HomeMy WebLinkAbout; Coastal Storm Drain Study; Coastal Storm Drain Study; 1984-04-01/ WILSON ENGINEERING
DEXTER S. WILSON
COASTAL STORM DRAIN STUDY
City of Carlsbad
April 1984
Wilson Engineering
Vista, California
E. VISTA WAY VISTA, CALIFORNIA 92083 (619) 758-2093
Table of Contents
Page
Report Summary 1
Chapter 1 Introduction / Scope and Area of Study . 4
Chapter 2 Description of Existing Facilities ... 5
Chapter 3 Bluff Erosion 38
Chapter 4 Needed Repairs 41
Chapter 5 Master Facilities 45
List of Tables
Page
2-1 Summary of Subareas 6, 7
4-1 Needed Repairs to Existing Drains 43, 44
5-1 Summary of Cost for Master Drainage System . . 46, 47,
48, 49, 50
List of Figures
ES-1 Coastal Storm Drain Areas
5-1 through 5-4 Master Drainage Facilities .
Page
2
At Back
of Report
Report Summary
The storm drains serving the beach area of Carlsbad were
neither designed nor constructed systematically. Each drain
collects water from a small area and carries it directly over
the bluff and onto the beach. Due to the steep slope of the
drains descending the bluff, drain failures cause severe
erosion. If the present system of drains is not replaced,
periodic failures and the concomitant erosion should be
expected.
This study breaks coastal Carlsbad into five separate
strips, from north to south, labled Areas A through E. The
Areas are shown in Figure ES-1. A discusson of each area
follows.
Area A
Area A extends from the Buena Vista Lagoon weir on the north
to Oak street on the south. In this area buildings extend from
the top of the bluff to the beach area. Bluff erosion is not a
major concern because nearly all the beachfront land in this
area has been developed.
During the winter of 1984, the city improved two of the
drains in this area. All of the drains should now be adequate.
The only improvements currently needed in this area are curb and
gutter to eliminate nuisance puddles and provide a course for
water to reach the existing drains.
Area B
All land adjacent to the ocean in area B is part of the
state park system. Area B extends from the parking lot south
of Oak Avenue to the Agua Hedionda Lagoon bridge. This area is
known as the Whale Watch area.
Area B contains fifteen storm drains, which are spaced
closer together than those in any other area is Carlsbad.
There have been many drain failures in this area and there will
continue to be failures in the future.
To minimize erosion, the present Area B system should be
replaced with a single drain parallel to the ocean. This
parallel drain would cost $572,000. To repair the existing
drains to original conditions would cost $187,000. If the
drains were repaired to original conditions future failures
could be expected due to wave action.
R
I
COASTAL STORMDRAIN
AREAS
Area A
1
1
1
i
Area B
Area C
i
1
1
Area
WILSON ENGINEERING
FIGURE ES- I
Area C
Area C, known as the Terra Mar area, extends from the power
plant outlet at the south end of Agua Hedionda north to Cerezo
Drain. This area contains very few storm drains and, like
Area A, is developed with single family homes constructed on
the bluff.
The storm drains in the developed area west of Carlsbad
Boulevard are adequate. However, a master drainage system is
needed for the areas east of Carlsbad Boulevard and for portions
of Area D (see below) which drain north through Area C. To
construct a master drainage system to serve this area would cost
$495,000. To repair the existing drains to original conditions
would cost $7,500. Even with repairs to original conditions,
future drain failures could be expected.
Area D
Area D extends from Cerezo Drive south to the Encinas Creek
Bridge. All land adjacent to the ocean in this area is part of
the State Park System. The state land has not been improved for
use as a park. Beach access is difficult and, in some areas,
impossible. The storm drains in this area are all old with no
evidence of recent repairs.
A master drainage system should be installed in this area
when it is developed as a park. Eliminating the present system
and replacing it with a single drain parallel to the ocean
would cost $206,000. To repair the existing drains to original
conditions would cost $237,500. Repairing the drains to
original conditions would not prevent future failures. Some of
the drains in this area serve only state park land.
Area E
All land in Area E adjacent to the ocean is part of the
State Park System, and is entirely developed as a campground.
Area E extends from Encinas Creek on the north to Batiquitos
Lagoon on the south. The bluff in this area is quite high and
all access to the beach from the campground is by stairs. This
is the only area containing storm drains larger than 18",
although it also contains many smaller undersized drains. There
has been substantial erosion from some of the smaller storm
drains, but the larger drains have caused little erosion. Most
of the smaller drains serve only state park land.
To eliminate the present area storm drains and replace them
with a master drainage system would cost $1,264,000. The master
drainage system for -this area would require two major drains,
one serving the northern half of area E and one serving the
southern half. If the drains in this area were repaired to
original condition it would cost $97,000 and future failures
could be expected.
-3-
Chapter 1
Introduction / Scope and Area of Study
This report evaluates the existing Carlsbad coastal storm
drains, including a listing of repairs needed to existing
drains, an identification of existing drainage basins, and the
development of a master coastal drainage system.
The area of study is bounded on the north by Buena Vista
Lagoon, on the south by Batiquitos Lagoon and on the west by
the ocean. The easterly boundary of the study area is set by
drainage. All drainage basins which enter the ocean directly
are addressed in this report.
A portion of this report will also be dedicated to bluff
erosion and the design of future storm drains to limit erosion.
-4-
Chapter 2
Description of Existing Facilities
Coastal Carlsbad has been divided into five major drainage
areas for the purposes of this study. These five areas were
further divided into various gravity drainage subareas. -The
following pages describe the five major areas and provide a
description of the facilities serving each subarea. Table 2-1
lists the area, outlet pipe size, 100-year storm flow and outlet
pipe capacity for each of the subareas.
Area A
Area A extends from the weir on Buena Vista Lagoon on the
north to Oak street on the south. In this area there are
buildings extending from the top of the bluff to the beach
area. Bluff erosion is not a major concern in this area
because nearly all the beachfront land in this area has been
developed. Erosion from both wave action and storm drains at
times endangers structures and thus property owners in the area
must take preventative measures to protect the structures. The
old storm drain facilities on the roads above the bluff were
inadequate. At the present time construction is underway to
install new storm drains to convey water from the roads to the
beach area. This, however, will not solve all the problems.
The roads in this area do not have curb and gutter. After
rains, the water tends to puddle along the edge of the roads
and only the overflow from the puddles is able to flow along
the roads and into the storm drains. The new storm drains will
not improve the situation since the water still will not be
able to make its way to the drains. The puddles are a consider-
able nuisance in the area and we recommend that a program be
developed to install curb and gutter in this area.
There are approximately 25 acres in area A. The 25 acres
are broken into 4 subareas 7and these 4 subareas are described
below.
A-l This subarea contains 2.7 apres. It is served by
an 18" PVC (Polyvinyl Chloride) outlet pipe with
0-ring joints which was installed during the
winter of 1984. One inlet serves this subarea.
The pipe runs to the beach at the north end of
Ocean Street, adjacent to the beach access stair-
ways. The majority of this subarea has curb and
gutter.
A-2 This subarea contains 9.9 acres. It is served by
an 18" AC (Asbestos Cement) outlet pipe which was
installed during the winter of 1984. Two inlets
serve this subarea. The pipe runs to the beach
at Cypress Avenue.
-5-
i
I TABLE 2-1
SUMMARY OF SUBAREAS
i Area/Subarea
9™5S
A 1
1
__ 3
1
IB Totals
1 B 1
i
. • 3
|| w 4
t
M - 51
•8
1
Totals
1 C 1
• 2
^ 3
1BMJ
5
1 . Totals
Acres
2.7
9.9
9.5
2.9
25.0
6.0
4.7
3.3
3.4
7.9
5.8
5.0
12.8
1.0
49.9
2.1
14.9
3.8
3.8
3.0
27.6
Flow Generated
(CFS)
@ 2.5 CFS/Acre
6.8
24.8
23.8
7.3
15.0
11.8
8.3
8.5
19.8
14.5
12.5
32.0
2.5
5.3
37.3
9.5
9.5
7.5
Outlet
Pipe Size
and Type
18" PVC
18" AC
18" AC
12" CMP
Varies
Unknown
18" PVC
18" PVC
18" AC
18" PVC
12" CMP
Overland
Varies
Varies
Overland
18" RCP
V-ditch
Unknown
Outlet
Capacity
(CFS)
26.5
26.5
26.5
- 7.9
_ _ _
?
26.5
26.5
26.5
26.5
7.9
_ _ _
_ _ _
- - -
_ _ _
26.5
- - -
_ _ _
oUndersized
Pipe
Capacity/<18"
<18"
<18", CAP
1
-6-
TABLE 2-1
SUMMARY OF SUBAREAS (continued)
I o
^ Area/Subarea
I
I
D 1
I 2 SP
1 3
" 4
1 5
3
6
^A
• 8
* 9
| Totals
: E i
1 2SP
^}
•
1 4
B 5
6SP
I
8 8
1 9 SP9
10
llsp
n Totals
Acres
12.9
7.4
1.3
.7
4.3
1.3
.9
1.3
.5
30.6
.9
2.6
1.7
14.9
2.7
3.5
4.3
37.9
1.7
69.5
1.1
140.8
Flow Generated
(CFS)
@ 2.5 CFS/Acre
32.3
18.5
3.3
1.8
10.8
3.3
2.3
3.3
1.3
2.3
6.5
4.3
37.3
6.8
8.8
10.8
94.8
4.3
173.8
2.8
Outlet
Pipe Size
and Type
18" RCP
Varies
Unknown
12" CMP
18" CMP
18" CMP
18" CMP
18" CMP
Overland
18" CMP
8" PVC
8" PVC
24" CMP
8" CMP
8" CMP
8" PVC
24" PVC
Overland
30" CMP
Overland
Outlet
Capacity
(CFS)
26.5
_ _ _
?
7.9
26.5
26.5
26.5
26.5
_ _ _
26.5
3.5
3.5
47.1
3.5
3.5
3.5
47.1
_ _ _
73.6
_ _ _
oUndersized
Pipe
Capacity /< 18"
CAP
<18"
<18", CAP
<18", CAP
<18", CAP
<18", CAP
<18", CAP
CAP
CAP
CAP in this column indicates that the existing pipe has insufficient
capacity to serve the drainage basin. <18" indicates pipe is smaller
than the minimum recommended size of 18".
indicates drains that begin and end on State park land.
-7-
A-3 This subarea contains 9.5 acres. It is served by
an 18" AC outlet pipe. This pipe was installed
currently with the construction of the adjacent
hotel in the 1970's. Three inlets serve this sub-
area. The pipe runs to the beach at Christiansen
Way, adjacent to the beach access stairway.
A-4 This subarea contains 2.9 acres. It is served by
a 12" CMP (Corrugated Metal Pipe) outlet pipe.
This pipe was probably installed in the 1960's.
One inlet serves this subarea. The pipe runs to
the beach at Elm Avenue, adjacent to the beach
access stairway. This drain may need replacing
in five to ten years.
Area B
All land adjacent to the ocean in area B is part of the
state park system. This area extends from the parking lot south
of Oak Avenue to the Agua Hedionda Lagoon bridge. This area is
known as the Whale Watch area.
There are a large number of storm drains in this area
There are several generations of storm drains, some of which
are abandoned. As development proceeded in this area new storm
drains were installed and the old ones were either abandoned in
place or utilized to carry water from smaller areas. Bluff
erosion in this area is substantial. Two storm drains in this
area were replaced and repaired this winter by the City when
erosion threatened Carlsbad Boulevard. In this area all the
drains have a very steep slope as they leave the roadbed and go
over the bluff. This area also has heavy foot traffic over the
slope. Both of these factors contribute to erosion in the area.
Although there are a large number of storm drains in this
area, there does not appear to be a uniform drainage system.
Each pipe serves a small area and nearly every pipe has caused
bluff erosion. This is an area which has needed and will
continue to need emergency repairs as storm drains fail. A long
term drainage solution is badly needed in this area.
This area contains approximately 50 acres, and 9 subareas.
The majority of the major drains in this area seem to have been
installed concurrent with adjacent road improvements.
B-l This subarea contains 6.0 acres. It is served
by two separate corrugated metal pipes. One of
the drains has a single inlet and serves only a
small area on the west side of Ocean Street.
The other drain has two inlets and serves the
majority of the area. Both drains have 12"
outlet pipes. The age of these pipes is
undetermined. Both pipes enter the beach area
from the parking lot along Ocean Boulevard
-8-
between Oak and Pine. Repairs are urgently
needed in this subarea because one of the drains
has begun to undercut the parking lot. Both
drains are shown in pictures below.
o
2
<D
•9-
B-2 This subarea contains 4.7 acres. It is served by
a single corrugated metal pipe, but the outlet
could not be found due to a heavy growth of
bamboo. It has two inlets, one on each side of
Pine Avenue at Carlsbad Boulevard. The age of
this pipe is undetermined. Repairs are urgently
needed at the outlet due to.bluff erosion. The
bank appears to be supported by the bamboo
growth. This pipe drops to the beach at Pine
Avenue.
B-3 This subarea contains 3.3 acres. It was origi-
nally served by a 15" RCP pipe. The outlet pipe
was repaired and eroded bluff replaced in the
winter of 1984. The pipe material used for
replacement was PVC with 0-ring joints. This
pipe has two inlets, one on each side of Walnut
Avenue, and reaches the beach at an extension of
Walnut Avenue. The repaired pipe is shown below.
-10-
1
B-4 This subarea contains 3.4 acres. The pipe is fed
by two inlets, one on each side of Sycamore
Street, and it drops to the beach at Sycamore
Street. The outlet area was repaired during the
winter of 1984. The outlet is shown below.
B-5 This subarea contains 7.9 acres. It is served by
an 18" AC outlet pipe. The pipe is fed by two
inlets, one on each side of Maple Avenue, and
drops to the ocean at Maple Avenue. The pipe was
repaired and erosion refilled recently, as can be
seen in the picture below.
-11-
i
•
•
i
JT ORIGINAL
i
1
i
i
B-6 This subarea contains 5.8 acres. It is served
by an 18" PVC pipe with O-ring joints. The pipe
is fed by four inlets along the east side of
Carlsbad Boulevard. The outlet pipe was repaired
and erosion refilled during the winter of 1984.
This pipe drops to the ocean just south of Acacia
Avenue.
B-7 This subarea contains 5.0 acres. It is served by
a 12" CMP outlet pipe. The pipe is fed by a
single inlet along Juniper Street and drops to
the ocean at Juniper Street. The outlet pipe is
exposed, as can be seen in the pictures below.
-12-
L - •-»"• • ^. «P>-
B-8 This subarea contains 12.8 acres. Storm waters
flow overland and follow the east side of Carlsbad
Boulevard to Agua Hedionda.
B-9 This subarea contains approximately one acre. It
is composed of a small strip of land along the
west side of Carlsbad Boulevard. There are seven
storm drains which serve this area. Although the
contributing drainage area to each drain is
small, there is still considerable erosion from
these drains. Also, there appear to be some low
spots in the Carlsbad Boulevard curb which allow
water to escape over the side of the street and
down the bluffs. The location, as well as a
description of each drain, is listed below the
following pictures of the drains.
-13-
B-9a Pine Avenue 10" CMP
.,
a
>T ORiGiSMAL
B-9b 150' south of Pine Avenue 8" CMP
-14-
B-9c 50' south of Sycamore 10" CMP
B-9d 100' north of Maple 10" CMP
B-9e 50' south of Maple 3 pipes only 1 is active
-16-
^^^fe^^SB^^_^ ••'Sp^^iVvv,,:_.. ^
'^-•^f. -;>--"W!L*> *&'± '^. v??«-ct-. . --s^;^ v:7^__T*; •'a- *^s.::ji iX-f^ic.sA.
B-9f 50' north of Juniper 6" CMP
lp^;^vx,Aji^lpM!i»
•-. *Jar-£V-; i» I T> t^.;, y^5;.fe*ift.,V^'^di'^^k\V^*Ay^*,^AW;!,:hi^Y<W:;,Sl^^/1;:%
8-99 100' south of Hemlock Q" PVC
— 1 7 —
Area C
Area C extends from the power plant outlet at the south end
of Agua Hedionda to Cerezo Drain. This area contains very few
storm drains and much of the area is similar to Area A. A large
portion of Area C has been developed with single family homes
constructed on the bluff and most of the streets in this area
have curbs and gutters. The undeveloped sections of this area
to the north need some improvements to prevent water from
running off Carlsbad Boulevard and over the bluffs. However,
there does not appear to be a major erosion problem in this
area. The drainage basin east of Carlsbad Boulevard which flows
overland needs improvements, but the storm water flows into Aqua
Hedionda and not onto the beach so there is not a bluff erosion
problem.
This area contains approximately 28 acres and 5 subareas.
C-l This subarea contains 2.1 acres. It is served
by a 15" CMP and an 8" CMP outlet pipe. Storm
water collects along the west side of Carlsbad
Boulevard and flows northward. These pipes
appear to have been installed with highway
improvements. The outlet pipes are approximately
300' south of the power plant cooling water
outlet bridge. The two outlets are pictured
below.
ms^m?s*mm^$&ls$%->?& w*
C-la 8" CMP
_T Q _
XC5
i
•'• --•••^--.•«J,.-
- ^ "
C-lb 15" CMP
C-2 This subarea contains 14.9 acres. Storm water
collects along the east side of Carlsbad
Boulevard and flows overland to Agua Hedionda.
C-3 This subarea contains 3.8 acres. It is served
by an 18" RCP outlet pipe which was installed
during the winter of 1984. The area it serves
is fully developed with single family dwellings.
The outlet pipe is 100" north of the southern
end of Tierra del Oro Street.
C-4 This subarea contains 3.8 acres, and is served
by a broad concrete lined surface ditch. The
ditch also serves as a walkway to the beach. The
ditch was installed with subdivision improve-
ments. The concrete surface ditch seems to
serve both funtions well and the system could
solve problems in other areas of the city. The
area it serves is fully developed with single
family dwellings. The ditch is near the north
end of Shore Drive. The ditch is shown below.
-19-
I
I
I
I
I
1
1
I
1
1
1 C-5 This subarea contains 3.0 acres and is now fully
developed with single family dwellings. The
outlet pipe is near the southern end of Shore
Drive.
Area D
Area D extends from Cerezo Drive south to the Encinas Creek
Bridge. All land adjacent to the ocean in this area is part of
the State Park System. The state land has not been improved
for use as a park. Beach access is difficult and, in some
areas, impossible. The storm drains in this area are all old
and appear to date from the same time period. Thus, there are
no abandoned drains as were prominent in area B. The storm
drains in this area appear to be reaching the end of their
useful life and substantial bluff erosion could occur in this
area in the immediate future if improvements are not installed.
-20-
At the north end of this area the storm drain system is
near failure. The system as it was installed conveys water
across Carlsbad Boulevard and empties it on the top of the
bluff. The water flows overland across the top of the bluff
and enters three storm drains which carry it over the edge of
the bluff. The Bluffs in this area are quite wide and the
storm water appears to spread out over the bluff and not follow
clearly defined paths to the three drains which convey it over
the bluff.
The three drains which convey water over the bluff resemble
a dam spillway and carry water over the edge, but do not allow
the water to erode the top of the bluff. However, wave action
has eroded the bluff and the three storm drains will soon fall
into the ocean. When this occurs, storm water will go over the
top of the bluff, and without the pipe protecting the bluff,
rapid erosion of the bluff will occur. Surprisingly, this area
has not experienced much storm erosion and the overland flow
system has worked. The southern end of this area has a few
storm drains and they all need some repair. Storm water erosion
has left some wide gullies in this area.
This area contains approximately 30 acres and 9 subareas.
Most of the drains in this area appear to have been installed
with the highway improvements.
D-l This subarea contains 12.9 acres. It is served
by an 18" RCP which conveys storm water from the
east side of Carlsbad Boulevard to the west side
of Carlsbad Boulevard. This pipe appears to have
been installed when Carlsbad Boulevard was con-
structed. The subarea is almost fully developed
with single family dwellings. The drain from this
subarea empties onto subarea D-2 between Cerezo
Drive and Manzano Drive.
D-2 This subarea contains 7.4 acres. It is served by
three 15" CMP outlets. The State Park System
owns this undeveloped area. Storm water from
both D-l and D-2 collects in area D-2 and flows
overland to the three outlets. The outlets
function as spillways. All three outlets are
close to failure because wave erosion has eroded
the bluff nearly to the inlet. When these
outlets fail, severe bluff erosion will occur.
Repairs are urgently needed. One outlet pipe is
100" south and one is 250' south of Cerezo Drive.
The last outlet pipe is 100' south of Manzano
Drive. Two of the outlets are shown below.
-21-
-22-
D-3 This subarea contains 1.3 acres. The outlet pipe
for this subarea is not evident from the beach.
However, there is an eroded channel in the bluff
providing evidence that the outlet is properly
hidden under the iceplant on the bluff. This is
one of the many small subareas formed by the
intersection of Carlsbad Boulevard and Palomar
Airport Road. The outlet pipe is 450' south of
Manzano Drive.
D-4 This subarea contains .7 acres. It is served by
a 12" CMP outlet pipe. The pipe is fed by two
inlets along Carlsbad Boulevard. This subarea is
also formed by the Carlsbad Boulevard/Palomar
Airport Road intersection. The outlet pipe is
near the circular parking area on the southbound
lanes of Carlsbad Boulevard. The outlet pipe is
shown below.
-23-
D-5 This subarea contains 4.3 acres. It is served by
an 18" CMP outlet pipe. The pipe is fed by four
inlets along Carlsbad Boulevard. This is the
last of the subareas formed by the intersection
of Carlsbad Boulevard and Palomar Airport Road.
The outlet has caused severe erosion because the
pipe is broken under the old roadbed. The outlet
pipe is just south of the intersection of
southbound Carlsbad Boulevard with the on ramp
from Palomar Airport Road. The outlet is shown
below.
D-6 This subarea contains 1.3 acres, and is served by
an 18" CMP outlet pipe. The pipe is fed by two
inlets. The outlet has caused severe erosion
because the pipe is broken approximately 5" from
the old roadbed. The outlet pipe is.approximately
850' north of the Encinas Creek Bridge. The
outlet is shown below.
-24-
D-7 This subarea contains .9 acres. It is served by
an 18" CMP outlet pipe. The pipe is fed by a
single inlet on the east side of the southbound
lanes of Carlsbad Boulevard. The outlet pipe is
approximately 600' north of the Encinas Creek
Bridge. The end of the outlet pipe is covered
with ice plant and is difficult to locate.
D-8 This subarea contains 1.3 acres. It is served by
an 18" CMP outlet pipe. The pipe is fed by a
single inlet on the east side of the southbound
lanes of Carlsbad Boulevard. The outlet pipe is
approximately 350' north of the Encinas Creek
Bridge. The outlet is shown below.
-25-
D-9 This subarea contains .5 acres. It is a minor
subarea on the west side of the southbound lane
of Carlsbad Boulevard. There are no storm drain
improvements in this area and storm water flows
overland.
Area E
All land in Area E adjacent to the ocean is part of the
State Park System. Area E extends from Encinas Creek on the
north to Batiquitos Lagoon on the south. This area is entirely
developed as a campground. The bluff in this area is quite
high and all access to the beach from the campground is by
stairs. There are several storm drains greater than 18" in
this area and also many drains smaller than 18". A storm drain
smaller than 18" is not effective. There has been substantial
erosion from some of the smaller storm drains, but the larger
drains have caused little erosion.
This area has little need for emergency repairs, but the
area should have major improvements to prevent erosion in the
future.
nr
-26-
This area has approximately 140.8 acres and is split into
10 subareas.
E-l This subarea contains .9 acres. It is served by
an 18" CMP outlet pipe. The pipe is currently fed
by one inlet on the west side of the southbound
lanes of Carlsbad Boulevard. One pipe which
continues east from this inlet, but apears to be
abandoned and not in service at this time. The
outlet is broken off under the old roadbed for
Carlsbad Boulevard. The broken pipe has eroded
under a portion of the old roadbed and caused it
to collapse. The outlet pipe is 300' north of
the northern end of the parking lot. The outlet
is shown below.
-27-
E-2 This subarea contains 2.6 acres. The original
pipe was replaced with an 8" PVC pipe with 0-ring
joints during the winter of 1984. The erosion
caused by the failure of the old pipe was also
filled when the old pipe was replaced. The 8"
pipe is fed by a single inlet. This subarea is
composed entirely of state park campground. The
outlet pipe is 150' south of the northern end of
the campground (Campspace 70) . The repairs are
shown below.
-28-
E-3 This subarea contains 1.7 acres. The original
pipe was replaced with an 8" PVC pipe with 0-ring
joints during the winter of 1984. The erosion
caused by the failure of the old pipe was also
filled when the old pipe was replaced. The 8"
pipe is fed by a single inlet. The subarea is
composed entirely of state park campground. The
outlet pipe is 550' south of the northern end of
the campground (Campspace 57) . The repairs are
shown below.
JT
-29-
E-4 This subarea contains 14.9 acres. It is served
by a 24" CMP outlet pipe. The pipe is fed by four
inlets. The subarea is composed of state park
campground land, a long section of Carlsbad
Boulevard, and an area of vacant land on the east
side of Carlsbad Boulevard. There is evidence of
erosion along the pipe, but it is not as severe
as the erosion along some of the smaller storm
drain pipes in this area which carry far less
flow. The outlet pipe is near the middle of the
mobile home park on the east side of Carlsbad
Boulevard (Campspace 45) . The outlet is shown
below.
>T ) fi if*t. 0 !
-30-
E-5 This subarea contains 2.7 acres. It is served by
an 8" CMP outlet pipe. The pipe is fed by two
inlets. The subarea is composed of state park
campground and a small section of Carlsbad
Boulevard. The outlet pipe has collapsed and
lower portions of the pipe have broken away.
This pipe is in need of immediate repair. The
outlet pipe is 800' north of the campground
entrance (Campsite 32) . The outlet pipe is shown
below.
™i! 31 I
-31-
E-6 This subarea contains 3.5 acres, and is served by
an 8" CMP outlet pipe. The subarea is composed
of state park campground and a small section of
Carlsbad Boulevard. The outlet pipe appears to
have been repaired in the past. The current pipe
is exposed and bridging long spans. The outlet
pipe is approximately 350' north of the campground
entrance (Campsite 12). The outlet pipe is shown
below.
-32-
E-7 This subarea contains 4.3 acres. The original
pipe was replaced with an 8" PVC pipe with 0-ring
joints during the winter of 1984. The erosion
caused by the failure of the old pipe was also
filled when the old pipe was replaced. The 8"
pipe is fed by a single inlet. The subarea is
composed entirely of state park campground. The
outlet pipe is approximately 200' south of the
campground entrance (at Campfire Center). The
repairs are shown below.
^-^^^t^^
-33-
E-8 This subarea contains 37.9 acres. It is served
by a 24" outlet pipe. This subarea is composed
of state park campground, a large section of
Carlsbad Boulevard, and a very large section of
undeveloped land east of Carlsbad Boulevard. The
outlet pipe was recently replaced and fill placed
around it. The outlet pipe is 700" south of the
campground entrance (Campspace 205) . The outlet
is shown below.
IT ORIGINAL
-34-
E-9 This subarea contains 1.7 acres. It is no longer
served by a pipe. The original pipe failed and
caused a great deal of erosion. The erosion has
not been repaired, but some unsightly attempts to
prevent erosion are evident as seen in the picture
below. The storm water now flows overland down a
beach access road, approximately 1300' south of
the campground entrance and 350" north of the
Ponto undercrossing (Campspace 183).
•<•• •^..'•.•.-•:-*~-- -v- • ••..jy-'v". ->'• '•^fyesj^f- • -<*W«^' - ' '-^-iiv'fiv.'-: y^-.
-35-
E-10 This subarea contains 69.5 acres. It is served
by a 30" CMP outlet pipe. This is the largest
subarea in the study. It is also the only subarea
to serve land east of the railroad tracks. This
subarea is composed of state park campground, a
portion of Carlsbad Boulevard, the developed
Ponto area, undeveloped land north and south of
Ponto, and a large portion of the trailer park
east of the railroad tracks. The outlet pipe for
this subarea is undersized. However, there is no
erosion along the outlet pipe. The lack of
erosion is probably attributable to the deep grade
and slight slope of the pipe through the bluff
area.
The outlet pipe is just south of the Ponto under-
crossing (Campspace 168). The outlet is shown
below.
•••Js,.--i,•'-'-v • - •.-;.»,.-'.M
•«'>*^i%^^*&'Q**"•" •'•-•• "\, _•• ;V r^^.'^
v.y A
-36-
E-ll This subarea contains 1.1 acres, and is no longer
served by a pipe. The original pipe failed and
has not been replaced. The storm water flows
along the campground road to the corner of the
maintenance yard and over the bluff.
IT ORIGINAL
-37-
Chapter 3
Bluff Erosion
In surveying the storm drains along the coast, it was
possible to see virtually all stages involved in the failure of
a storm drain. In the Carlsbad coastal area the failure of a
storm drain causes immediate erosion. Two major erosion forces,
waves and storm water, plague the coast. The results of each
type of erosion are easy to distinguish.
When wave action erodes the bluff, the erosion is parallel
to the coast. The waves undercut the bluffs and large sections
fall into the ocean. This type of erosion creates high, steep
bluffs parallel to the coast line. This type of erosion
proceeds more rapidly when sand is absent from the beach. Since
the Carlsbad beaches have less sand each year, the wave erosion
problem is increased every year. Thus, as the amount of sand
has diminished, the bluff erosions due to wave action has
increased.
In contrast, storm water erosion of the bluffs occurs
perpendicular to the coast. Water running over the bluffs
rapidly erodes wide gullies and these gullies broaden and deepen
as they near the beach. On a natural bluff very little water
flows directly over the bluff. Storm water would be directed
parallel to the coast and enter the beach area through major
drainage courses. As development has occurred storm drains
have been installed to collect storm water and these drains
have generally taken the shortest path to the beach, which is
directly over the bluffs. These storm drains have periodically
failed, substantially increasing bluff erosion.
Most of the storm drains along the beach can be described
as follows: The slope of the drains is generally slight as the
drain approaches the bluff. At the bluff a sharp bend is
installed, with a very steep section of pipe down the bluff.
An outlet structure is then installed on the end of the pipe at
the bottom of the bluff.
There are a number of reasons why a storm drain may fail,
but the following summarizes the general steps in the failure
of a storm drain.
1. The outlet of the storm drain is plugged, moved,
or both, by wave action causing the joints to
leak.
2. Storm water escapes from the leaky joints and
rapidly erodes the steep fill around the pipe.
3. The erosion undermines the pipe, eventually
causing the pipe to collapse.
-38-
1
I
I
i
!
1
i
1
I
!
i
4. Storm water from the collapsed pipe erodes a wide,
deep gully where the storm drain used to be.
There are a number of preventative measures which can reduce
storm drain failures and the associated erosion. The long-term
solution is to create a master system of coastal drains which
collect all of the existing local drains and convey the water
parallel to the coast and into major drainage channels. A long
term plan is developed, and estimated costs provided, for this
type of system in Chapter 5.
If the master system is not installed there are a number of
measures that can be taken to reduce the failure rate of the
existing storm drains. These preventative measures are listed
below.
1. Existing outlets can be protected from wave
action. This can be accomplished by a number of
mechanisms, but care must be exercised to
construct an outlet which will not be easily
blocked. Replacement of lost beach sand is one
method of protecting outlets. Another method is
to locate outlets higher up the slope away from
wave action. However, if the outlet is above the
beach level a concrete structure or rip-rap will
need to be placed at the outlet to prevent scour
and erosion at the outlet.
2. Since an integral step in the failure of a storm
drain involves the joints, install storm drain
piping with water tight joints. Most of the storm
drains installed in the past were corrugated
metal. Corrugated metal pipe does not have water
tight joints.. PVC piping with water tight 0-ring
joints would greatly reduce joint leakage. 0-ring
joints would most likely remain watertight despite
slight movement of the outlet structure. Thus,
0-ring joints would reduce joint leakage and thus
bluff erosion. However, if PVC pipe is installed
periodic inspections will be needed to check for
exposed pipe sections. PVC decomposes when
exposed to sunlight.
3. Storm drain piping grade should be reduced and its
depth increased. One of the major contributing
factors to the storm drain bluff erosion is the
steep grade of the drains. Water flowing down a
steep slope will carry more material with it than
water flowing down a slight slope. Thus, if the
drains were installed with a level invert through
the bluff area and the steep slope was moved away
from the beach, the erosion potential would be
reduced. There is one large corrugated metal
-39-
drain installed in this manner and it appears to
have functioned without causing bluff erosion for
a number of years, while other storm drains which
appear to have been installed at the same time
have failed.
4. Inlets should be located to prevent water from
going over the bluff when storm drain inlets are
plugged. When new inlets are installed or old
ones replaced or relocated they should be placed
to prevent water from going over the bluff when
inlets are plugged. Some of the existing inlets
are placed such that when they plug the water
goes directly over the bluff with little ponding.
These should be relocated such that major ponding
occurs so that maintenance crews can be alerted
to the ponding and clear the drain. If ponding
does not occur the drain may remain clogged for a
long period of time, since no one would alert the
city that it was plugged.
5. Storm drain systems should be analyzed to
determine what will occur should the outlet
become plugged. All storm drain piping systems
should be designed to withstand the hydrostatic
pressure when an outlet is plugged. A failure
analysis should be conducted to see what will
occur when outlets are plugged. When the outlet
is plugged the storm water should pond to alert
maintenance crews that there is a problem. If
the joints will not hold the hydrostatic pressure
the storm water will escape through the joints
when the outlet is plugged and cause bluff
erosion. The inlets should be located such that
storm water will pond and not escape over the
bluff.
6. In areas where it is impossible to relocate inlets
to allow ponding and storm drain blockage will
lead to water going over the bluff, surface drains
should be considered. Surface drains would also
provide pathways to the beach and help to mitigate
erosion caused by beach users.
7. Storm drains should have a minimum size of 18".
Many of the storm drain failures, especially in
the state park campground, have occurred in the
undersized drains. Virtually all of the 8" drains
in the campground have failed. Also, the erosion
caused by the failure of small drains is as severe
as that caused by larger drains.
-40-
Chapter 4
Needed Repairs
Chapter 5 provides an estimate of the costs to construct a
master storm drainage system which would eliminate nearly all
of the present outlet pipes to the ocean. If the master storm
drainage system is constructed, many of the repairs listed in
this chapter may not be needed and those which are needed may
be less costly if temporary repairs are made.
If the master drainage system proposed in Chapter 5 is not
adopted, then all listed repairs should be made. The repairs
should be done in accordance with the recommendations in
Chapter 3.
There are a number of storm drains identified in this study
needing repair. This study splits the drains into two cate-
gories. The first category contains drains urgently needing
repairs, where erosion will soon undercut roadways or improved
parking lots. Also included in this category are drains which
will soon fail and have the potential for substantial natural
bluff erosion.
The second category consist of drains needing repairs to
restore the drains to original condition and prevent further
erosion, but the repairs are not as urgent as the repairs noted
in the first category. Included in the second category are
drains which have undercut the old Highway 101 roadbed in areas
where it is used as an unimproved parking lot.
The repairs have also been divided into two groups by land
ownership. All drains which begin and end on state park land
are list^separately.
Urgent Repairs: City of Carlsbad Drains
B-l The northern drain in this drainage basin is
beginning to undercut the parking lot. If repairs
are not made, areas of the lot may collapse. The
CMP pipe should be replaced with PVC pipe and the
erosion refilled. The estimated cost for repairs
is $15,000.
B-2 The pipe which serves this area has eroded the
bluff and will soon begin to undercut the parking
lot on the end of Ocean Street. The large growth
of bamboo is slowing erosion, but this drain
should be repaired and the erosion filled. The
estimated cost for these repairs is $10,000.
-41-
Urgent Repairs; State Park Drains
I- D-2 The three drains which serve this area should be
'- reconstructed. The drains will soon collapse,
leaving the bluff unprotected. Storm water will
1 cause rapid erosion on the unprotected slopes.
The estimated cost for these repairs is $50,000.
I
1
E-5 The pipe which serves this area has failed and
will rapidly erode the bluff. The drain should
be replaced and the slope refilled. The estimated
cost for repair is $37,500.
Other Needed Repairs
1 There are a large number of drains which need to be
repaired. Most of the drains need to be refilled and new pipe
installed. Table 4-1 lists the drains and needed repairs. The
table lists City of Carlsbad Drains separately from State ParkIarea Drains. Most of the money needed to fix these drains
could be better spent on the needed master facilities. The cost
presented are to restore the drains to their original condition.
I The drains should be expected to fail again, since the original
installation has failed.
I
I
I
I
I
I
I
I
I
I
Many of the drains in the state park campground are under-
sized and should be replaced. However, the need for each of
these repairs should be judged independently, remembering that
the master facilities recommended in the next chapter would
eliminate the need for these repairs.
-42-
TABLE 4-1
NEEDED REPAIRS TO EXISTING DRAINS
CITY OF CARLSBAD DRAINS
Drain
D-5
!
,
E-l
B~9g
I D-6
E-4
I B-7
. B-9a
B-9b1- •
B-9c
B-9d
D-3
' D-4
• D-7
I D-8
B-9f1
B-5
1 B-9e
Description of Repairs
Replace pipe, refill and rock outlet
Replace pipe, refill and rock outlet
Refill pipe, rock outlet
Replace pipe, refill and rock outlet
Refill pipe, rock outlet
Replace pipe with 18", refill and rock around outlet
Refill pipe, rock outlet
Refill pipe, rock outlet
Replace < pipe , refill and rock outlet
Refill pipe, rock outlet
Locate pipe and repair
Replace pipe, refill and rock outlet
Replace pipe, refill and rock outlet
Replace pipe, refill and rock outlet
Refill and rock around outlet
Refill both pipes
Refill and rock around outlet
Refill and rock around outlet
Cost
$ 37,500
37,500
15,000
37,500
22,500
37,500
15,000
15,000
37,500
15,000
37,500
37,500
22,500
15,000
12,000
7,500
7,500
7,500
Subtotal $417,000
-43-
I
TABLE 4-1
NEEDED REPAIRS TO EXISTING DRAINS a (continued)
STATE PARK DRAINS
•1 Drain
E-6
• E"9
4 E-ll
E-2b
1 E-3bE-7b
Description of Repairs
Replace pipe with 18", refill and rock outlet
Remove debris, refill, improve road drain
Remove debris, refill, improve road drain
Replace pipe with 18", refill and rock outlet
Replace pipe with 18", refill and rock outlet
Replace pipe with 18", refill and rock outlet
Cost
$ 37,500
30,000
22,500
37,500
37,500
37,500iSubtotal
TOTAL
$202,500
$619,500
1
1
1
I
1
1
1
Drains are listed with those needing repairs the
most first.
These drains have recently been repaired. They
are listed as needing repairs because the new
pipe is 8" and the minimum storm drain size should
be 18".
-44-
1
I
I
I
I
I
1
I
1
1
1
I
1
Chapter 5
Master Facilities
Figures 5-1 through 5-4 show the Master Facilities needed
to collect storm water and convey it parallel to the coast and
reduce the bluff erosion caused by storm water. Each area will
be discussed below and improvements recommended. Table 5-1
summarizes the recommended improvements. A description of each
pipe reach as well as cost information may be found to this
table.
Area A
The existing drains in this area are adequate and no new
facilities are planned for this area. The area is fully
developed and, the existing drains, upon failure, would cause
more damage to improvements in the area than to the bluff. The
only improvements needed to this area are curb and gutter to
eliminate the nuisance puddles.
Area B - Whale Watch Area
A storm drain should be constructed in Carlsbad Boulevard,
beginning at Pine Avenue and continue south to Agua Hedionda.
The drain will vary in size from 24" to 48". The approximate
length of the needed improvements is 4,290". The estimated
cost for these improvements is $572,000. Table 5-1 summarizes
the needed improvements.
We looked at the alternative of installing two pipelines to
serve this area. One would start at Sycamore and flow north,
the other would start at Maple and flow south. This alternative
was slightly more expensive, but it should be reevaluated during
final design if master facilities are constructed in this area.
The proposed facilities are quite deep and the alternate of two
drains eliminates some of the deep sections of storm drain.
The westerly curb of Carlsbad Boulevard should also be
raised to prevent storm water from going over the curb. Also,
drainage patterns in the Whale Watch area should be reviewed to
make sure the storm water does not go over the bluff. It
appears that curb breaks for handicapped persons may have
re-routed some of the storm water flows.
Area C - Terra Mar Area
A storm drain is needed as the majority of the storm water
will come from the developed area east of Carlsbad Boulevard.
The drain should begin in Area D just south of Cerezo Drive and
continue north to Agua Hedionda. The developed area west of
Carlsbad Boulevard would not be served by this new storm drain.
This area would continue to be served by the existing drains.
-45-
TABLE 5-1
«Contributory
Subareas
H Whale Watch Area
~ (Flows South)
m B-I
B-l - B-2
•j B-l thru B-3
I B-1 thru B-4*
l| -B-l thru B-5
•
•^ B-l thru B-6
~ B-l thru B-7
B-l thru B-9
1
Location & Description
of Improvements
Ocean St. North of Pine Ave.
230' of 24"
Carlsbad Blvd., Pine Ave. to
Walnut Ave.
540' of 30"
Carlsbad Blvd., Walnut Ave.
to Sycamore Ave.
220' of 36"
Carlsbad Blvd., Sycamore Ave.
to Maple Ave.
630' of 36"
Carlsbad Blvd. , Maple Ave.
to 140' So. of Acacia Ave.
470' of 42"
Carlsbad Blvd., 140' So. of
Acacia Ave. to Juniper Ave.
550' of 48"
Carlsbad Blvd., Juniper Ave.
to Tamarack Ave.
850' of 48"
Carlsbad Blvd. , Tamarack Ave.
to Agua Hedionda Lagoon
800' of 48"
Total Acres
Served
6.0
10.7
14.0
17.4
25.3
31.1
36.1
49.9
Approximate
Flow Line
Depth (feet)
8
13
17
19
21
24
22
10
Costs
(Thousands
of Dollars) a
15
46
23
66
71
94 .
145
112
I Subtotal 572
-46-
TABLE 5-1
SUMMARY OF COST FOR MASTER DRAINAGE SYSTEM (continued)
1^,-V, -.,..-,. ; .-; ,— — —
!
Contributory
Subareas
I
I
[
i
Terra Mar Area
(Flows North)
D-l, D-2
D-l, D-2
and C-2
D-l, D-2
C-2 & C-l
9
Location & Description
of Improvements
Carlsbad Blvd., 470' So. of
Cerezo Dr. to Cannon Road
2,150' of 42"
Carlsbad Blvd., Cannon Rd.
to 650' No. of Power Plant
Outlet
1,800' of 48"
Carlsbad Blvd., 650' No. of
Power Plant Outlet to Agua
Hedionda Lagoon
350"1 of 48"
Total Acres
Served
20.3
35.2
37.3
Approximate
Flow Line
Depth (feet)
9
9
5
Costs
(Thousands
of Dollars) a
226
225
44
Subtotal 495
Palomar Airport
Rd. to Encinas
Creek (Flows
South)
D-3
D-3 & D-4
D-3 thru D-5
Southbound Carlsbad Blvd.
900' South of Manzano Dr.
to just North of paved
loop adjacent to South-
bound lanes of Carlsbad
Blvd.
350' of 18"
Southbound Ca'rlsbad Blvd.
just North of paved loop
to end of Palomar Airport
Road onramp.
500' of 18"
Southbound Carlsbad Blvd.
end of Palomar Airport Rd.
onramp to 800' South of
onramp.
800' of 24"
1.3
2.0
6.3
11
13
19
30
52
-47-
I
TABLE 5-1
|- SUMMARY OF COST FOR MASTER DRAINAGE SYSTEM (continued)
_ Contributory
Subareas
_
Palomar Airport8Rd. to Encinas
_ Creek (Flows
South) (con 't)
I D-3 thru D-6
.
1
m* D-3 thru D-7
1 •^3 *
*
1
\ D-3 thru D-9
Location & Description
of Improvements
Southbound Carlsbad Blvd.
800' South of onramp to
1,160' North of Encinas
Creek Bridge
430' of 27"
Southbound Carlsbad Blvd.
1,160' North of Encinas
Creek Bridge to 650'
North of Bridge.
510' of 27"
Southbound Carlsbad Blvd.
650' North of Encinas
Creek Bridge to Bridge.
650' of 27"
Total Acres
Served
7.6
8.5
10.3
Approximate
Flow Line
Depth (feet)
12
7
5
Subtotal
Northern Part
of State Park
• Campground
™ (Flows North)
<E-5
.
Southbound Carlsbad Blvd.
Campspace 32 to
Campspace 45 .
800' of 18"
2.7
Costs
(Thousands
of Dollars) a
30
33
42
206
I
8 44
•
1 '
1
-48-
I
1
I
TABLE 5-1
SUMMARY OF COST FOR MASTER DRAINAGE SYSTEM (continued)
•f
1
(Contributory
_. Subareas
1 Northern Part
of State Park
_ Campground
1 (Flows North)
E-4, E-5
-
I E-3 thru E-5.
~ , . E-2 thru E-5
1*L •
E-l thru E-6
i
I Sut
| Southern Part
- of State Park
Campground
1 (Flows South)
E-6
!
Location & Description
of Improvements
Southbound Carlsbad Blvd.
Campspace 45 to
Campspace 57
650' of 36"
Southbound Carlsbad Blvd.
Campspace 57 to
Campspace 70
720' of 42"
Southbound Carlsbad Blvd.
Campspace 70 to 1,100 feet
North of Encinas Creek
Bridge
600' of 42"
Southbound Carlsbad Blvd.
1,100 feet North of Encinas
Creek Bridge to 400 feet
North of Bridge
700 ' of 42"
3total
Southbound Carlsbad Blvd.
Campspace 12 to the
Campfire Center
1,000' of 18"
Total Acres
Served
17.6
19.3
21.9
22.8
3.5
Approximate
Flow Line
Depth (feet)
14
19
13
5
Costs
(Thousands
of Dollars) a
62
97
72
74
349
5 55
-49-
TABLE 5-1
SUMMARY OF COST FOR MASTER DRAINAGE SYSTEM (continued)
Contributory
- Subareas
Southern Part
of State Park
Campground
_ (Flows South)
E-6, E-7
"
E-6 thru E-8
1
t .
".." E-6 thru E-9
~
-
L E-6 thru E-10
-
E-6 thru E-ll
.
Location & Description
of Improvements
Southbound Carlsbad Blvd.
Campfire center to
Campspace 205
950' of 27"
Southbound Carlsbad Blvd.
Campspace 205 to
Campspace 183
1,150' of 54"
Southbound Carlsbad Blvd.
Campspace 183 to
Campspace 168
750' of 54"
Southbound Carlsbad Blvd.
Campspace 168 to
Southern end of .Campground
maintenance yard
900' of 72"
Southbound Carlsbad Blvd.
Southern end of Campground
maintenance yard to Batiqui
tos Lagoon Bridge
1,200' of 72"
otal Acres
Served
7.8
45.7
47.4
116.9
Approximate
Flow Line
Depth (feet)
8
15
19
16
iI
118.0 9
Costs
(Thousands
of Dollars)
62
207
135
216
240
Subtotal
TOTAL
915
2,537
Costs include engineering
-"0
-50-
The new drain will vary in size from 42" to 48". The
approximate length of the needed improvements is 4,300' and the
estimated cost is $495,000. Table 5-1 summarizes the needed
improvements.
Area D - Palomar Airport Road to Encinas Creek
The drainage basins in this area are defined by the roads.
Since the roads in this area may be changed as the area is
developed as a state park, future drainage improvements should
be integrated with the state park improvements.
The future drain will have to begin near the Palomar
Airport Road - Carlsbad Boulevard intersection. The drain will
then continue south to the Encinas Creek Bridge. The new drain
will vary in size from 18" to 27". The approximate length of
the needed improvements is 3,240' and the estimated cost is
$206,000. Table 5-1 summarizes the needed improvements.
Area E - State Park Campground
There are two future drains which are needed to serve this
area. Both drains begin between the trailer park and the
developed Ponto Area. One of the drains flows north to the
Encinas Creek Bridge and the other flows south to Batiquitos
Lagoon.
The northern drain varies in size from 18" to 42". The
approximate length of the needed improvements is 3,470' and "the
estimated cost is $349,000.
The southern drain varies in size from 18" to 72". The
approximate length of the needed improvements is 5,950' and the
estimated cost is $915,000.
Table 5-1 summarizes the needed improvements for both
drains.
-51-
I
l?f:
CONTINUATION SEE BELOW
'hfCv^v^) 1800' OF 48" —
FOR CONTINUATION SEE FIGURE 5 -2-
220' OF 36
•540' OF 30"
230' OF 24"
WHALE WATCH AREA
FLOW —^
(SOUTH)
".BOULEVARD
FOR CONTINUATION SEE ABOVE
470' OF 42"
TERRA MAR AREA
FLOW-*-
(NORTH)
MASTER STORMDRAlN FACILITIES
WILSON ENGINEERING
FIGURE 5-1
2150' OF 42"
-FOR CONTINUATION SEE FIGURE 5
TERRA MAR AREA
PALOMAR AIRPORT ROAD TO ENCINAS CREEK AREA
FLOW ~*~
(SOUTH)1
(NORTH)
600' OF 42"-
FQR CONTINUATION SEE FIGURE 5-3
NORTHERN PART OF
STATE PARK CAMPGROUND AREA
FLOW-**—
(NORTH)
MASTER STORMDRAilN FACILITIES
WILSON ENGINEERING
FIGURE 5-2
• • :S%W/
i.m=Mv- •
950' OF 27" \ 750' OF 54"
I 150' OF 54"
FOR CONTINUATION SEE FIGURE 5-2 FOR CONTINUATION S£E FIGURE 5-4
NORTHERN PART OF
STATE PARK CAMPGROUND AREA
(NORTH)
SOUTHERN PART OF
STATE PARK CAMPGROUND AREA
FLOW —B»-
(SOUTH)
MASTER STORMDRAIN FACILITIES
WILSON ENGINEERING
FIGURE 5-3
;. -• v
7 T\-
1200' OF 72"
-FOR CONTINUATION SEE FIGURE 5-3
SOUTHERN PART OF
STATE PARK CAMPGROUND AREA
FLOW
(SOUTH)
MASTER STORMDRA1N FACILITIES
WILSON ENGINEERING
FIGURE 5-4