of Grading ..........................................., 22
Exhibit 6. Alternative B Approxir;nate Limits of Grading ............................................ 23
Exhibit 7. Alternative C Approximate Limits of Grading ......................... ................... 24
Ongoing Maintenance Program ....... .. . . . .. . . . . . .. . .. . .. . . .. . .... . . .. . . . . . . ,.. . . .. ... . ... . . . . . .. ... ... . . .... . . .. .. . . ....... . .27
Conclusion ...... .. . . . . . .. . . ... . . . .... ... . . ... .. .. . . . , . . . . . . . . . . . .. . . .. . . .. . . . .. . .. .. . .... ... . . . . . . . .. . .... .. . .. .. . . . . . . . . .. .. .. .. ... . . . . . .28
Table 4. Matrix Summary of Proposed Agua Hedionda Creek ( Maintenance Alternatives .... ........................................................... ............... 29
APPENDICES (on CD)
Appendix A: Referenced Plans
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“Grading Plan Rancho Carlsbad Mobile Home Park,” June 27,1969,
South Bay Engineering
“Capnon Road Bridge Over Agua Hedionda General Plan,” sheet 59 of
13 1, February 19,1998, McDaniel Engineering (Drawing No. 333-26)
“El Camino Real Bridge Widen Over Agua Hedionda Channel General
Plan,” sheet 68 of 13 1, February 19, 1998, McDaniel Engineering
(Drawing No. 333-2G)
“Lake Calavera Remedial Improvements General Site Plan,” sheet 6 of 3 5,
“Lake Calavera Remedial Improvements Civil Site Plan 1 ,” sheet 7 of 39,
“Lake Calavera Remedial Improvements Concrete Spillway Sections,”
sheet 10 of 39, “Lake Calavera Remedial Improvements New Outlet Pipe
Section,” sheet 24 of 3 5, October 2003, CGvL Engineers (Drawing No.
41 1-6)
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Prcpared by: Rick Engineaing Company - Water Resources Division DCB:KH:jf/Report/l3 182-D.002
12-1 3-04
.
Appendix B:
Appendix C:
Appendix D:
I Appendix E:
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I Appendix F:
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Appendix G:
Grading Plans for Melrose Detention Basin Outlet: “Palomar Fonun
Melrose Drive” sheet 11 of 17, June 3,2004, O’Day Consultants (Drawing
No. 399-4A)
Grading Plans for Faraday Detention Basin Outlet: “Carlsbad Oaks North
Faraday Ave,” sheet 20 of 37, February 2003, O’Day Consultants
(Drawing No. 41 5-9C)
Grading Plans for Detention Basin BJB: “Calavera Hills Phase 11,” sheet 5
of 80, October 22,2002, O’Day Consultants (Drawing No. 390-9A)
Grading Plans for Detention Basin BJ: Base Map “City of Carlsbad
Orthophoto Mapping,” sheet 55 of 225, Copyright 1991 (Drawing No.
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296-5)
Back-up Hydraulic Calculations
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Detention Basin Outlet Structure at Melrose
Detention Basin Outlet Structure at Faraday
Detention Basin Outlet Structure at BJB
Capacity of 8x8 RCB at El Camino Real
Hydrologic Analyses
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100-Year Ultimate Detained HEC-1 (FN: RC100.HCl)
100-Year Ultimate Undetained HEC-1 (FN: RCUNDET.HC1)
1 00-Year, 24-Hour Precipitation Map
HEC-1 Workmap with USGS Topographic Map
HEC-RAS Analysis of No Action Alternative (Executable Files: Project -
RanchoCar1sbadAH.prj; Plan - RanchoCarlsbadAH.pO1; Geometry -
RanchoCarlsbadAH.gO1 ; Steady Flow - RanchoCarlsbadAH.fD4)
HEC-RAS Analysis of Existing Detained Alternative
(Executable Files: Project - RanchoCar1sbadAH.pj; Plan -
RanchoCarlsbadAH.pO7; Geometry - RanchoCwlsbadAH.gO8; Steady Flow -
RanchoCarlsbadAH.fl)l) 1
HEC-RAS Analysis of Alternative A
(Executable Files: Project - RanchoCar1sbadAH.prj; Plan -
RanchoCarlsbadAH.pO2; Geometry - RanchoCarlsbadAH.g2 1 ; Steady Flow -
RanchoC arlsbadAH . fO 1 )
HEC-US Analysis of Alternative B
(Executable Files: Project - RanchoCarlsbadAH.prj; Plan -
RanchoCarlsbadAH.p24; Geometry - RanchoCarlsbadAH.g23; Steady Flow -
RanchoCarlsbadAH. fO 1)
Prepared by:
Rick Engineering Company - Water Resowes Division
DCB:KH:jf/Report/l3 182-D.002 12-13-04
I
Appendix H: HEC-IUS Analysis of Alternative C
(Executable Files: Project - RanchoCar1sbadAH.prj; Plan -
RanchoCarlsbadAH.p27; Geometry - RanchoCarlsbadAH.g26; Steady Flow -
RanchoCarlsbadAH.fO1)
MAP POCKETS
Map Pocket 1:
Preliminary Rancho Carlsbad Channel and Basin Project 1 00-Year Floodplain
Alternatives
Map Pocket 2:
HEC-RAS Workmap (Available on Request)
Prepared by: Rick Engineering Company - Water Resources Division DCB:KH:jfReport/l3 182-D.002 12-13-04
INTRODUCTION
Th- purpose of this report is to summarize the design alternati es for Agua Hedionda Creek that
have been prepared by Rick Engineering Company for the City of Carlsbad as part of the Rancho
Carlsbad Channel and Basin Project. The Rancho Carlsbad Mobile Home Park (RCMHP) is an
existing residential area located north-east of El Camino Real, south-east of Cannon Road and
south-west of College Boulevard Reach ‘A,’ within the City of Carlsbad, California (see Exhibit
1 on page 4).
RCMHF contains portions of both Agua Hedionda and Calavera Creeks. Agua Hedionda Creek
flows westerly through the southern portion of RCMHP. Calavera Creek flows southwesterly
along the northern property boundary. The confluence of Calavera Creek with Agua Hedionda
Creek within the RCMHP is located approximately 300 feet upstream of El Camino Real. The
Agua Hedionda Creek and Calavera Creek watersheds are shown on Exhibit 3 (page 6).
Original Channel Desien
The original constructed Agua Hedionda Creek channel was an earthen trapezoidal channel, as
shown on the “Grading Plans for Rancho Carlsbad Mobile Home Park” dated June 27, 1969
prepired by South Bay Engineering (Appendix A). The overall length of the channel was
approximately 1.2 miles and included both Agua Hedionda Creek and Calavera Creek. The side
slopes were 2:l (horizontal:vertical) and the approximate average bed slopes were 0.15 and 0.30
percent in Agua Hedionda Creek and Calavera Creek, respectively. The bottom width of Agua
Hedionda Creek varied &om 58 feet at the El Camino Real Bridge to 44 feet upstream of the
confluence. The approximate channel depth was 1 1.5 feet. The bottom width and channel depth
of Calavera Creek were 4 feet and 9 feet, respectively.
1
Sedimentation Pattern within the Channels
Historically, Agua Hedionda Creek has been highly subject to sedimentation within the channel
along areas of the entire creek. Portions of the channel have experienced up to 6 feet or more of
sediment deposition within the Mobile Home Park. This high sediment load may be the result of
large agricultural areas upstream of the RCMHP as well as the effects of an increased peak
discharge within Agua Hedionda Creek due to development within the upstream watershed.
Prepared by: Rick Engineering Company - Water R&urces Division 1 DCB:KH.jflRReportll3182-D.002
12-13-04
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Because of the increased peak discharge and the accumulation of sediment in the channel over
time, the capacity of Agua Hedionda Creek to convey storm water through the RCMHP has
diminished, and currently a large number of properties within the Mobile Home Park are subject
to inundation during a 1 00-year storm event.
Calavera Creek has been subject to erosion within the upstream portion of the channel and
sedimentation within the downstream portion of the creek near the confluence with Agua
Hedionda Creek. As a result of the sedimentation and the encroachment of homeowners into the
channel, Calavera Creek no longer has capacity for the 1 00-year storm event.
Proposed Channel Maintenance
In an effort to alleviate flooding within the Mobile Home Park, the City of Carlsbad has
investigated several alternatives to increase the capacity of the creeks and improve flood
protection in the area. Rick Engineering Company prepared a study entitled, “Rancho Carlsbad
Channel and Basin Project,” dated June 30, 1998 that provided the preliminary design of four
detention basins within the watershed tributary to the RCMHP, determined the maintenance and
sediment removal required to return Agua Hedionda and Calavera Creeks to their original design
configurations per the 1969 Grading Plans, and analyzed the effects of the reduced flow and
restored channel capacity on the limits of inundation within the Mobile Home Park.
Since the 1998 study, further modifications to the proposed maintenance improvements were
required. These modifications include updates to the hydrologic model, exclusion of Calavera
Creek from maintenance and grading activities, the analysis addi%nal alternatives, as well as
final design plans and calculations of three of the four proposed detention basins. The “Project
Constraints” section of this report addresses in detail the background of the required
modifications.
The existing Calavera Creek channel configuration results in split flow, with some flow being
conveyed north of the wall along the RCMHP as shown on Exhibit 4, the Flood Insurance Rate
Map (FIRM) panel number 06073C0768 F dated June 19, 1997 (page 7). The original Channel
and Basin Project design called for maintenance of Calavera Creek (i.e. widening the creek),
which would force all of the flow into Calavera Creek thereby eliminating the split flow to the
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north side of the wall. Environmental and biological constraints called into question the
practicality of the previously proposed maintenance and grading within Calavera Creek. Other
constraints include the encroachment of homeowners into Calavera Creek, which introduces
constructability issues of any grading along the channel banks. Preserving the current capacity of
Calavera Creek though maintaining the split flow situation to convey the 100-year storm can
avert maintenance within Calavera Creek. The proposed split flow scenario presented in this
report requires less flow be diverted to the north side of the wall than the existing FEMA-
mapped condition.
The maintenance of Agua Hedionda Creek in conjunction with the construction of the proposed
detention basins will provide hydraulic benefits to Calavera Creek and increase the capacity of
the channel for flood protection. This report presents several alternatives for maintenance of
Agua Hedionda Creek to restore flood protection within the RCM". Some alternatives require
grading south of El Camino Real, which was not proposed in the 1998 study, The locations of
the proposed flood control projects discussed in this report are shown on Exhibit 2 on page 5.
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HYDROLOGIC ANALYSES
The U.S. Army Corps of Engineers Hydrologic Engineering Center HEC-1 computer program
was used to prepare hydrologic models of the watersheds tributary to Agua Hedionda Creek and
Calavera Creek upstream of the Rancho Carlsbad Mobile Home Park. The hydrology was used
to determine preliminary detention basin sizes and outlet structures for four proposed detention
basins upstream of the Rancho Carlsbad Mobile Home Park two within Agua Hedionda Creek,
one at Melrose Drive and one at Faraday; and two within Calavera Creek, Basins BJ and BJB,
near the intersection of the Cannon Road and College Boulevard extensions. The hydrology was
also used as a source in the HEC-RAS hydraulic analyses.
Since the publication of the 1998 study there have been several modifications to the hydrologic
analysis of the watershed related to the hydrologic modeling parameters, Calavera Dam, and
final design of three of the proposed detention basins.
Hvdrolodc Modeline Parameters
One aspect of the hydrologic modeling parameters that has been modified since the initial study
was the channel Manning’s “n’’ and basin factor values used to calculate the lag time for each
watershed. Since the hydrology is based on the ultimate development of the watershed, the
Manning’s “n” and basin factor values were originally based on a typical developed condition for
the land-use type dominant in each watershed. However, based on current California State
Water Resources Control Board requirements for new developments, the tendency is less directly
connected impervious surfaces, resulting in a higher Manning’s “n” and higher‘basin factors due
to more natural channels. Therefore, the hydrologic model was updated to reflect this change.
4.
Calavera Dam
The City of Carlsbad has recently initiated a project involving the restoration and reconstruction
of the outlet strbcture for Calavera Dam. The modifications include replacing the existing outlet
tower, which currently does not function, with a new one. The new outlet tower will allow the
lake to be drawn-down in anticipation of large storm events, resulting in a lower peak flow out of
Calavera Lake, which has resulted in a change in the hydrology upstream of detention basin BJB.
The project is currently scheduled to go to bid in the Spring/Summer 2005. The hydrologic
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model was updated based on the following assumptions to reflect the impacts of drawdown of
Calavera Dam on the peak discharge in Calavera Creek.
0 Lake elevation is at 209’ (the crest of the outlet tower) when the storm begins
0 The 3 valves are opened once the storm starts
0 Valve geometry can be found on sheet 24 on the improvement plans prepared by CGvL
Engineers titled “Lake Calavera Remedial Improvements” (Drawing #: 41 1-6, dated
October 2003, Appendix A)
Spillway elevation is at 214.5’ per sheet 6 of the aforementioned plans 0
These analyses result in a 1 00-year peak flow into Lake Calavera of 1,83 1 cubic feet per second
(cfs) and a peak flow out of Calavera Dam of 967 cfs with a maximum ponded water Surface
elevation (WSEL) of 219.2’.
Detention Basin Design
The goal of the detention basins proposed by the 1998 study is to detain less than 50 acre-feet of
volume, to avoid being within the jurisdiction of the California Department of Water Resources
Division of Safety of Dams (DSOD). The modifications to the hydrology, as well as the analysis
of the final basin grading, has resulted in some changes to the outlet structure geomepjes.
Three of the four proposed detention basin outlet structures have been designed. The Melrose
detention basin outlet design prepared by O’Day Consultants (Drawing #: 399-4A, dated June 3,
2004) has been signed and approved by the City of Carlsbad. The Faraday detention basin outlet
design prepared by O’Day Consultants (Drawing #: 415-9C, dated February 2003) has also been
approved. Based on the modifications to the hydrologic modeling parameters and the Calavera
Dam outlet, as well as the final design information provided by the City of Carlsbad for the
Faraday and Melrose basin grading, the detention basin routing has been updated. Copies of the
plans are included in Appendix A for reference and copies of the hydraulic calculations
(prepared by Rick Engineering Company) for the outlet structures are included in Appendix B.
The construction of detention basin BJB was completed with the construction of the College
Boulevard and Cannon Road extensions per the plans prepared by O’Day Consultants dated
October 22,2002 (Drawing #:390-9A sheet 5 of 80, Appendix A). However, the outlet structure
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for detention basin BJB will ultimately require modifications to further ’reduce flows once the
Calavera Dam improvements are constructed to maximize the flood control benefit of Basin
BJB. Copies of the hydraulic calculations (prepared by Rick Engineering Company) for the BJB
outlet structure are included in Appendix B.
Location of QlOO Max. Max. Max. Storage
Detention (cfs) ponded Inundation Volume Outlet Structure Details
Basin WSEL Area(ac) (ac-ft)
(feet)
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Melrose 839 489 330.5 6.8 44.2 Box culvert with a rectangular orifice 5.6’
Faraday 906 642 241.4 6.8 49.8 Box culvert 4.3’ wide x 3.7’ tall (FL @
wide x 4’ tall (FL @ 308.0’)
221.8’)
75.16 2.4 49.9 72” RCP (FL @ 65.0’) and a rectangular
BJB* 1094 901 box culvert 1 1’ wide x 7’ tall with a 10’ wide
x 7’ tall square-edged entrance (FL @ I: 62.0’) *
I (FL @/ 62’) * BJ * 629 348 75.9 8 48 Rectangular box culvert 6’ wide x 3’ tall
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Detention basin BJ is still modeled based on the preliminary design outlined in the 1998 report.
The preliminary plans are based on the map titled “City of Carlsbad Orthophoto Mapping” sheet
55 of 225, Copyright 1991 (Appendix A).
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Table 1 provides a detailed summary of the detention basins.
I FEMA Drainape Patterns
The current effective Federal Emergency Management Agency (FEMA) study for Calavera
Creek shown on the FIRM Panel number 06073C0768 F, dated June 19,1997 (page 7) shows the
flow splitting to the north and south sides of the existing concrete wall that is located along the
creek. Per the FEW Flood Insurance Study (FIS), the total flow in Calavera Creek is 1350 cfs.
The FEMA models show approximately 805 cfs conveyed through Calavera Creek on the north
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side of the existing wall, and 545 cfs conveyed on the south side of the wall within the Calavera
Creek Channel in the RCMHP.
Modified Drainape Patterns
The analysis in the 1998 report assumed the entire flow fi-om Calavera Creek would be conveyed
through the RO because the flow would be concentrated fi-om Basin BJB and the channel
would be graded to increase capacity (i.e. flow would not split to the north side of the wall).
However, the project approach to Calavera Creek was modified since the initial study for several
reasons. The majority of property owners adjacent to Calavera Creek have encroached into the
creek with the construction of decks, patios, retaining walls, and landscaping. Any grading
activities within the channel would result in the removal of the structures which will not be
acceptable to many of the RCMHP residents. Also, preliminary biological investigations of
Calavera Creek identified mature oaks and willows established within the channel. The removal
of these mature trees would require extensive mitigation. If the trees were attempted to be
preserved by relocation or structural measures (e.g. retaining walls, etc.), the engineering and
construction costs would be extremely high and the survival rate of the trees is unknown.
Because the Calavera Creek channel does not have capacity for the entire flow in its chat
condition, a split flow scenario that more closely mimics the current FEMA model was created
by the construction of a weir near the outlet of detention basin BJB at the entrance to Calavera
Creek. The proposed split flow will result in the conveyance of approximately 500 cfs along the
north side of the wall adjacent to the RCMHP and Calavera Creek. This flow will be conveyed
under Cannon Road through triple 10’ wide x 7’ tall reinforced concrete boxes (RCB), under El
Camino Real through an existing 8’ x 8’ RCB, and combine with Agua Hedionda Creek
upstream of the Cannon Road Bridge prior to discharging into Agua Hedionda Lagoon.
The 8’ x 8’ RCB beneath El Camino Real is a restriction of the amount of flow that can split to
the north side of the wall at the weir. If too much flow splits to the north, flow will overtop El
Camino Real at a low point in the road (elevation = 41.3’) just upstream of the 8’ x 8’ RCB. The
peak discharge to be conveyed north of the wall was determined based on the capacity of the
existing 8’ x 8’ box assuming 500 cfs is diverted to the north side of the wall. Calculations
included the preparation of a HEC-2 hydraulic model for the north side of the wall extending
fkom the weir to the downstream face of the 8’ x 8’ box and a WSPGN hydraulic model of the 8’
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x 8’ box. The following flow rates from the HEC-1 were input into the HEC-2: 500 cfs at the
weir, 522 cfs at the Cannon Road triple RCBs, and 568 cfs at the 8’ x 8’ RCB. Based on results
fkom the HEC-2 the WSEL at the location of the low point in El Camino Real was 39.6,’ which
results in 1.7’ of freeboard. The HEC-2-calculated WSEL at the upstream face of the 8’ x 8’
RCB waq compared to the WSPGN-calculated WSEL at the same location for verification.
Copies of the WSPGN, HEC-2, and HEC-2 workmap are included in Appendix B.
It should be noted that due to environmental considerations fkom the resource agencies, frequent
storm flows fkom detention basin BJB that result in a peak discharge of less than approximately
300 cfs will be conveyed in Calavera Creek without flow splitting to the north side of the wall.
Any modifications to the split flow or the drainage patterns on the north side of the wall should
be designed to maintain this scenario, and not intercept any portion of flows less than
approximately 300 cfs to preserve the downstream habitat.
The drainage basin modeling in the HEC- 1 has been modified since the preparation of the 1998
study to reflect the split flow scenario. Refer to Appendix C for HEC-1 hydrologic calculations.
Table 2 shows a comparison of the 1998 study hydrologic results to those of the current 2004
study.
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Location
8050 7600
Calavera Creek
upstream of the
Mobile Home Park
Calavera Creek north
of the wall (within
Robertson Ranch)
Calavera Creek upstream of the
confluence with Agua Hedionda Creek
Agua Hedionda Creek upstream ofthe
confluence with Calavera Creek
Agua Hedionda Creek
downstream of the
confluence with
Table 2: 100-year Discharges in
Calavera Creek and Agua Hedionda Creek within the
Rancho Carlsbad Mobile Home Park
Condition
1350 I 1910 1550
NIA
8080 9950 8970
2004 Updated Hydrology
Undetained Detained
Hydrology Hydrology
1419 1 749 1
I 500 I
7795 I 7338 I
9195 1 8092 I Calavera Creek
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PROJECT CONSTRAINTS E
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Additional factors affecting the limits of grading of this project have impacted the proposed
Agua Hedionda channel grading. These factors include, but are not limited to: the proximity of
the project to the Coastal Zone, the presence of native and non-native trees along the channel
banks, environmental processing requirements, and channel vegetation.
Coastal Zone
The limits of the Coastal Zone are located along El Camino Real in the vicinity of this project.
Any maintenance alternative proposing to grade between El Camino Real and Cannon Road
would require additional permits and coordination with the Coastal Commission. This area is
within the Local Coastal Zone administered by the City Council. The Coastal Commission could
appeal any decision to allow grading or maintenance within the proposed channel downstream of
El Camino Real.
Native and Non Native Trees within the Channel
The RCMHP Homeowners Association and the Environmental Resource Agencies have voiced
concerns regarding the removal of mature trees and native trees along the Agua Hedionda Creek
bank. In order to preserve as many existing mature trees as possible within Agua Hedionda
Creek, a site visit was conducted with representatives fiom Rick Engineering Cornpa@,
RECON, RCMHP, and the City of Carlsbad in the spring of 2002 to identify the native and
exotic trees along the channel to determine what trees located on the channel banks could be
preserved during the proposed maintenance. Survey data was also collected to assist in
determining the maximum limits of grading along Agua Hedionda Creek. Due to the location of
these trees along the channel side-slopes, the original channel bottom widths as shown on the
“Grading Plans for Rancho Carlsbad Mobile Home Park” dated June 27, 1969 prepared by South
Bay Engineering can not be completely restored.
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The Agua Hedionda Creek maintenance project involves activities within a jurisdictional water.
Therefore, this project would require processing through the California State Water Resources
Control Board, the U.S. Army Corps of Engineers, as well as the California Department of Fish
and Game. The detention basins proposed at Melrose, Faraday, BJB, and BJ are subject to
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separate processing though the resource agencies as part of their associated development
projects since their construction is linked to the construction of adjacent developments, not to the
maintenance of Agua Hedionda Creek channel.
Channel Vegetation
The existing condition hydraulic analyses of Agua Hedionda Creek that are discussed later in this
report show high velocities throughout the creek especially at bridge crossings during large
storm events. The high velocities as well as ongoing maintenance by the residents of the
RCMHP have prevented significant establishment of mature vegetation within the main channel
bed of Agua Hedionda Creek upstream of El Camino Real. The side slopes of the channel have
become vegetated with mostly ornamental and exotic species presumably planted by the
residents of the Mobile Home Park. Therefore, maintenance of the Agua Hedionda Channel
within RCMHP is expected to have little impact to environmentally sensitive habitat. The
hydraulic analysis of Agua Hedionda Creek assumes that the channel will continue to be
maintained regularly and the establishment of mature vegetation within the channel will be
\ prevented. >
Due to the above-mentioned factors, the original design configuration of Agua Hedionda Creek
cannot be completely restored. Several design alternatives have been proposed for the grading in
Agua Hedionda Creek that address the project constraints. The Hydraulic Analysis section of
this report includes detailed discussion and hydraulic analyses of three proposed design
alternatives for maintenance of Agua Hedionda Creek.
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HYDRAULIC ANALYSIS
The U.S. Army Corps of Engineers Hydrologic Engineering Center HEC-RAS computer
program was used to determine the hydraulic effects of the maintenance and sediment removal
fiom Agua Hedionda Creek based on the ultimate detained 100-year storm event.
The existing condition cross-sectional geometry is based on field surveys of Calavera Creek in
December 2001 and Agua Hedionda Creek in May 2002. Updated cross-sectional geometry
downstream of Cannon Road is based on field surveys in June 2004. The following
improvement plans were used to model the Cannon Road Bridge crossing and El Camino Real
Bridge crossing, respectively: “Cannon Road Bridge Over Agua Hedionda General Plan,” sheet
59 of 131, and “El Camino Real Bridge Widen Over Agua Hedionda Channel General Plan,”
sheet 68 of 139, prepared by McDaniel Engineering (Drawing No 333-26). Copies of these
improvement plans are included in Appendix A.
Description of Alternatives
Several alternatives for maintenance of the Agua Hedionda Creek channel within the Rancho
Carlsbad Mobile Home Park have been investigated since 1998. There are environmental and/or
community impacts within Calavera Creek and Agua Hedionda Creek that may render
maintenance within portions of the channels undesirable. However, maintenance of the Agua
Hedionda Creek channel is imperative to improving conveyance and reducing flooding in the
RCMHP. The proposed alternatives for Agua Hedionda channel maintenance are described
below. Exhibits 5, 6, and 7 show the approximate limits of grading for Alternatives A, B, and C,
respectively. A schematic of the cross-sectional geometry for Alternatives A, B, and C as well as
the 1 00-year floodplain limits are shown on the floodplain alternatives map in Map Pocket 1.
The HEC-R4S workmaps are located in Map Pocket 2.
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No Action Alternative
The No Action Alternative models the current channel topography within the RCMHP
and models the conveyance of the 1 00-year undetained ultimate development hydrology.
This alternative proposes no changes to the existing drainage patterns and is presented to
reflect the current flooding potential within the RCMHP if no channel maintenance
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occurs and if none of the 4 proposed detention basins were constructed, and no
improvements were made to the Lake Calavera outlet structure. See Appendix D for the
No Action Alternative HEC-US model.
Existing Condition Detained Alternative
The Existing Condition Detained Alternative models the current channel topography
within the RCMHP and models the conveyance of the 100-year detained ultimate
development hydrology. This alternative is presented to reflect the potential flooding
within the RCMHP if no channel maintenance occurs, but assumes the 4 proposed
detention basins, Melrose, Faraday, BJB and BJ, are constructed, Calavera Dam
improvements are complete, the subsequent modifications to the BJB outlet structures
have been constructed, and 500-cfs is conveyed on the north side of the wall. See
Appendix E for the Existing Condition Detained Alternative HEC-RAS model.
Alternative A
Alternative A models the current channel topography within Calavera Creek, and models
the maintenance of approximately 2,500 feet of Agua Hedionda Creek between El
Camino Real and just downstream of Rancho Carlsbad Drive. Alternative A models the
conveyance of the 1 00-year detained ultimate development hydrology as discussed in the
Existing Condition Detained Alternative.
>
Alternative A proposed maintenance includes grading within Agua Hedionda Creek to
remove accumulated sediment in the channel bottom. The Alternative A channel
maintenance will require re-grading Agua Hedionda Creek back to the original
trapezoidal channel geometry shown on the “Grading Plans for Rancho Carlsbad Mobile
Home Park” dated June 27, 1969 prepared by South Bay Engineering. The channel
consists of 2: 1 (horizontal:vertical) side slopes and a 44-foot to 58-foot bottom-width.
The channel will be graded down to the original channel elevation between the existing
drop structure and El Camino Real Bridge. At El Camino Real the ground elevation will
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begin to “ramp” up from the original channel flowline of 3 1.6 feet to the existing ground
elevation at cross-section 10.1 (elevation 35.5’). This alternative includes possible
complications related to the potential for continuous ponded water upstream of El
Camino Real. See Appendix E for the Alternative A HEC-RAS model.
Alternative B
Alternative B models the current channel topography within Calavera Creek, and models
the maintenance of approximately 3,100 feet of Agua Hedionda Creek between Cannon
Road Bridge and just downstream of Rancho Carlsbad Drive. ~s alternative models the
conveyance of the 1 00-year detained ultimate development hydrology as discussed in the
Existing Condition Detained Alternative.
Alternative B proposed maintenance includes grading within Agua Hedionda Creek to
remove accumulated sediment in the channel bottom while protecting the mature trees
that have established on the channel banks where possible. Upstream of the El Camino
Real Bridge this alternative will require grading a trapezoidal channel with 2:l side
slopes, with the top of the proposed graded slope starting near the toe of the existing
channel slope. The channel grading will project down to the original channel flowline
elevation and longitudinal slope of 0.3%, with approximately a 40-foot bottom width.
Downstream of the El Camino Real Bridge to Cannon Road, the channel will be re-
graded with a 70-foot bottom width and 2:l side slopes, to daylight. The channel
flowline will be graded at a 0% longitudinal slope fi-om the current elevation at the
northerly edge of the Cannon Road Bridge of approximately 32.0 feet, upstream until it
meets the original Agua Hedionda Creek flowline elevation shown on the 1969 plans,
approximately 135 feet upstream of the El Camino Real Bridge.
-7
This alternative minimizes impacts to the existing trees within the RCMHP. However,
grading activities downstream of El Camino Real are within an area of the Local Coastal
Plan (LCP) which is administered by the City and are subject to permitting requirements.
See Appendix G for the Alternative B HEC-RAS model.
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Alternative C
Alternative C models the current channel topography within Calavera Creek, and models
the maintenance of approximately 3,100 feet of Agua Hedionda Creek between Cannon
Road Bridge and just downstream of Rancho Carlsbad Drive. This alternative also
includes widening of a portion of Agua Hedionda Creek between El Camino Real and the
confluence with Calavera Creek to improve the channel capacity. This alternative
models the conveyance of the 100-year detained ultimate development hydrology as
discussed in the Existing Condition Detained Alternative.
Alternative C proposed maintenance includes grading within Agua Hedionda Creek to
remove accumulated sediment in the channel bottom while protecting the mature trees
that have established on the channel banks where possible. Upstream of the confluence
with Calavera Creek this alternative will require grading a trapezoidal channel with 2:l
side slopes, with the top of the proposed graded slope starting near the toe of the existing
channel slope. The channel grading will project down to the original channel flowline
elevation and longitudinal slope,of 0.3%, with approximately a 40-foot bottom width.
Downstream of the confluence with Calavera Creek to El Camino Real Bridge, Agua
Hedionda Creek will be widened by approximately 27-feet to increase the channel
capacity. A vertical wall is proposed along a portion of the right channel bank (looking
downstream). Downstream of the El Camino Real Bridge to Cannon Road, the channel
will be re-graded with a 70-foot bottom width and 2:l side slopes, to daylight. The
channel flowline will be graded at a 0% longitudinal slope fiom the current elevation at
the northerly edge of the Cannon Road Bridge of approximately 32.0 feet, upstream until
it meets the original Agua Hedionda Creek flowline elevation shown on the 1969 plans,
approximately 135 feet upstream of the El Camino Real Bridge.
Alternative C minimizes impacts to the existing trees within the RCMHP. Grading
activities downstream of El Camino Real are within an area of the Local Coastal Plan
(LCP) which is administered by the City and are subject to permitting requirements. The
construction of one vertical wall is required just downstream of the confluence of Agua
Hedionda Creek and Calavera Creek (between cross-sections 30 and 20). The wall will be
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up to 10 feet high and 275 feet long along the opposite creek bank fiom the mobile
homes.
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A second vertical wall may be required to protect an existing structure. This second
vertical wall located along the creek bank closest to the mobile homes will be up to 6 feet
tall and 120 feet long to preserve an existing structure.
In final design, it may be possible to implement an alternative solution to the wall(s),
such as adjusting the property line and/or the perimeter wall location, so that the slope
can be extended without the need for a retaining wall. See Appendix H for the Alternative
C HEC-RAS model.
Bridge Improvements
The hydraulic analyses of all alternatives except the No Action Alternative include
improvements to the bridges at El Camino Real and Cannon Road. These improvements include
connecting the piers under the bridge to create one elongated pier to minimize hydraulic losses .
and debris potential, as well as constructing a debris nose on the upstream face of the bridge .I
piers to minimize the impacts of floating debris on the hydraulics of the bridge crossing.
Preferred Alternative
Alternative C is the preferred alternative by the City of Carlsbad because it removes the largest
number of lots fiom the 100-year floodplain, while minimizing impacts to several of the mature
trees along the Agua Hedionda Creek channel banks within the RCMHP. Table 3 presents the
anticipated 1 00-year WSELs in Agua Hedionda Creek and the number of inundated lots for each
of the proposed alternatives.
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Table 3. Anticipated 100-year WSELs for the Agua Hedionda Creek
Grading Alternatives and Number of Inundated Lots
No Action Existing
Alternative Detained
49.6 48.6
50.2 49.2
I Detained 100-year WSEL (feet) I I I
Alternative A Alternative B Alternative C
48.5
48.8
48.8
48.8
48.6
49.0
49.1
43.1 42.8
43.9 42.0
43.9 42.8
44.9 44.8
46.0 46.0
46.6 46.6
47.2 47.1
70.58 50.4 49.4
120.2 50.5
170.19 50.4
. 210.51 51.3
49.5
49.5
50.9
The RCM" consists of mainly elevated foundations. Therefore, although a lot deemed as
inundated may not necessarily mean the home is entirely flooded. The finished floor elevation of
the structure may be above the floodplain, in which case an elevation certificate may be prepared
to ensure the structure is not within the floodplain.
250.41
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- Approximate
Inundated Lots
Maximum Water
Depth* Above 7.4 6.5 6.1 1.2 0.4
Channel Bank (feet)
Number of 278 210 141 45 12
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Additional Alternatives Investigated but not Analwed
The following alternatives were considered during the development
improvement alternatives. However, preliminary investigations determined
of the proposed
several alternatives
presented either limited flood control benefit or extensive engineering difficulties. Therefore, no
detailed analyses were prepared for these alternatives. The following provides a discussion of
alternatives investigated but not analyzed.
DSOD Jurisdictional Dam
Preliminary analyses of the feasibility for construction of a DSOD Jurisdictional Dam
upstream of the RCMHP was investigated to estimate the storage volume required to
provide flood protection within the RCMHP. The construction of additional detention
basins could minimize flooding in the RCMHP area without maintenance within Agua
Hedionda Creek.
The existing hydraulic capacity of the channel was determined using the HEC-US
hydraulic program by modeling .the existing topography in Agua Hedionda Creek with a
series of flows until the flow was contained within the channel through most of the
RCMHP. The HEC-US analyses show that the existing capacity of Agua Hedionda is
approximately 4000 cfs.
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In order to reduce 100-year flows in Agua Hedionda Creek to approximately 4000 cfs,
along with the construction of the Melrose, BJ, and BJB detention basins currently
proposed, the detention basin at Faraday would require an increased storage volume fiom
49.8 acre-feet (currently designed) to 200 acre-feet of storage volume, and an additional
detention basin would need to be constructed within the Agua Hedionda watershed that
what would provide 895 acre-feet of storage volume. The location of this additional
detention basin is located in the vicinity of the City of Carlsbad and the City of Vista
corporate boundary. This preliminary investigation has determined that constructing two
DSOD dams as additional detention facilities will result in a significant impact to
available open space, would impact not only the City of Carlsbad, but potentially the City
of Vista, and is therefore not a practical alternative.
Prepared by: Rick Engineering Company - Water Resources Division 25 DCB:KH:jfTReport/l3 182-D.002
12-13-04
h
Levees within RCMHP
The impact of constructing levees along the existing channel banks to increase the
capacity of Agua Hedionda Creek was investigated for the RCMHP project. Water
surface elevations for the Existing Detained analysis are 5 feet or more higher than the
top of the channel throughout the RCMHP. FEMA requires a minimum of 3 feet of
freeboard for levees over the 100-year water surface elevation, which would require
construction of a berm up to 8 feet higher than the current bank throughout the RCMHP.
This alternative would not be aesthetically acceptable for many homeowners within the
RCMHP, and to construct a berm of this size assuming 2:l side slopes would require
alrnost a 40’ wide footprint impact on each side of the channel. The construction of this
alternative would also impact approximately 53 property owners by requiring removal of
their homes. Also, if similar improvements were not made to Calavera Creek several
structures and lots would still be subject to inundation.
Box Culvert along El Camino Real
An alternative to construct a box‘culvert system to divert flows exceeding the capacity of
Agua Hedionda channel around the RCMHP and into Agua Hedionda Lagoon was
investigated. However, this structure would be required to convey approximately 3,500-
cfs and would require approximately 6 - l0’wide x 6’ high box culverts beneath El
Camino Real for approximately 2,500 linear feet. This option is cost prohibitive and has
significant constructability issues due in part to utility conflicts.
-~
Prepared by: Rick Engineering Company - Water Resources Division 26 DCB:KH:jf/Report/I 31 82-D.002
12-13-04
ONGOING MAINTENANCE PROGRAM
Once the initial channel maintenance and grading outlined by this project has been completed, it
is vital that ongoing maintenance including sediment removal and vegetation removal be
performed on a regular basis to preserve the capacity of the channel and to ensure an acceptable
level of flood protection within the RCMHP.
The maintenance area will begin at the north edge of the Cannon Road Bridge and extend
approximately 2,500 feet upstream to the drop structure underneath the Rancho Carlsbad Drive
bridge crossing. It is anticipated that ongoing vegetation removal maintenance will need to be
performed to ensure no vegetation becomes established between the aforementioned bridge
crossings.
It should be noted, however, that the sediment deposition in the channel is directly related to
each rainfall event and therefore, the frequency of maintenance may be more or less frequent
than anticipated. Monitoring of the sedimentation in the channel over the first few years
following the initial channel maintenance will be helpful in determining the future sediment '
removal maint ance fiequency requirements. Sediment posts marked in 1-foot increments can
be utilized in sections of the channel to assist in monitoring sediment depth. Once a depth of
approximately 2 to 3 feet of sediment has been accumulated, maintenance including sediment
removal between Cannon Road and the drop structure at the Rancho Carlsbad Drive bridge
crossing will be needed.
Bfs
The maintenance must be performed routinely by qualified personnel and a sufficient budget
should be established for the maintenance. If any questions arise during the maintenance, a
professional engineer specializing in water resources should be consulted. The maintenance of
Agua Hedionda Creek must be incorporated into the environmental permitting when processed
through the California Regional Water Quality Control Board - Region 9, the U.S. Army Corps
of Engineers, the California Department of Fish and Game, and the Coastal Commission if
appropriate.
Prepared by:
Rick Engineaing Company - Water Resources Division 27 DCB:KH:jfYReport/l3 182-D.002
12-13-04
I i
5 CONCLUSION i 1 Agua Hedionda Creek is highly subject to sedimentation for the majority of the creek. Portions
of the channel within the Rancho Carlsbad Mobile Home Park (RCMHP) have experienced up to
6 feet or more of sediment deposition since the original channel construction. This high
sediment load may be the result of agricultural areas upstream of the RCMHP as well as the
effects of an increased peak discharge within Agua Hedionda Creek due to development within
the upstream watershed. Because of the increased peak discharge and the accumulation of
sediment in the channel over time, the capacity of Agua Hedionda Creek to convey storm water
has diminished, and currently a significant portion of the lots within the RCMHP are subject to
inundation during a 100-year storm event. In an effort to minimize flooding within the Mobile
Home Park, the City of Carlsbad has investigated several alternatives to restore the capacity of
i
the channel and improve flood protection in the area.
Updated hydrygy for the watershed tributary to the RCMHP was prepared using HEC-1 to
determine the peak 100-year ultimate development runoff to the creeks. The detained hydrology
for the watershed models the construction of four proposed detention basins upstream of the . .i
Rancho Carlsbad Mobile Home Park; two within Agua Hedionda Creek, one at Melrose Drive
and one at Faraday; and two within Calavera Creek, BJ and BJB, near the intersection of the
Cannon Road and College Boulevard extensions. The results of the HEC-1 analyses were
modeled in the proposed alternative hydraulic analyses.
The implementation of the proposed maintenance alternatives for Agua Hedionda Creek includes
the following considerations: proximity of the project to the coastal zone, native and non-native
trees within the channel, environmental processing, and channel vegetation. Table 4 shows a
matrix summary of the proposed alternatives presented for the maintenance of Agua Hedionda
Creek. All of the following alternatives include the proposed ultimate detained hydrologic
conditions with the exception of the No Action*Alternative.
Prepared by:
Rick Engineering Company - Water Resources Division 28 DCB:KH:jffReport/l3 182-D.002
12-13-04
Table 4. Matrix Summary of Proposed Agua Hedionda Creek Maintenance Alternatives
I
Alternative 100-year Grading Discharge at Downstream
El Camino of El Camino
Real (cfs) Real
Effective 8,080 NO
No 9,195 No
FIRM
C 8,092 Yes
Bridge Pier Retaining Approximate Maximum 100-
Inundated Lots Above Channel
Number of year Water Depth
Yes 225
Yes No 163 I Yes No 33 ’ 1.2
Yes Yes 12 0.4
Each alternative was analyzed hydraulically to determine the number of lots removed from the
floodplain. The resulting water surface elevations were mapped, and the floodplain for each
alternative is shown on the map entitled, “Preliminary Rancho Carlsbad Channel and Basin
Project 100-year Floodplain Alternatives,” dated September 2004 included in Map Pocket 1.
Additional altepatives were investigated but not analyzed in detail, including: constructing a
DSOD Jurisdictional Dam, constructing lkvees within the RCMHP, or constructing a box culvert
along El Camino Real.
’I
*;
This report summarizes the maintenance design alternatives for Agua Hedionda Creek. In order
for the Rancho Carlsbad Channel and Basin Project to proceed into final design stages, the
following issues need to be resolved:
Initiate environmental permitting through the California Regional Water Quality Control
Board - Region 9, the U.S. Army Corps of Engineers, the California Department of Fish
and Game.
0 Initiate processing a Coastal Development Permit for maintenance of Agua Hedionda
Creek channel in-between Cannon Road and El Camino Real.
2
Prepared by: DCB:KH:jUReport/13182-D.002
Rick Engineering Company - Water Resources Division 29 12-13-04
__ . . . . . . -
1 Main Identity
From: "David Haaslet' < D haus@ci .carisbad .ca. us> To: cruthandbillarnold@sbcglobal. net> cc: <gvanpeski@adelphia. net>; "Glenn Pruim" <gprui@ci.carisbad.ca.us>
Sent: Monday, January 10,2005 4:38 PM Subject: Re: Sunday, January 9, 2005, rainfall
Mr. President,
through this last storm (at least so far). And congratulations on your
election to RCOA President. My next step m &is prejeCt is toset-upa
meeting with the City Engineer and Glen van Peski to map out our next
course of action. Glen is putting together a scope of services and
schedule for retaining a design and environmental fm. The issue that
requires a decision is whether we should obtain Council approval to
solicit proposals or to get the proposals and then proceed to Council.
As you are aware, the project scope changed with the latest proposal to
do work downstream of the bridge. Once that issue has been worked out,
we'll have something more useful to share with the RCOA board and can set a meeting to update you and the Board. I plan on swinging by this
afternoon to take a look at the Calavera Creek convergence at the weir.
David
Sorry for the delay in responding. Glad to hear you made it
David Hauser
Deputy City Engineer
Planning and Programs
dhaus.@ci .carlsbad.ca.us
(760) 602-2739
>>> <ruthandbillmold@sbcc@obal.neP 1/10/2005 12:26:35 PM >>>
The rainfall yesterday, particularly Sunday evening hit a high water
mark.
For the record the water level at the weir wall was over the top, or
more
that six feet. As we anticipated the oposite bank had erosion damage
right
up to the concrete curbing of our street. The installation of rip rock
and
concrete is certainly necessary. This will be part of our maintenance
site submission. The good news was that our streets did not flood and there
Was
only minor bank damage mostly on Calavera creek. We had set our own
water
height alarm system on the Agua Hedionda. It came within 3 inchs of
that.
Clearance of water under the El Camino Real bridge at 9pm last night
less than one foot. And the rain continues. We're only at the Was
W
1 /11/2005
** ~ 7
beginning of
meeting
time to discuss the revised flood mitigation plan and a timetable. Bill
a the traditional rainy season David, we await word fiom you for a
Arnold, President, RCOA
1/11/2005
GVP
Date:
Channel
Location:
Attendees:
Distribution:
Purpose
Consultants
ME€ TING MlNU TES
February 1,2005 Project: Agua Hedionda
Project No. 3338
City offices, 1635 Faraday Avenue, Rm 218, Carlsbad
Glenn Pruim, City Engineer
David Hauser, Deputy City Engineer
Glen Van Peski, GVP Consultants
Attendees
Jim Waltrip, Rancho Carlsbad Owner's Association Don Mitchell, McMillin Land Development
Roberta Cronquist, Rick Engineering Kathy Hacker, Rick Engineering
Dennis Bowling, Rick Engineering
Wayne Chang
Purpose of this meeting was to review the summary results of the December 12,2005 Rick Engineering report and discuss the next steps to the project.
Review of Report The report summarizes years of studies and numerous
alternatives. The removal of accumulated silt (and vegetation) from the channel between the Cannon Road and El Camino Real bridges, the widening of the channel near the confluence with
Calavera Creek, and the removal of silt in the Agua Hedionda
channel upstream of the El Camino Real bridge proved to be the key components necessary to restore flood protection to the Rancho Carlsbad residents. In addition, the planned detention basins BJ, Faraday and Melrose, BJB modifications, and the Lake Calavera outlet improvements are crucial to reducing the peak flows.
The report contains summary information in text and tables, and an exhibit that illustrates graphically the different alternatives examined, and the resuiting inundation limits for those alternatives. The CD with the report contains all the appendices and reference materials, as wdl as executable HEC-1 and HEC- RAS files. Copies of the HEC-RAS work maps are available upon request for consultants that need them.
Distribution The report was distributed to Rancho Carlsbad, O'Day Consultants, McMillin Land Development, Ladwig Design Group and Chang Consultants. A set of HEC-RAS work maps was
included in the report to Chang Consultants.
Scanning
Related Studies
Project Description
Schedule
A loose-leaf report binder was transmitted to David Hauser for scanning into the City Document Management System (DMS). However, Rick Engineering has provided a disk with all the report contents as well as the appendices. This is currently loaned out to Dokken Engineering, but upon return, Van Peski will review the file types to see if they can be directly input into DMS without
scanning originals.
Chang Consultants is currently studying the proposal to construct an 84" diameter pipe west on Cannon Road in lieu of routing stormwater along the north side of the Rancho Carlsbad perimeter wall. Additional studies may be necessary in conjunction with the processing of the RV Storage Facility by Rancho Carlsbad, to assess the impact of the proposed development proceeding ahead of all the elements of the Agua Hedionda Channel Maintenance Project being in place.
Van Peski presented a draft outline of the Project Description (attached). Hauser and Pruim made comments on items, which are reflected on the attached copy. The comments included adding the bridge support improvements, a discussion of related environmental work that has been done or is underway, and adding the possible clearing of the 8 x 8 RCB under El Camino Real, and some clarifying language. There was discussion of the proposed 84" bypass storm drain from Basin BJB, and the timing for that project.
Pruim recommended that as a failsafe, staff should get a proposal from the consultants doing the Master Drainage Plan update to include the 84" in the EIR being prepared for the update. Othetwise, the 84" would undergo environmental review with Robertson Ranch. Progress on Robertson Ranch huld be monitored, and if it looked like progress was slowing relative to the Agua Hedionda Channel Maintenance project, then the environmental would be done if the 84" construction was moved ahead of the development of Robertson Ranch.
There was discussion as to whether the limits of work for the project should be extended upstream of the planned limits of silt removal in Agua Hedionda Channel. Hauser suggested that, while no removals in this area may be necessary now, it could make sense to include them within the limits of the project, in case any future maintenance was required in those areas.
Per the last City memo regarding schedule, construction was estimated for Summer 2096. Whether or not this is achievable depends on a couple of key areas in the resource agency processing. Van Peski will sit down with Don Rideout and research City files on similar projects to refine our preliminary estimate of the schedule. Once an environmental consultant is on board, the schedule can be revised.
There was discussion of Ladwig's proposal to break out the portion of the project requiring a coastal permit from the rest of the project. Consensus was that it was better to keep the project together because the agencies preferred a complete project, and without clearing between the two bridges, the project didn't achieve flood protection goals. Excavation of the channel without
clearing between the two bridges would result in standing water, creating water quality, disease vector and safety issues.
Miscellaneous Addendum for REC Hauser indlcated he wanted to meet with Rick Engineering before approving an addendum for the extra work in preparing
the report.
Tile reports Van Peski reported he had just received the ordered title reports for the area between the two bridges. The issues of interest was the fee ownership, existence of Coastal Commission easements and/or other open space easements, and the existence of drainage easements. The hnro parcels are owned by the Carlsbad Canterbury Association and the Evans Point Homeowners Association, so neither is owned by a resource agency or other entity. Further research is necessary, but it appears that at least for the Evans Point parcel, the Coastal Commission deed restriction does not include the channel area.
It does not appear that drainage easements were granted in recent maps. There are older easements that will have to be researched to determine if they include drainage rights that pertain to the channel.
Rancho Carlsbad letter The January 17,2005 letter from Rancho Carlsbad did not request a written response, so none is planned at this time.
Weir structure repair Hauser reported that McMillin is proceeding with the environmental work necessary to repair erosion around the weir
structure.
Next Meeting
Action Items
- Item
The next meeting has not been set.
Person fs) Meet with Don Rideout, research schedule Research title information Prepare memo regarding 84" pipe Contact EDAW re task description for bio survey Research issue of RFP containing cost info Set up meeting with Rick Engineering re addendum Check file formats for report and exhibit files Get report into DMS Request cost for addendum to Master Drainage Plan for 84"
Due Date Resmsible
02/1 8/05 02/25/05 02/04/05 02/04/05 02/18/05 0211 0105 02/18/05
0311 1 I05
02/18/05
Van Peski Van Peski Hauser Van Peski Van Peski Van Peski Van Peski Hauser Hauser
Note: Pkaoe forward any additions, detetionr or corrections to these minutes within 5 working days to Glen Van Peski.
Project Description DRAFT OUTLtNE
Agua Hedionda Channel Maintenance Project No. 3338-1
Backaround
Proiect Objectives Restore 100-yr. flood protection to residents of the Rancho Carlsbad Mobilhome Park.
Proiect Elements Remove accumulated silt from Agua Hedionda Channel, from El Camino Real
upstream Widen confluence of Agua Hedionda Channel and Calavera Creek Remove accumulated vegetation and silt from Agua Hedionda Channel between downstream face of Cannon Road Bridge and upstream face of El Camino Real
bridge Modify weir structure at outlet from Basin BJB
Modify inlet structure to Basis BJB outlet Modify bridge piers at Cannon Road and El Camino Real Bridges Construct "noses" on bridge piers at Cannon Road and El Camino Real Bridges Clearing of 8' x 8' box culvert under El Camino Real Environmental Mitigation
Related Proiects 10 Lake Calavera outlet reconstruction
11 Construct 84" RCP along Cannon Road
12 Construct Basin BJ 13 Construct Faraday Basin
14 Modify Melrose Basin
Onaoina Maintenance Activities
1
2 Monitoring of Mitigation/Restoration Area
Removal of silt and vegetation in Agua Hedionda Channel
Proiected Schedule
1 Initial construction activities
2 Ongoing maintenance activities
Related Environmental Review 3 CoIlegelCannon (Basin BJB)
4 College (Basin BJ) CantarinVHolly Springs
5 Lake Calavera outlet structure repair 6 Master Drainage Plan update
7 Robertson Ranch Master Plan
I
r I t
I
1
!
i
I
I
I i i
February 7, 2005
AllReccivr, For the Information of the:
CITYCOUNC~
To : City Manager
From: Deputy City Engineer, Planning and Programs
RANCHO CARLSBAD FLOOD CONTROL PROJECTS
Glenn asked that I provide you with a brief update on the status of the RCMHP flood
control projects together with a response to the Owner Association’s request to
advance construction of the proposed 84-inch storm drain in Cannon Road.
The attached matrix lists the various flood control projects and presents a brief
description of their location, description, estimated cost and current design and/or
construction status.
With regards to the request to advance construction of the proposed 84-inch storm
drain staff has and will continue to investigate various possible scenarios. At this
time, McMillin Homes is proceeding with their Robertson Ranch project, which
includes the 84-inch storm drain alternative. The Ranch project is well along on its
environmental review process and McMillin’s engineers have already prepared the
initial hydraulic studies for the 84-inch storm drain alternative. Realistically, McMillin
would not be in a position t
project until the fall/winter f 2006.
The schedule could be advanced at ieast 6 to 8 months by making the 84-inch storm
drain a standalone City project. Since funds are currently appropriated for the
Calavera Creek and Basin BJ improvement project, we could immediately initiate
preliminary engineering and environmental review. This process would take a
minimum of six months to complete. Since the project is located almost wholly
within existing ROW (with perhaps some minor ROW needed at the outfall), and
since there should be little objection from the resource agencies, the project could
proceed to design and be ready for bidding by the end of this year.
nstruction on the Ranch and storm drain CT3
It should be noted that the City’s budgeted PLDA funds for the combined Basin BJ
and Calavera Creek improvement are not adequate to fund all the improvements
required of these projects including Basin BJ, relocation of the RCMHP RV storage
lot and community garden and construction of the 84-inch storm drain. As better
cost estimates become available and as we proceed with the analysis of the PLDA
fee program as part of the Master Drainage Plan (MDP) update, we will better know
the extent of the shortfall and also know if the shortfall can be made up through an
increase in or restructuring of the PLDA fee program. The answers to these
questions will not be known until we are further along with the update to the MDP
perhaps by tmsummer. -
As an alternative to making this a public project, we can work with McMillin Homes
to ensure that the storm drain project can move forward separate from the Ranch
development. This can be accomplished by incorporating a phased construction
,scenario within the Robertson Ranch EIR thd will allow the storm drain project to be
constructed ahead of the Ranch development. In the event the Robertson Ranch EIR
is itself held up, we can include the 84-inch storm drain project within the upcoming
Master Drainage Plan EIR or process a separate environmental document.
I believe McMillin would be receptive to having the storm drain plans prepared as
stand alone facility. By use of a reimbursement agreement, we could entice them to
enter into an arrangement whereby we could take over the design contract in the
event their development project is delayed. In such event, the City Council could
decide to advance funding to the project and have staff proceed with bidding and
constructing the project. Assuming McMiffin ccntinues with their devewns,
?hey would then proceed to construction as a private project under reimbmt
agreement with the City. There may be other options to work Zth Mcmn- to
ameir storm drain construction schedule. Further discussions would be
needed internally and with McMillin Homes to more fully explore these alternatives.
_c_ -.-
~
David Hauser
Deputy City Engineer
Planning and Programs
C Deputy Public Works Director, Engineering Services
Basin BJB Nonhrast comer 01
Cahmn Road and Cdlege
0oulavard
Road
Faraday Lain South side of Faraday
Amua wrst 01 El Fuene SQOOt
East side 01 Melrosa
Drive south of Faraday Awnue
Agua Hedwda From downstraam lace
Channel Oredging 01 Cannon Road bridge to
and Improvamant appoximately 2400 teet
mast of El Camno Real.
Melnue Baain
Calavera Crwk
ImprovamantIBypa the amsting Calavera
Nonh of and parallel to
SI
Calavera Creek
Erosion
mainlenance
Crank Channel lrom
Collage BouIwird to El
Camino Raal
At creak conlluence with
outlal to Basin BJB
RANCHO CARLSBAD FLOOD CONTROL PROJECTS PROJECT STATUS SHEET
Fabrualy 2,2006
Description I Estimated Cost
Retantion basin $2.700.000 . 16 Aeras I . 49 Acre-feet
Retention basin I $2.500.000 . 8 acres Amount budgeted for canbind Basin BJ and . 49 acre fwt Calavara Creek Channel Improvements. TXs - includes relocation 01 RCMHP RV Moraga lot. community
garden and maintemnce Iacility
amount repasants the maximum amwnt 01 RDA
funds aveilaMa under currant PLOA la0 program.
Additional hmdhg will likely be requirad to
complata project due to large cost of relocation of RCMHP faci0ti.s.
Retention ham $300.MK) .49 zcrn Iwt
I Retention basin Not known. . 49 acre feet Fwdad by developer
Channel improvamsnt $1,260,500 . dredging Current amount budgated lor proi.ct. Addltional . widening et conlluence with fUnding may be raquied dum to high cost
Calavara Creak environmental mitigation.
Drainage channel may b. -
- an 84' pipe within the Cannon raquimd.
Slope MmOnng and miscellaruous Unknown
bank rapair resulting from turbulence
created by new weir outlaU
Included in Barin W con wtimata above.
Budgeted lunds lor thii laciliiy are combined with
Basin BJ funding. Additional lunds wlll likily b.
open channel n& of the
existing RCMHP wall: or.
Road ROW
Status Comprelcd wmr of 2004
Schde is dev4op.r dopandent. Wble stm of connruction by and of 2005.
Envimnrmntal canilicatlon and nrouca agancy pennits have baen obtained. Awaiting design and
ConStNction as part 01 Canterini and Holly springs
project. RV reloution site Planning applications have
hn rubmittad and ara under rWnw by ciw.
~IWUUCtbn begun hwery 2005.
Construction begun JMUW 2005
EulisH mnrVuction Man date wodd b. fmU of 2006
assuming agency wrrnita can ba obtains& Revisad hydrology lor alternatives ansly*% comp(eted.
Currently, preparinp scopa of work lor salemion of an
enginasring dmign lirm and anvironnuntal consultant
to prapare EIR and preliminary design plens.
Earliest construction ntan date wodd k sprinpllummer Of 2006 dmpmndent on lunding and
ennmmnantal approval.
Hydroboy Mudiea Complet~. Altarmthn .nal*s unda
reviaw as pan of tha RobenMn Ranch Em.
Not 8chduled.
Currently making damgs mSHesment% md working
with McMillln Homos to determine hat means to
effect repairs
February 11 , 2005
Bill Arnold, President
Rancho Carlsbad Home Owners Association
5500 El Camino Real
Carlsbad, CA 92008
DRAINAGE IMPROVEMENTS
Dear Mr.
Thank you for meeting with Council Member Ann Kulchin, City Engineer Glenn Pruim
and I on Wednesday, February 9, to discuss your concerns regarding drainage
improvements related to the Rancho Carlsbad Home Owners Association (RCHOA).
Council and staff certainly understand and share your concerns regarding the potential for
flooding in the park and are devoting considerable resources to solving the drainage
issues. The photos and descriptions provided at our meeting helped highlight the areas of
concern.
As we discussed at the meeting, there are numerous flood control improvement projects
required to comprehensively address flooding within the RCHOA. The improvements
consist of four flood control detention basins, a drainage channel dredging and clearing
project and a storm drain. One of the basins, BJB, was constructed by McMillin Homes
in conjunction With the extension of College Boulevard as part of the Calavera Hills
Phase IT project. This basin is currently operational and providing valuable flood control
benefits. Another basin, BJ, will be constructed as part of the extension of College
Boulevard, between Cannon Road and El Camino Real. This basin will be constructed
by the developers of the Cantarini and Holly Springs projects, which recently received
certification of their Environmental Impact Reports.
The timing of these improvements will depend on the private development schedule, but
could begin within the next two years. The other two basins are components of the
extensions of Faraday Avenue and Melrose Drive, both of which are under construction
and should be completed within 18-24 months. The clearing and dredging of Agua
Hedionda Channel through the RCHOA has been the subject of many studies and
conversations. The City is the lead on this project and has recently completed the study
that will be the basis of the focused discussions between the City and the Resource
Agencies as part of the permitting process. It is always difficult to predict when
environmental permits will be obtained from the Agencies but the City will aggressively
pursue the required permits. The last improvement project, and the focus of our meeting
last Wednesday, is the 84" storm drain proposed to be constructed within the Cannon
Road rights-of-way.
1200 Carlsbad Village Drive - Carlsbad, CA 92008-1989 (760) 434-2830 - FAX (760) 720-9461 @
Bill Arnold
February 11,2005
Page 2
As you are aware, the recent construction of Basin BJB included a basin outlet pipe that
runs diagonally under College Boulevard and Cannon Road before discharging just north
of the RCHOA northerly wall. In addition, a flow-splitting structure was constructed to
ensure that the low flows continue to join the existing Calavera Creek to satisfy
environmental requirements. The higher volume flows continue along the drainage
course that lies just to the north of the RCHOA wall. Future development along the north
side of this wall, including the Robertson Ranch East Planning Area 22 and the relocation
of the RCHOA RV Storage Area and Community Garden, will require drainage
improvements to accommodate these higher flows. The current proposal is to construct
an 84" storm drain line that will connect to the Basin BJB outlet pipe and extend westerly
within the future widening area of C&on Road before discharging on the north side of
Cannon Road, east of El Camino Red. The main focus of our discussion with you last
Wednesday was how to accelerate the construction of this storm drain.
At our meeting, we explained that the City's current position is that the storm drain
would be constructed as part of the Robertson Ranch East development, under a
reimbursement agreement with the City. This is consistent with how the City in the past
has dealt with major infrastructure within future development areas. As expressed by
yourself and Russ Kohl, the RCHOA is concerned that the Robertson Ranch development
could get delayed due to environmental issues, which would delay the construction of this
important flood control improvement. RCHOA requested that the City take the lead on
the project to expedite the construction of the improvements and avoid any delays
associated with the private land development project.
The day following our meeting, Thursday, February 10, I met with Brian Milich, of
McMillin Homes, to discuss the construction of the 84" storm drain. Council Member
Ann Kulchin and Glenn Pruim also attended that meeting. After considerable discussion,
we have arrived at what we feel is this best way to proceed with this project. We still feel
that the storm drain should be constructed by McMillin. They have completed a
preliminary design of the facility and they have included the project in their
environmental documents to date. Additionally, it would be beneficial to construct both
the storm drain and Cannon Road improvements at the same time. The City has not yet
started either the design or the environmental work for this storm drain and is therefore
behind the developer's schedule. Regardless of who constructs the storm drain, it is
unlikely that the improvements would be completed before the next rainy season.
Allowing for design, environmental clearance, permitting, advertising, awarding a
contract and constructing the improvements will take well over one year. Our goal at this
time is to have the storm drain improvements completed by the end of the third quarter of
2006, which would be in time for the 2006/2007 rainy season,
.
Bill Arnold
February 11,2005
Page 2
The developer has assured the City that they can meet this schedule. Their current
schedule indicates that they plan to go to City Council for approval of their Master Plan,
Master Tentative Map and Environmental Impact Report in the September/October
timewe of this year. Subsequent to obtaining those approvals, they would make the
construction of the 84” storm drain and Cannon Road widening their first priority. Based
on this schedule, and with appropriate project conditions, the storm drain improvements
should be in place by September of 2006. Additionally, to address the concerns about
potential delays to the Robertson Ranch project affecting the timely construction of the
storm drain, McMillin has agreed to process the design and environmental clearance of
the storm drain as a separate project, concurrently with the processing of their private
development. In this way, if there were actual or anticipated delays to their project, the
City could take the plans and environmental approvals and move forward with the
construction of the storm drain as a City-sponsored Capital Improvement Program (CIP)
project. This could require a change to the approved CIP by the City Council but would
not pose a significant delay.
The City understands your concerns and is fully committed to ensuring that RCHOA is
provided with every level of flood protection possible. We are confident that the
arrangement we have discussed with McMillin Homes will result in the most timely
construction in a manner consistent with the City’s current policies and practices. I
appreciate the time and patience that you and the RCHOA have afforded us. We look
forward to working with you to solve the existing drainage issues as soon as possible.
If you have any questions, or require additional information, please do not hesitate to
contact myself at (760) 434-2830 or Glenn Pruim at (760) 602-2407.
n Sincere1 v
$OD” LEWIS
Mayor
c: City Council
City Manager
City Engineer
Deputy City Engineer, Planning and Programs
Brian Milich
a\ R! &%&&?? Owners' Association, Inc.
5200 El Carnino Real, Carlsbad, California 92008
Phone: (760) 438-0333 Fax: (760) 438-1 808
February 22,2005
Mi-. Glenn him, Chief City Engineer
City of Carlsbad
1635 Faraday Avenue
Carlsbad, CA 92008
Re: Dredging of the Agua Hedionda
Dear Glenn:
As you know, the dredging of hs stream is the central issue of the flood control problem for
Rancho Carlsbad. The last word I received was an E-Mail from David Hauser dated January 10
indicating that you hadn't formulated a plan, hired an environmental consultant, etc. to get this
moving. Where are we in this process?
As I said to you at our breakfast meeting on February 9", five governmental agencies must sign
off on any plan, but until they have something to review, we are at a standstill.
very truly yours,
Bill Arnold, President
CC: Carlsbad City Council
/
"f
3.2 zd &&&d Owners' Association, Inc.
5200 El Carnino Real, Carlsbad, California 92008
Phone: (760) 438-0333 Fax: (760) 438-1 808
February 22,2005
Mayor Bud Lewis
City of Carlsbad
1200 Carlsbad Village Drive
Carlsbad, CA 92008
Dear Mayor Lewis and Council Members:
Thank you for your efforts to accelerate permits needed to provide additional flood protection for
Rancho Carlsbad homeowners, specifically the proposed 84" in Cannon Road between El
Camino Real and College Boulevard.
In going through your letter of February 1 1 , there are a number of concerns I would like to
address to you as follows:
1. Our main concern is that you have stated that the timing of these improvements
will depend on private development schedule.
Discussion: This has been a major concern of ours all along, especially in this area of
the City of Carlsbad. Projects are being challenged and resolution of issues cannot be
determined at this stage of the development of the Robertson Ranch.
2. Your statement that the storm drain would be constructed as part of the
Robertson Ranch east development under a reimbursement agreement with the
City.
Discussion: Here again, the schedule is dependent upon the Robertson Ranch
approvals and again the schedule cannot be determined at this time.
3. This is consistent with how the City in the past has dealt with major
infrastructure within future development areas.
Discussion: Even though this may be the policy in the past, we are concerned and have
every right to believe that tlus is a special circumstance. We cannot think of another
instance in Carlsbad where the timing of public improvements is so important for a
safety and welfare issue. The City's concern has always been that what's good for one
should be good for all. Our response to that is that each project should stand on its
own merits. I don't think accelerating the construction of an 84" pipeline is going to
be precedent setting for any other project within the City.
4. Your statement that it would be beneficial to construct both the storm drain and
Cannon Road improvements at the same time.
Discussion: It's a major concern of ours to add Cannon Road improvements to the
storm drain project. The major concern that we have is that from an environmental
review standpoint, the road has to address a lot of issues that a storm drain would not.
Specifically, traffic generation, air quality impacts, cumulative impacts, public safety.
To add the road to the environmental review for the storm drain, in our mind, is a
significant set-back to trylng to achieve the construction of the 84" pipeline. In
addition, until an environmental process has been certified by the City for the storm
drain, Rancho Carlsbad is prohibited from moving forward with their relocation
project. The Planning Commission could not make a decision on our project,
assuming that some future environmental document ,and action is going to be
approved, Le., the construction and environmental effects of the 84" pipeline. Taking
this approach puts our efforts totally on hold. Your City staff would not know how to
review our project that has been submitted. Will we be in the flood plain or will we
not be in the flood plain? Will there be significant water going underneath our access
road, or will there be no water going under access road? In addition, a large portion of
OUT project is currently in the flood plain. After the construction of the 84" and the
adjustments to the FEMA maps, our area will no longer be in the flood plain. The
approved HMP document does not allow filling in the flood plain. Again these are
major concerns of ours and if the City's proposal is the way the pipeline will be
processed, we will have a lot of residents very upset by this action.
5. The statement that the developer has assured the city they can meet this schedule
(third quarter pf 2006, which would be in time for 2006-2007 rainy season).
Discussion: We don't believe anyone can guarantee or assure the City that they can
meet any schedule in this day when projects consistently are challenged.
6. Subsequent to obtaining those approvals, they would make construction of the
84" storm drain and Cannon Road widening their first priority.
Discussion: Here again, the 84" is not your first priority today, it only according to
your letter, becomes a first priority once all the other approvals are obtained which
include the widening of Cannon Road.
7. McMillin has agreed to process the design and environmental clearance of the
storm drain as a separate project concurrently with the processing of their
private development.
Discussion: We agree with McMllin to process the design and environmental
clearance of the storm drain as a separate project. The 84" must remain separate from
the private development and road project.
8. The City could take the plans and environmental approval to move forward with
the construction of the storm drain as a City sponsored CIP project.
Discussion: It is our understanding that McMillin has authorized their engineer to
proceed with the design of the 84". We appreciate McMillin doing that and would
encourage that to continue, but Without the widening of Cannon Road. In addition,
it is important to have McMillin process, as quickly as they can, the environmental
work for just the 84" so that again it will be a separate project, separate from the
widening of Cannon Road and all the cumulative and environmental effects connected
to the road.
One more reason for prompt installation of this 84" pipe would be to help correct a problem
caused by the installation of the concrete box culvert and weir wall. This concentrated water
flow in heavy storms is damaging our stream bank and undermining our street opposite the weir.
A properly designed diversionary pipe would reduce the velocity and volume of the water.
Again, we thank you for your letter of February 1 1, but we would request another meeting with
you and yow staff and other Council members to discuss our concerns addressed in ths letter.
Sincerely,
Bill Arnold, President
CC: Mark Packard, Mayor Pro Tern
Matt Hall 3
Ann J. Kulchin
Norine Sigafoose
David Hauser, Deputy City Engineer
Glenn Pruim, Chief City Engineer
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,d&& M /DAY DAY OF WI.
Q-y&
Hours (From - To)
E! &e Owners’ Association, Inc.
5200 El Camino Real, Carlsbad, California 92008
Phone: (760) 438-0333 Fax: (760) 438-1 808
March 1,2005
Mr. Raymond R. Patchett, City Manager
City Of Carlsbad
1200 Carlsbad Village Drive
Carlsbad, CA 92008
Dear Mr. Patchett:
On behalf of our Owners’ Association, I am requesting that we be placed on the agenda at the
next scheduled meeting of City Council, March 15,2005.
The purpose for this request is to allow our Association to address the full Council in open forum
of our frustration in getting city government to give priority attention and timely implementation
of the city’s flood control program for Rancho Carlsbad. We are fully cognizant of the many
outside governmental agencies hurdles that this plan must overcome. What I am speaking about,
are those sections of the plan that are within the control of the City and the inordinate time it
takes to get thmgs accomplished.
City Council needs to be made aware of our concerns, set priorities and remove us as promptly as
possible from the devastating effects of a major flood. This years excessive rainfall has re-
awaken us to this flooding potential. Fortunately, mother nature has been kind to us, so far, but
in several of these storms an hour’s more of heavy rain would have caused the creeks flowing
through our community to breach and threaten the property and lives of our residents.
In the City Council’s values statement you make reference to providing a “safe community”,
“top quality service”, and “timely response”. The City has an obligation to protect the citizens
of its community and in our view, it is failing to meet that obligation.
Thank you.
Bill Arnold
President
RANCHO CARLSBAD HOME SALES
5200 El Camino Real Carlsbad, CA 920.08
“We’re always on site to help you!”
Tel: 800-808-8895 Fax: 760-438-4895
03/02/05
Bill Arnold
RCQA
RE:, HUD Reverse Mortgage Flood Plain requirements.
‘ Dear Mi. Arnold,
The attached letter from HUD states we need to obtain a FEMA issued LOMA or LOMR
flood plain revision report for this community. We apply for these &om FEMA after we
have engineers state that all lots in Rancho Carlsbad have been removed from the Flood
Plain.
According to the City of Carlsbad there are 139 lots in the flood plain.
Best regards,
Clyde Billings
('; I
U.S. DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT
Santa Ana Homeownership Center
1600 North Broadway
ww. hud .gov
Smta An& CA 92706-3927
Clyde Billings
Rancho Carlsbad Home Sales
5200 El Camino Real
Carlsbad, CA 92008
JUN 25 2004
Dear Mr. Billings:
Subject: Rancho Carlsbad Country Club Estates - Manufactured Home Condominium Community
Thank you for your letter of June 21,2004. The Santa Ana Homeownership Center (SAHOC)
has completed review of the documentation and correspondence provided. The SAHOC has determined
that there are several obstacles with regard to Federal Regulations and FHA insurance eligibility
requirements that affect the properties located within Rancho Carlsbad Country Club Estates. The
SAHOC does not have the authority to waive them at this time.
The SAHOC is not empowered to change the regulations, but is simply tasked with enforcing
laws and provisions made by Congress for FHA Programs and FHA insurance. General overall risk has
been evaluated and these regulations have been established to protect the viability of the FHA Insurance
Fund and provide for the continuance of FHA programs.
Correspondence to you dated February 27,2004 and our subsequent telephone conversation of
March 3 1,2004 both addressed the necessity of obtaining a FEMA issued LOMALOMR for the project
prior to many possible consideration of pursuing a waiver for project approval. Regrettably this is still
the case. Your facsimile of June 21,2004 documented the progress that has been made in your pursuit
of the LOMR. Once this has been accomplished, the SAHOC will be more than willing to revisit a
subsequent request.
I hope that this letter has clearly defined our current position and abilities with regard to your
request.
Sincerely yours,
Danny Mendez
Director
Processing and Underwriting Division
Page 1 of 1
From: "Bob Ladwig" <Idg@dwilsoneng.com> To: ~nrthandbillamold@sbcglobal.ne+ cc: '"David M. Bentley"' dmbentley@comcast.ne+; "'Russ Kohl"' <RMKOHL@aol.com>; "'Jack
Jam" cjacjaf@sbcglobal.net>; '"Jim Waltrip "' cjimnoreenw@earthlink.net>;
<murphy@adelphia.net>; "'Sue Loftin"' cslof&in@loftinfirm. corn>
Thursday, March 17,2005 10:24 AM Sent: Subject: Rancho Carlsbad Drainage
Bill,
After thinking of all the discussions we've had about drainage, I reviewed the June '98 and May '02 and December '04 Rick Engineering reports. I also looked at the FEMNFIRM maps that are dated June of
'97. All reports assume your north wall is a flood wall or will be a flood wall. Some areas near our
proposed bridge crossing there is close to a 4' difference in 100 year flood plain elevation from one side
of the wall to the other. All the house counts and water surface elevations within the park assume a flood wall is in place. No studies exist based on existing (no flood wall) conditions. In other words, there has been to date, a gross underestimation of the 100 year condition. Even the Weir wall has been constructed to divert flows to the north side of the wall. To say it in other terms, the Owners have never been told the real condition they are living in. I talked to Glenn Van Peske this a.m. and he confirmed
that there is no existing condition analysis.
When you make your presentation to the Council on April 5th, you should point these things out as the primary reason why this is a City problem to solve now and not tie it to a developer's schedule.
Bob
3/22/2005