HomeMy WebLinkAboutCT 14-09; UPTOWN BRESSI RANCH; GEOMORPHIC ASSESSMENT; 2014-11-24RECORD COPY
6/-4GOMORpHIC ASSESSMENT
Int Date t I FOR
BRESSI RANCH
(LOTS 29 THRU 32)
(PRELIMINARY ENGINEERING)
Job Number 17169
November 24, 2014
GPA 12-02/MP 178(H)/CT 12-02/PUD 12-05
ENGINEERING COMPANY
rickengineering.com
GEOMORPHIC ASSESSMENT
FOR
BRESSI RANCH
(LOTS 29 THRU 32)
(PRELIMINARY ENGINEERING)
Job Number 17169
GPA 12-02/MP 178(H)/CT 12-02/PUD 12-05
Jayne M. Janda-Timba, P.E.
R.C.E. #70649
Exp. 06/15
Prepared for:
Sarah Morrell (Owner)
Shea Homes
9900 Mesa Rim Road
San Diego, California 92121
Kevin McCook (Owner)
Shea Business Properties
9900 Mesa Rim Road
San Diego, California 92121
Prepared by:
Rick Engineering Company
Water Resources Division
5620 Friars Road
San Diego, California 92110-2596
(619) 291-0707
November 24, 2014
TABLE OF CONTENTS
1.0 Introduction . 1
2.0 Point of Compliance (POC) . 1
3.0 Domain of Analysis (DOA)............................................................................................................2
4.0 Initial Desktop Analysis..................................................................................................................3
5.0 Field Screening: Vertical and Lateral Susceptibility ......................................................................3
6.0 San Diego BMP Sizing Calculator Results.....................................................................................5
FIGURES
Figure1: Vicinity Map ........................................................................................................................... 1
APPENDICES
Appendix A: Geomorphic Assessment Results
Appendix B: Geomorphic Assessment Exhibits
Appendix C: Field Photographs
Prepared Ey: JJT:JMC:vs/Reportll7 169.001
Rick Engineering Company - Water Resources Division 11-24-14
1.0 INTRODUCTION
This report summarizes the geomorphic assessment results for Lots 29, 30, 31 and 32 of the
Bressi Ranch community in the City of Carlsbad (herein referred to as "the project"). The
project encompasses a 17.7 acre site and is located at the southwest corner of the intersection of
Palomar Airport Road and El Fuerte Street; the intersection is located approximately 0.5 miles
east of the intersection of Palomar Airport Road and El Camino Real. Gateway Road fronts the
property along the south and Colt Place fronts the property along the west.
INNOVATION WY
iOaAviw
IRPORT RU (A Tr4'Ay RD
PAiOMAR A
MAR
SITE
call FL '.
VICINITY MAP
The analysis presented herein is in support of the entitlement phase of the project which includes
processing a General Plan Amendment, Master Plan Amendment, and Site Development Permit
to change the land use and zoning from Commercial/Industrial to Multi-Family Residential and
Commercial/Industrial.
2.0 POINT OF COMPLIANCE (POC)
The initial step in performing the SCCWRP channel screening analysis is to identify the point of
compliance (POC). Storm water runoff from the subject property is collected on-site and
conveyed within an existing public storm drain system located within Gateway Road; the
backbone system conveys runoff westerly within Gateway Road then southerly within Alicante
Road ultimately discharging to a regional detention basin. Subsequently, the existing detention
Prepared By: JJT:JMC:vsIReportll7l69.001
Rick Engineering Company - Water Resources Division 11-24-14
am
I
I
I
1
I
I
I
I
I
1
I
1
I
I
I
I
I
I
1
basin outfalls to an open space area, this is the geomorphic assessment point of compliance
(POC). Refer to the Geomorphic Assessment exhibit located within Appendix B.
3.0 DOMAIN OF ANALYSIS (DOA)
The next step is to defire the domain of analysis (i.e., upstream and downstream sudy limits).
The Final HMP, dated March 2011, specifies that the downstream domain of aialvsis shall be
based on the following criteria (whichever is reached first governs):
. At least one reach downstream of the first grade-control point
tidal backwater/lentic waterbody
equal order tributary
A 2-fold increase in drainage area
Based on the evaluation of each bullet item above, the downstream limit for the DOA is a lentic
waterbody located approximately 820 feet downstream of the POC. The lentic water body is
designated as a Habitat Con;ervation Area;
--
Said area is identified with:n the City of - - j7...........
_P tilsbad's Master Plan of Drainage Facilities
is a "lake, reservoir, or pond.' Refer to Plate
C-3 located within Appendix B. The lentic
--
water body is located upstream of the nearest
-trade control point and/or equal order
iv
-• tributary. The drainage area to the POC is
' approximately 142 acres, the total
/........ -.: accumulated area at the lentic waterbody is 1
- •. - h approximately 193 acres.
Prepared By: JJT:JMC:vs/eport/i7ie9 001
Rick Engineering Company - Water iesources Division 11-24-14
2
The upstream limit of the DOA is extended 20 channel widths Upstream of the POC. The
upstream limit is located approximately 300 feet upstream of the POC.
Based on the above information, the study reach has been divided pursuant to the SCCWRP
criteria described in the Final HMP, dated March 2011, The result is a total of three (3) reaches,
two (2) reaches downstream at 420 feet per reach and one (1) reach upstream at 300 .feet.
Photographs from the field visit are included in Appendix C.
4.0 INITIAL DESKTOP ANALYSIS
Once the domain of analysis is defined, the Final HMP requires an initial desktop analysis to be
completed. The required input data in the initial desktop analysis are contributing area in square
miles, mean annual precipitation in inches, valley slope, and valley width in meters. This
information was obtained using City of Carlsbad topographic information (5-ft index contours),
aerial. photogrammetry dated March 2009, area-weighted annual precipitation via USGS, and the
City of Carlsbad's Master Plan of Drainage Facilities. The initial desktop analysis for each reach
is included in Appendix A.
5.0 FIELD SCREENING: VERTICAL AND LATERAL SUSCEPTIBILITY
After the initial desktop analysis is completed, a field visit is required to assess the vertical and
lateral susceptibility of each channel reach for each DOA. As part of the field visit,
measurements are conducted including observations or pebble counts to determine d50,
measurements of the bank height and bank angle, and assessing bottom widths of the channel.
These field observations and measurements are used throughout the channel screening tool to
identify a vertical susceptibility rating and lateral susceptibility rating. These ratings then
correlate to a low, medium, or high susceptibility for vertical and lateral susceptibility, which
then results in a combined channel susceptibility for each reach.
Prepared By: JJT:JMC:vs/Reportll 7169.001
Rick Engineering Company - Water Resources Division 11-24-14
3
In order to assess vertical susceptibility rating, a SCCWRP vertical susceptibility flow chart in
the Final HMIP, dated March 2011, was used as a guide to determine each reach's susceptibility.
In regards to the channel bed resistance, "Intermediate Bed" was selected for each reach since
the existing channels are densely vegetated, which is most representative of the "hardpan of
uncertain depth" criteria. Since the Intermediate Bed was selected, additional steps were
required to determine the vertical rating and susceptibility. In order to determine the vertical
rating, three (3) risk factors needed to be evaluated: armoring potential, grade control, and
proximity to incision threshold. A letter grade (A = 3, B = 6, and C = 9) was assigned to each
risk factor based on the field observations and SCCWRP guidelines. As a result, each reach
received the following grades for each risk factor: B for armoring potential, B for grade control
and B for proximity to incision threshold. Therefore, with the SCCWRP vertical susceptibility
rating equation, each reach in Basins 200 and 300 receive a rating of 6.0. Since this rating is
greater than 4.5 but less than 7, the vertical susceptibility is "medium," as defined by SCCWRP.
Please refer to the supporting vertical susceptibility forms in Appendix A for more details.
In a similar manner, a SCCWRP lateral susceptibility flow chart in the Final HMP, dated March
2011, was utilized to assess the lateral susceptibility for each reach. It was determined that each
reach exhibited the following characteristics: (1) densely vegetated with both banks consolidated,
(2) bank instability factor of less than 10 percent, vertical rating less than high, and (4) a valley
width index (VWI) greater than 2. Therefore, according to the SCCWRP Form 5, titled
Sequence of Lateral Susceptibility Questions Option, the channels received a "medium" rating
for lateral susceptibility. Please refer to the supporting lateral susceptibility Appendix A for
more details.
In summary, the vertical and lateral susceptibility for the channel reaches downstream are
"medium."
Prepared By: JJT:JMC:vs/Reportll7 169.001
Rick Engineering Company - Water Resources Division 11-24-14
4
am
6.0 SAN DIEGO BMP SIZING CALCULATOR RESULTS
The final step of the geomorphic assessment is to determine the channel susceptibility and low
flow threshold using the San Diego BMP Sizing Calculator (i.e., "POC" tab). The required input
data in the San Diego BMP Sizing Calculator are watershed area, vertical susceptibility, lateral
susceptibility, channel bed material, channel top width, channel bottom width, channel height,
and channel slope. The San Diego BMP Sizing Calculator output, including the supporting
SCCWRP channel screening results, is included Appendix A. The San Diego BMP Sizing
Calculator identified "medium" channel susceptibility with 0.3Q2 for each reach. Therefore, the
SCCWRP channel screening analyses and the San Diego BMP Sizing Calculator show that the
HMP analyses can be modeled using 0.3Q2-
Prepared By: JJT:JMC:vs/Reporti17169.001
Rick Engineering Company - Water Resources Division 11-24-14
5
APPENDIX A
Geomorphic Assessment Results
- San Diego BMP Sizing Calculator Results
- Initial Desktop Analysis Results
- SCCWRP Vertical Susceptibility Results
- SCCWRP Lateral Susceptibility Results
- SCCWRP Probability of Mass Wasting Results
Prepared By: - JJT:JMC:vs/Reportl! 7169.001
Rick Engineering Company - Water Resources Division 11-24-14
S. CA Hydromodiflcation Screening Tool version 1.0
user: iciranerickenaineerinci .com j stream: Reach I - Channel Upstream of POC
latitude (decimal degrees): I 33.12321
longitude (decimal degrees): I .117.26331
FORM 1: INITIAL DESKTOP ANALYSIS
GIS metrics and screening Indices (for detailed instructions/examples see 'Field Screening Companion Document')
Symbol Variable units Value Descriotion & Source
A Drainage Area .2 ml 0 01 I 1
contributing drainage area to screening location via published HUCs and/or 30-rn (or better) National Elevation Data
(NED), USGS seamless server
Mean annual inches I 142 area-weighted annual precipitation via USGS delineated polygons using records from 1900 to 1960 (which was more
precipitation significant in hydrologic models than polygons delineated from shorter record lengths)
_____ valley slope at site vie NED, measured over a relatively homogeneous valley segment as indicated by slope, hi/Islope
Valley slope rn/rn 1-0.038 I coupling/confinement, valley alignment, confluences, etc., over a distance of up to -500 meters or 10% of the main-
channel length (whatever is smeller)
_________ valley bottom width at site between natural valley walls as dictated by clear breaks in hilislope on NED rester,
WV Valley width meters 23 I irrespective of potential armoring from floodplain encroachement, levees, etc. (imprecise measurements have
negligible effect on rating in tde valleys where VWI 3>2, as defined in lateral decision tree)
flow, US units ft3/5 I 311 Qo = 16.2 * A 0-87 - P°77 (Hawley and Bledsoe, In review)
010 10-year peak m3/s I - 0.0711 Q 0 = 0.0283 * Qlocfs flow
INDEX 10-year mobility
index m1'5/s°5 I' 0.01011 INDEX =
W Reference width meters I 2.21I W= 6.99 * 010 0438
VW
Valley width rn/rn I 1040'I 'IWl=WlW rW index
. - - - 4- 1 . I .... - L I - I -
S. CA Hydmmodification Screening Tool version 1.0
user IicronerickenQ1neerin corn j stream: Reach 2 - Channel Downstream of POC
latitude (decimal degrees): I 33.12321
longitude (decimal degrees): I -1172633
FORM 1: INITIAL DESKTOP ANALYSIS
GIS metrics and screening indices (for detailed instructions/examples see 'Field Screenina Companion Document')
Symbol Variable mob Yalu Description & Source
A ra age ea Drainage Area mi 29 •
'
contributing drainage area to screening location via published HUCs encbbr 30-rn (or better) National Elevation Data
(NED), USGS seamless server
Mean annual inches 2 area-weighted annual precipitation via USGS dehneated polygons using records from 1900 to 1960 (which was more
precipitation I 1 significant In hydrologic models then polygons delineated from shorter record lengths)
valley slope at site via NED, measured over a relatively homogeneous valley segment as indicated by slope, hillslope
S, Valley slope rn/rn J 0.0244 I coupling/confinement, valley alignment, confluences, etc., over a distance of up to -500 meters or 10% of the main-
channel length (whatever is smallei
valley bottom width at site between natural valley walls as dictated by clear breaks in hillslope on NED taste,;
W,, Valley width meters I 23 I irrespective of potential armoring from floodplain encmechement, levees, etc. (imprecise measurements have
negligible effect on rating in wide valleys where t'W >>2. as defined in lateral decision tree)
l0CfS
10-year peak
flow, US units
-
- 48 1 I 777-48-1 087 017 010d, = 18.2 • A P (Hawley and Bledsoe, In review)
Q10 10-year peak m3/s I. .1;35I 010 =0.0283Q1 flow
INDEX 10-year mobility m15/s05 - :0.O28I INDEX = * 0,0 0.5
index
W Reference width meters I - 7.98 I WWf = 6.99 * 0.438
VWI Valley width rn/rn r---2—.8-81 I VWI = WV! W, index
- -- c- t:-i
ki
S.CA Hydromodification Screening Tool version 1.0
user: icironerickenineerinQcom
latitude (decimal degrees): I 33.1232]
longitude (decimal degrees): F-11-7.-2-633-1 -117.26331
Reach 3 - Channel Downstream of POC
FORM 1: INITIAL DESKTOP ANALYSIS
GIS metrics and screening Indices (for detailed Instructions/examples see 'Field Screening Companion Document')
Symbol Variable units Value [$CriDtiOn & Source
A Drainage Area g mi 2 03 contributing drainage area to screening location via published HUCs and/or 30-rn (or better) National Elevation Data
. I (NED), USGS seamless server
Mean annual inches 14 2 area-weighted annual precipitation via USGS delineated polygons using records from 1900 to 1960 (which was more
precipitation • significant in hydrologic models than polygons delineated from shorter record lengths)
valley slope at site via NED, measured over a relatively homogeneous valley segment as indicated by slope, hilislope
S, Valley slope rn/rn I 0.0244 I coupling(conhinement, valley alignment, confluences, etc., over distance of up to -500 meters or 10% of the main-
channel length (whatever is smeller)
valley bottom width at site between natural valley walls as dictated by clear breaks In hillslope on NED raster,
WV Valley width meters I 23 I irrespective of potential armoring from floodplain encroachement, levees, etc. (imprecise measurements have
negligible effect on rating in wide valleys where VWI >>2, as defined in lateral decision tree)
Owcis 10-year peak ft3/s I .4911 Q 18.2 * Aoe7 * P 0 (Hawley and Bledsoe, In review) flow, US units
Q10 10-year peak m3/s 010 =0.0283*Q1
flow
INDEX 10-year mobility m'5/s r-770-.-02-91! 0.029! INDEX = S • Qio 0.5
index
W Reference width meters r-77 '8.08r1 W,: 6.99 Q10 0.438
VWI Valley width rn/rn I 25j WVI = W,i W,, index
-
Basin Characteristics Report
Date: Wed Dee 19 2012 10:18:35 Mountain Standard Time
ND27 Latitude: 33.1217 (33 07 18)
NAD27 Longitude: -117.2607 (-117 15 39)
I1AD83 Latitude, 33.1217(330718)
NAD83 Longitude -117.2616 (-117 15 42)
Irt
ArGa, in square miles
mean annual precIptatn. in
11 I Ib • .,.1 4 — 4 1, S S #'.44a...I q - •q 1% — I -
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
. -,b-. -..
StreamStats Print Page
Bressi Ranch
Ex.Iasaiu
GIlWflrWsd'iir
Cenorod
- .2E.WdePcPy
skearns
• nUisUc S,eanG h1 U
I Glowlialienitrad
• anS4 Continuous R,co1C •
LOwFIOw, PtidIctwd
-: £ Peak Flea,. ParflRscatd
Peak and Flea Portia Peco,d
-
• £ stwonw
: A Lw Flow, Portia lRecord, Slave
A Mlkcee.AIGUSF.c3rd
A UnImown
"LA
112/19/2012 1023:00 AM
r
SC ?uomodiIIcas1in $a-eou5ip Tool veouoo 50
oI 5ioI Ifruom: Roucfri -iomis Du..dPOC
la58tde:Io3s.i25
longftd.. -IIT.2131 -
FORM 3: PEBBLE COUNT & MOBILITY INDEX THRESHOLD
Fabbi. Counf ifs is ouceosuylo .othnolo d50 p.1Mm a peStle COunt oOtg a n5nlmw,, us 100 peSStos aSS a stin4aodplS template ubymeaunmg olovig Si. titaim.frafe &xio
god AVIE Aing 01.8th pebble. 08.8 01W and lape ft'snten,atlebonlele fraSnects aemes 0.18 eecfronn fr,, Ott. tb psi is in Si. nildift cl.bieanct ouop11M15.
'L P_i_ MO'aanod toMe nt.15805 Iii. COoS). ffMee (sardStt) amsano 18.8 M4nth 2 I I 21 CiSt(- an blifetaebt) olpthitulnanple. aemapatate to sample Si. 3 I 21 esomer beStS euWtat.. ottienrne moods. obserasbon of Ones (L a 2 net, 4!3I2) rned.dbiapmadsft.efaa2nw,, T.topliticprs,oh, toouppolteie,esults.
514 _21
8!5 _21
7
Ii 7 _2
8 8 I_21 I0ftI 21 total idols.
11 EI
12 M
I Ion
131 7 2 moblittylridsa ,nublbtyluds. ICOIIMeI
14 6 2, 8O ° cpondteftto BmWmg
16 18 I Risk IS 4 2:MW lJ rw
'? ?LLLJ
Based upon field reconnaissance soil particles for each
N
re observed to be less than 2 mm therefore
le count diameter is input as 2mm.
Pebble oo(mf Shea 8, eS, loOP, SI, Si. loft we .omI. data Sw
V1Iib8.fr, pwpuus oes. You mijst,eplic. taos. dot. .60, is pebble colaS die, from yoorllstl site. Onc.popolat.d OW pebble colaS remote 1860 be Used ft aidwne5o16y popalOW flaSa an Poem 2 and Porn, 4.
[
Section 6 Hydromodificaon Management Plan
REACH 1/ REACH Z/ REACH 3
SCCWRP VERTICAL SUSCEPTIBILITY DECISION TREE
Figure 6-4
Figure
6-2
CHANNEL BED RESISTANCE
LABILE BED I COARSE/ARMORED BED __ 'Sand-dominated I .d50>126mm
(15 < 16 mm I a k d • Boulder flarge cobble I • % surface sand> 25% Her pan o u ce In lightly-packed 'Loosely-packed a ejte bi • .c5% sand
Continuous bedrock
Continuous concrete
Grade control nt, LOW EXAMINE RISK d \NO grade control Form Checklist
#HIGHH
E:Checklist2bility of
i7
incisionHIGH pe I Form 3: Figure 4
checklists
go to bed erodibility
and incision
Y HIGH diagram check list
FU out SCCWRP scoring I criteria to determine If the I. channel has a HIGH, ~ See Attached
LOW susceptibility
VERY I I HIGH HIGH IIMEM 131 LOW
Go to
Figure ~ Lateral Susceptibility
6-5
Figure 64. SCCWRP Veitical Susceptibility
REACH 1I REACH 2/ REACH 3
Form 3 SUDDort Materials
Form 3 Checklists I and 2, along with Information recording in Form 3 Table 1,
are Intended to support the decisions pathways illustrated in
Form 'S Overall Vertical Rating for lntermediatelTransitional Bed.
Form 3 Checklist 1: Armoring Potential
A A mix of coarse gravels and cobbles that are tightly packed with <5% surface material or diameter <2 mm
X B Intermediate to A and C or e, spatial extent
(longitudinal and depth), orM
ervetreMncounere Mwiprobe
due tc surface
veneer covering gravel or co
C Gravels/cobbles that are loosely packed or >25% surface material of
diameter <2 mm
Form 3 Figure 2. Armoring potential photographic supplement for assessing intermediate beds
(16 < dw <128 mm) to be used in conjunction with Form 3 Checklist 1.
I
I
I
I
I
I
I
I
I
1
I
I
I
I
I
I
I
I
I
Figure 7 Continued
ARMORING NUMERIC VALUE: B=6
•* * t* & S. *** * ** 5*55*5 5* 5*5*5* *5
17
REACH 1/ REACH 2/ REACH 3
I
Form 3 Checklist 2: Grade Control
A Grade control is present wllh spacing <50 m or 2/S. m I D
No evidence of failureAneffectivenass, e.g.. no headculting (>30 Cm), no
active mass wasting (analyst cannot say grade control sufficient it mass.
wasting checklist Indicates presence of bank failure), no exposed bridge
I llings, no culvert s/structures undermined
-lard points in serviceable condition at decadal lime scale. e.g., no a)parenl
indermining, flanking, railing grout
I . f geologic grade control, rock should be resistant igneous and/or
metamorphic; For sedimentarylhardpan to be classified as 'grate control', It should be of demonstrable strength as indicated by field tes:ing such as
I iammer lestlborings and/or Inspected by appropriate stakeholder
B In X ennediate to A and C - artificial or geologic grade control
herd an 4ISv m or potential evidence of failure or f
9;rlain resislanc I n C Grade control absent, spaced >100 m or >4/Sw rn or clear evidence
of ineffectiveness
I
I
I
I
1
I
I Form 3 Figure 3. Grade-control (condition) photographic supplement for assessing intermediate beds (16 < dw < 128 nnl to be used In conjunction with Form 3 Checklist 2.
I LLn'-!,
CONTROL NUMERIC VALUE: B=6
**** a..tt...ttn***t***aa***
Figure 7. Continued
I
I 18
I
I REAC-I 1/ REACH 2 / REACH 3
I
I Regionally -calibrated Screening Index Thresho d for Incising/Braiding
For transitional bed channels (dN batwsen 16 and 128 mm) or laolle beds (channel not ircised
past critical bank heigh:) use Form 3 Figure 310 determine Screening Index Score and complete
1
Form 3 Table l.
1 -.
I 0.1
:: : .
I Q 0.01 E 80 0.114
cc 64 0101
0,001 48 0.087 1 0.1 1 d (mm) 10 100 0 32 0070
16 0.049 . aable Braided - Incising 8 0.031 D% risk - 50% risk 90% risk I i
Ill •c 4 0.026
2 0.022
!:3 Field-derived:d.5 (I 00-pebble count) 0 , 1 0.018
1
IF 0.5 0.015
Form 3 Figure 4. Probability of incising/braiding based on logistc regression of Screening Index
and (6 to be used In conjunction with Form 3 Table 1.
I
Form 3 Table 1. Values for Screening Index Threshold (probabll.ty of incising(braiding) 10 be used
In conjunction with Form 3 Figure 4 (above) to complete Form 3 Overall Vertical Rating for
IntermedIate/TransItIonal Bed Itielo A . c e 1 I e o c50% probability of cisbn I for current Q, valley slope, and d B = ar pan! In e ermlnate and C =50% probabllit'i of
incising/braiding for current 010, vail
I d (mm) SQ1003 (m'!s°6) VOW"(m'Is°5
50% risk of incisingiixiding Screening Irdex Score
From Fm 2 Froi Fci-m I (A, B C)
I SCREE ING INDEX SC RE NU~ERICV~~ E'.B=6
Overal Vertical Rating for Intermediate/Transitional Bed I Calculate the overall Vejical Rating for Transitional Bed channels using the formula below.
Numeric values for responses to Form 3 Checklists and Table I as follows: A = 3, B -6, C -9.
I Vertical Rating = ,J[(iarmoring grade control) sreenin9 index score)
I
Vertical Susceptibility based on Vertical Rating: 0.5 = LOW; 4.5 to 7 = MEDIUM; and >7 = HIGH.
VERTICAL RATING [(6 x 6)A(1/2) x 6j(1/2) = 6
F. Figure 7. Continued VERTICAL SUSCEPTIBILITY MEW UM
I
1 19
I
no
yes
es
no yes
FORM 5: SEQUENCE OF LATERAL SUSCEPTIBILITY QUESTIONS OPTION
Enter Lateral Susceptibility (Very High, High, Medium, Low) in shaded column.
Mass wasting and bank instability from Form 6, VWI from Form 4, and Vertical Rating from Form 3.
Lateral Susceptibility
Channel fully, confined with VWI —1— connected hillslopes If YES,
OR fully-armored/engineered bed and banks in good then LOW
condition?
IfNO, If YES,
Is there active mass wasting or. extensive fluvial erosion VWI:52= HIGH,
(>50% of bank length)? VWI>2 = VERY HIGH
- -.-
thariy risk factors present?
Risk Factors:
I o ,$iabIlity p> 10% • All three = VERY HIGH
ating?High
If. NO,
Are banks either consolidated or unconsolidated with coarse
toe of d >64 mm? Risk Factors:
VWI>2 Two = HIGH
Vertical rating ? High • One = MEDIUM
None = LOW
- -- - . - - - -- -. . - - -- -. - -- -- - -- .. r-,- ,rr ...e...,.,t -I--r --.*P. - .-.--,t •..,
If NO, How many risk factors present?
At least one bank is unconsolidated with toe of d <64 mm Risk Factors:
VWI>2 • Two = VERY HIGH
Vertical rating High • One = HIGH
None = MEDIUM
(Sheet 1 qf/)
If YES,
How many risk factors present?
Figure 13. Form 5: Sequence of Lateral Questions Option for lateral susceptibility assessment. Complete set of assessment forms in
Appendix B.
25
REACH 1/REACH 2/REACH 3
FORM 6: PROBABILITY OF MASS WASTING BANK FAILURE
If mass wasting is not currently extensive and the banks are moderately- to well-consolidated, measure
bank height and angle at several locations (i.e., at least three locations that capture the range of
conditions present in the study reach) to estimate representative values for the reach. Use Form 6 Figure
I below to determine if risk of bank failure is >10% and complete Form 6 Table 1. Support your results
with photographs that include a protractor/rod/tape/person for scale.
Bank Angle Bank Height Corresponding Bank Height for Bank Failure Risk
(degrees) (m) 10% Risk of Mass Wasting (m) (00% Risk) ffn,m ,Ciøjdl Ifrnm FMMI (fri-un ItmI A FievitrA I /, IML DI
Right Bank
1..00 9
30 7.6
• £ S SI £•
f
35 4.7 0 Stable - - 10% Risk 50% Risk - 90% Risk X Unstable
4 x 40 3.7
45 2.1
L 3 100 'X\' X X 50 1.5
— \ X 55 11
L 2
X
Je OAS :: 0.66
000O X 70 0.52
2 00
1io0 X 80 0.34
1.
0 00 90 0.24 I o(bCD 0 0 d'O-*
30 40 50 60 70 80 90
Bank Angle (degrees)
Form 6 Figure 1. Probability Mass Wasting diagram, Bank Angle:Height!% Risk table, and
Band Height:Angle schematic.
(Sheet 1 of 1)
Figure 14. Form 6: Probability of Mass Wasting Bank Failure for lateral susceptibility assessment.
Complete set of assessment forms In Appendix B.
26
Vertical Medium (Vertical) Susceptibility:
Lateral Susceptibility: Medium (Lateral)
£7
Material: Vegetation •
Roughness: 0100
Channel Top Width (0*): 112.0
Channel Bottom Width (ft}; 10.0
Channel Height ((0): 11.0
Channel Slope: c.021
Channel
Assessed: Yes
Watershed 154 55 Area (ac)
I
REACH 1- CHANNEL UPSTREAM OF POC
I
I
I
I
Define Drainage Basins Dress) Ranch
U LP01,f I
Manage Your Point of Compliance (POC)
Analyze the receiving water at the Point of Compliant: by completing _________________
this turin Click di1 and enter the approxrale fields lien click the Channel Susceptibaily: It4)lkt Update eilton to calculate the critical flow and low-fo'iF threshold ______________ condition Finally click Save to commit the changes Low Flow Threshold: 10 302
Wl• fiVl I!1
wlcu Bressi Rancl
Assessed: se
Charnel
SJ.ceptibility: Vertical Medium Vsrticl)
Watershed j 01 Lateral Medium Lateral) Area (Sc): I Siiacepilblllly:
Material: Vegetation - r
Roughness: 0100
Channel Top Width (fe: 12.0
Channel Bottom Width III): 10.0
Channel Height (II): 1.0
Channel Slope: lo.03
REACH 2-CHANNEL DOWNSTREAM OF POC
Define Drainage Basins Breasi Ranch l'rcti Bress Ranch
U U LocJ J
Manage Your Point of Compliance (POC)
Analyze the tCCMfl9 water at the t'eint of Compliatoe by completing
this forts Click Edit and enter the appropnate fields, then click the Channel Susceptibility: IMEDIUM Update button to calculate the critical flow and 10w1131if threshold __________________ condition Finally. cluck Save to commit the changes Low Flow Threshold: O 3(32
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Vertical Medium (Venicet) - Susceptibility:
Lateral
Susceptibility: Medium (Lateral)
Matertal: Vegetation
Roughness: [0.100
Channel Top Width (fi): 12.0
Channel Bottom Width (II): 10.0
Channel height lh) 11.0
Channel Slope:
Channel Ye. Aaasu.d
Watershed
Area (ac):
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
REACH 3—CHANNEL DOWNSTREAM OF POC
Define Drainage Basins Bressi Ranch
I
Manage Your Point of Compliance IPOC)
Analyze the receMng water at the Point of Compliance by completing
this form Click Edit and enter the appropriate felds tnen click the Channel Susceptibility: IMED(tM
Update button to calculate the critical low and low-low threshold ___________________ condition Finally click Sam to commit the changes Low Flow Threshold: ro.3Q2
BressiRarich
APPENDIX B
Geomorphic Assessment Exhibits
Prepared By: -- JJT:JMC:vs/Report/17169.00!
Rick Engineering Company - Water Resources Division 11-24-14
I
I
I
I
I
[1
Li]
~7,
I
I
[1
I
I
I
I
I
LI
0
BRESSI RANCH - GEOMORPHIC ASSESSMENT
I Exhibit Date: November 24, 2014 0 250 500 1,000 Data so
Filepath: J :\1 6666\GS\16666_GA mxd
IBM ____________ SanGIS Roads - February 200
I Feet REC JN: 17169 Aerial Photo March 2009
2010 California 303(d) List of Water Quality Limited Segments*
Water quality limited segments requiring a TMDL(5A), being addressed by TMDL)5B), endlor being addressed by an action other than TMDL(5C).
RegionalSoarsIi - SanDiegoRegion ban Marcos creek louiuju-1 5u431000 19 Miles tIDE(DichlnrodiphenyldichlnroethyliPesticides Liston303(d) list (TMDLrequiredlist) 5A 2019
Regional Boa rd9-SanDiegoRegion 'tanMarcos Crook 18070303 90451000 19 Miles Phosphorus Nutrients List on303(d)list )TMDLrequiredlist) 5A 2019
RegionalBoard9-SanDiegoRegion San Marcos Crook 18070303 90451000 19 Mites Phosphorus Nutrients ston303(d)list)TMDLrequi
'a
d list)
12
5A 2019
RegionalBoard9- San Diego Region San Marcos Creak 18070303 90451000 19 Miles Phosphorus Nutrients .t st on303)d)list 5A 2019
RegionalBo and 9- San Diego Region San Marcos Creek 18070303 90451000 19 Mites Phosphorus Nutrients List on303(d)list (TMDL required list) BA 2019
Regional Board 9- San Diego Region 'tanMarcos Creek 18070303 90451000 19 Miles Sediment Toxicity osicity Do Not Delist from 303(d) list )TMDL required list) 5A 2019
Reg ionalBoardS-SanDiegoRegion IanMarcosCreek 18070303 90451000 19 Miles Sediment Toxicity oxicity DoNotDelistfrom303(4)list)TMDLrequiredlist) 5A 2019
Reg ion alBoard9-SanDiegoRegion 'tanMarcosCreek 18070303 90451000 19 Miles 'edioment Toxicity noicity DoNotDelislfrom303(d)list )TMDLrequiredtnt) 5A 2019
RegionalBoard9-SanDiegoRegion SanMaroosCreek 18070303 90451000 19 Miles Selenium Mrdals/Metalloids st 00303(d)list (TMDLrequiredlist) 5A 2021
I
I
I
I
1
I
I
I
I
I
I
I
I
I
I
I
I
I
I
ME
BASIN B
PTA?1 0101!
ffsin A A-I A-! _rAt3
S - -
Basin n L_"
s-s L
cS]
L1
liasi ii I)
0-1 %. 0-1 D-3 0-4
1
F 11 (-2 1-4
S -
wilm v)mI2.
I6 TO I4
30 TO 4V
ADM 4V
VMH
nwvm STOSM 0220102 *101001 FA2TT
IA. RIMERM OR POlIO
XWER CU 1102011
Basin A BtIOA TATEmm
Basin B 2GUAOlIO21
Basin C c WA
Basin D 22*lITOU TA
IA1 CUIOJ
BM PA2TY DJW1O2 rawt Mt I. BlN 0111140101 the
PROPOSED PIANNED 02004002 (2W) AM 022*1RT
4— 11IE&1I 2001*40 CUA11
POWOM 1112211011 IATUROL 02*10411.
4— N0101 com PIV
10
00FM 011111111122201
I..' P2010l 211IITATI0?4 20111
o TD1G MCMIUMIATION 50*71
IOTT 01 U&*2200 SOUN202Y
APPENDIX C
Field Photographs
Prepared By: JJT:JMC:vs/RcporL/17 169.001
Rick Engineering Company - Water Resources Division 11-24-14
I
I
I
1
1
I
I
I
I
I
I
I
I
I
I
I
I
I
I
•q
4.;•iAlIii ;•
It',' , : 4• '-•
--- *
Photograph 1: Existing Detention Basin and Concrete Overflow
Photograph 2: Storm Drain Outlet at Alicante Road
I
I
1
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Photograph 3: (Reach 2) Top of Left Bank Looking Downstream - Densely Vegetated
.\ 't::yi• • ,;..
Photograph 4: (Reach 2) 35-40 Feet Left of Thaiweg - Densely Vegetated
IF
I
Xf
I L ç :
I
:-'I. •s:.r••.
I
I
1
1
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Photograph 7: (Reach 3) Top of Left Bank Looking Downstream - Densely Vegetated
11 j
i At
Photograph 8: (Reach 3) lhalweg of Channel
I
I
I
Photograph 11: Lentic Waterbody— Habitat Conservation Area (15-ft Tall Reecs)
#r
I
I
Photograph 12: (Reach 1) Top of Right Bank Looking Downstream - Densely Vegetated
I
I
I
I
I
I
I
I
I
I
I
I
I
I
- :
:
e. - •-:' s... L \ -!1 t±E41 - b
/ \
-.-
: