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HomeMy WebLinkAbout3205; CARLSBAD BLVD WIDENING PHASE 3; COSTAL STORM DRAIN STUDY; 1984-04-01rp - 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 o ................. 41 p 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 -: Page ES-i Coastal Storm Drain .. . Areas . . . . - 2 5-1 through 5-4. Master Drainage Facilities... . . At Back of Report - - - . -- -V 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 beachfrorit 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. 'AreaB 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. Area C Area' C, known as the Terra Mar area, extends' from the power, plant outlet at the south end of Agua Hediond,a 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 ',.1 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 Cerez'o 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 b,een 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 shbuld''be installed in this area when it is developed as a park. Eliminating the present system and replacing it with a single drain par ,aliel 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 '• '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 carnpground 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. ' ,0 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, Li •. ,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- \\'J"1I\I\ COASTAL STORMDRAN \. AREAS 1'.kcNk'. \ .• Area C, 0 0• • \ /\\-A> • Area B 0 lea 0•••• 00 D?q • • * • • ' __•_c • . \ • 0 Area C A re a D I / ...................... \ k ?0' \ 4) I \ \ • . . \. \\\\\\. i.1'\ •\(8 . • Area E \I\' 0 • 0 • . \ \. \•. \ S • . S •, \ \ \\.y \. • . S • BA !Q 33 S • • S • • •0 • \\\\ ••\\ I .lt1 \\\. I WILSON ENGINEERING • - • - :/i•± RGURE •-ES - I • • • S S. • • • \•' 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 existing drains, an identification of 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 I p - • • • • • • • • •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 sub ,area. 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 M ' 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 and these 4 subareas are described below. ' A-i This, subarea contains 2.7 acres. 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. -- 9 TABLE 2-1 - - SUMMARY OF SUBAREAS Flow Generated Outlet Outlet Undersized a Area/Subarea Acres .(CFS) Pipe Size .` Cpacity Pipe S ' 2.5,CFS/Ac,re and Type . . (CFS) . Capacity/<18" A 1 - 2.7 .6.8 18" PVC* 2 : '- 9.9 - 24:8 18" AC . 25.5 3 95 238 18". AC 265 4 5 2.9, 7.3 . 12" avip . 7:9 .25.0 Totals 1 ., 6.0 15.0 . Varies - . 2. - - 47 -. - 11.8 - Unknown .. . - . .. 3 55 33 - ,..8.3 - 18". PVC : .26:5 . . .. - - .4 3.4 8:5 . •. - 18'• PVC 26.5 ,. . . - -• , r 5 79 198 18" AC 265 6 5.8 -,14.5. 18" PVC 26.5 - .7 - . 5.0 - 12:5 12T CVI . 7.9. - (18", CAP - .8 12.8 - . 32.0 -- Ovrland.' 5 9, 1.0 - : 2.5 - Varies -. - - '.49.9 Totals - - C 1 -- 2.1 5.3 -: Varies 2 - -- 14.9 - 373 . - . Overland - 5 3 - •• 3.8 - 9•55 - - 18" RCP ' 26.5. 4 '3:8 ' 9.5: - . V-ditch - - -. - . - 3.0, , 7.5 5 - - Ukbown - Totals ' 27.6. . . 'S • • -, ' ..- 5. - - . 5. -S - . - - •. 5 .- "S 5_' 5 ' S - S 5,, . S S' - S. 55 •S - - -6- TABLE 2-1 OF SUBAREAS (continued) Flow Generated Outlet Outlet Undersized a Area/Subarea' Acres (OF'S) Pipe Size Capacity Pipe @ 2.5 OF'S/Acre and Type (OF'S) Capacity/<18" D 1 12 9 32.3- 18" RCP 26.5 CAP 2 S 7.4 18.5 Varies - - - 3 1.3 3.3 Unknown J3 4 7 1.8 12" a1P 7.9 <18" 5 43 108 18"OMP 265 6 '13 33 ' 1811 (w, 265 7 -9 2.3 T 18" DIP 26. 5, 8 1.3 3.3 18" alP 26.5 9 5 13 Overland 30.6 ' ii Totals E 1 9 23 18"QIP 265 2.6 "' 6.5 '. 8" PVC 3.5 <18", CAP 3 SP 1.7 4.3 8" PVC 3.5 <18", CAP 4 14.9' 37.3 24" oT. 47.1 5 -, - 2.7 6.8 8" alP - 3.5 <18", CAP. ."8.8 SP 6 3.5 8" alP 3.5 <18", CAP 7 s 43 108 8" PVC 35 <18",CAP 8 37.9 94.8 24" PVC 47.1 CAP 9 S) 1.7 4 3 Overland - - - 10 69.5 173.8 -'- '30" CMP . - 7316 'CAP - lisp 1 1 2.8 Overland - - - 140.8 1 Totals a 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". - SP 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 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 on'es were either abandoned in place or utilized to carry water from smaller areas. Bluff Nil 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-1 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- . -- - S - •-._ - 5 - __5_• S. -- • . - S - - S - - 5• S 5 - - S. S S - . - S S - 5 - 5 " r I : - I . . .. .... . r .- ..-. L ME - .:.,.. . zg- ra - O N -- - . . ri . S 2 L\ - .- * 2 4. 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 Avenues at Carlsbad Boulevard The age of this pipe is undetermined Repairs are urgently needed at the out-let"".due to bluff erosion The bank appears 2 to --.-.;b e supported bY b the bamboo - .grow,th This pipe drops to the beach at Pine Avenue - 4 B-3 This subarea contains3 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 1 r - - fA - L - . - - Z 4t4!5 - 4 - - Aq U -. - - 4. - •'.. NL ± 211 " - -, .\ - -•• - ..' - f -- ---. .-•419 • 124 •- - 41 ( - I - 4 2; r 10 : : B-4 This subarea contains 3 4 acres The pipe is fed 7 I 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 winterof 1984 The outlet -is shown below 4 4 U - - 1• - VI • ,- p.- - F - ••• -'--- - t I 4. 1 - . .4. -- - - ,- -- - -. - - - -- s it .. --- - - -4- -4 -- - - f--- -4- -I - D ( * + -.• -.'- : -- ,- , - sk B-5 -This subarea contains 7 9 acres It is served,.by 'an 18".-AC outlet pipe The pip is feed by tw0 inlets, one on each side of Maple Avenue, -drops to4 4the ocean at Maple Aveiue The pipe was repaired and f erosionrei1led recently, as can be seen inthe picture below it - - I : : -: - 7 - - 55 • 5' 'S. - I 55A is S •S SS S• - - is. ' - - 555 S• - - - / - -, - -r - :} :i •• : S¼4. - - 1 k ' . 57 - is is •5, ___5 - 5' 'U - B-6 This subarea t contains 5 8 acres It"is served by an 18" PVC'pipe with 0-ring joints The pipe is fed by fourin1ets along the east side of Carlsbad Boulevard.-_:.,T outlet pipe was Lrepaired and-',-erosionf refilled during .-the winter of 1984 Thisipipe drops to the ocean Just south cif ',Acacia Avenue - - . Si•, ,.is -• ..... - ... ..B-7 5 .This. subarea -contains5.. acres..' It. is -served 4.by, S. - a 12" CMP outlet pipe The pipe is fed by a single inlet along Juniper Street and drops to the ocean atJuniper Street The outlet pipe is exposed, as can-'seen in th& pictures 'below .• -'-- '-: -•-.--: 5; 5555 7 5 •-f .:-Si --.,' .'' ''-''•'. 5; . -. - ¼ SSS45 S - - 5_•5 • 5,.S I , 12, -4 4 3 & 4 4 - ' : -.-: . :.. • -••.. 4.-. 4_ --..--,,. . I. ::' - . 4 . ' • - . - * 4 . • - 4• - . . 4$ e SOM RIM SOM -4- 4 14 , I - - - .4 4 4 .' 44 - -4 - 4t(_ •_" - ..- •t.f' 44 -4 4- - - - 4 - - -..A- '. - -c-- ç - - - B-B Thissubarea contains "12..-.8 acres Storm waters flow overland and follow the east side of Carlsbad Boulevard to Agua Hedionda - - - ;.-. •. 4. '-s. -4 - . - - -. - • . - r . - P - . B-9 This subareacontainsapproxirnately one-acre It is composed of -asmall strip of land along the west side of Carlsbad Boulevard There are-seven - storm drains which serve this area Although th& f ) contributing r h d drainage aea to eacrain is small, there still considerable erosion from 4is these drains .- *Also . ,there appear .to be some low spots in the Carlsbad Bou1evardcurb whicIa1low water to escapeover the side -of street and down the bluffs -The locatlon/ as well as a description of each drain, is listed below the following pictures of the drains - .- .**--..-,- . .*. 4 •-4j) '...- - . - .- 4 '13- - . - . - .- . . -_.• - B-9c 50' south of Sycamore 10" CMP B-9d 100' north of Maple 10" CMP -15- 0-~ 4, Area C Area C extends from the power p l a n t o u t l e t a t t h e s o u t h e n d of Agua Hedionda to Cerezo Dra i n . T h i s a r e a c o n t a i n s v e r y f e w storm drains and much of. the a r e a i s s i m i l a r t o A r e a A . A l a r g e portion of Area C has been de v e l o p e d w i t h s i n g l e f a m i l y h o m e s constructed on the bluff and m o s t o f t h e s t r e e t s . i n t h i s a r e a have curbs and gutters. The un d e v e l o p e d s e c t i o n s o f t h i s a r e a to the north need some impr o v e m e n t s t o p r e v e n t w a t e r f r o m running off Carlsbad Bouleva r d a n d o v e r t h e b l u f f s . H o w e v e r , there does not appear to be a m a j o r e r o s i o n p r o b l e m i n t h i s area. The drainage.basin east o f C a r l s b a d B o u l e v a r d w h i c h f l o w s overland needs improvements, but t h e s t o r m w a t e r f l o w s i n t o A q u a Hediorida and not onto the be a c h s o t h e r e i s n o t a b l u f f e r o s i o n problem. This area contains approximate l y 2 8 a c r e s a n d 5 s u b a r e a s . C-1 This subarea contains 2 . 1 a c r e s . is served by a 15" ..CMP and an 8" CMP o u t l e t p i p e . S t o r m water collects along the wes t s i d e o f C a r l s b a d Boulevard and flows northw a r d . T h e s e p i p e s appear to have been instal l e d w i t h h i g h w a y improvements. The outlet pipes a r e a p p r o x i m a t e l y 300' south of the power pla n t c o o l i n g w a t e r outlet bridge. The two outle t s a r e p i c t u r e d below. - ..-,- ...: a-• _;- -. -. - ;. '' '•.• -:. - -. • -. s-- _•• .- ;.-UNA ----"— ;' e '7-- :.:...i.. '... C-la 8" CMP OM J • . . -. - - - - - -- --- -- --•_.-*-_.-_•-•; - no ral"; . 93, Wq :i wofilll ;- - çJ IPA, e C-lb l5"CMP - - t C-2 This subarea contains 14.9. acres Storm water collects along the east side of Carlsbad Boulevard and flows overland to Agua dedionda C-3 This subarea contains 3..B' acres It is served - by án 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 38 acres, and is served by a broad concrete lined surface ditch The ditchalso'serves asa 4a1kway to the beach. The - -• - ditch was -installed with. subdivision' improve- - . •- --ments. - The' conôrete- -surfac .ditch seems: to - serve both fu.ntionswell' and'-the ystem 'could. - - - - solve problems in ot-het-'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. 8 {_ . '- '-p :- •--t '' - -. '- -.-,'- - - '- 8 - -• - :- :'- - ' -.-J -. -. .'. - - 19 8' - - '- - - .' • -• - - . - • - -- - - - - -, S•, •5' •5 . •5 5. 5 - - -- --- _ p .• . -. -A - •• ": - -- 9 5 - - • i - -! -• U - -. -J--- - 5. •44__;. - : :-: : • •'-4S --.: • ••• • •-. i:- fl - < 4 C5 This- subarea'-contains'3.0 'acres' and is now fully 4 developed with single .-family' dwellings. The outlet pipe is near the -"Southern end of.S'horè:- Drive Area D - Area D extends from CerezoDrive south to the Encinas Creek Bridge All larVd 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 €he- same time periodY 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 ir this area in the immediate future if improvements are not installed -' - •-• -.. ,,_ - -. - S - - _.•- 5,__ 5.-.; - • S., • . S ••--•- •. S . • S •5 S55.S .SS - -- - 5. - 5 - - .5 - .5. - `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 blu f f and enters three storm drains which carry it over the edge of the bluff. The Bluffs in this area are quite wide and th e 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 a has left some wide gullies in this area J 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-1 This subarea contains 12.9 acres. It is served by an 18" RCP whi,ch conveys storm water from the east side of Carlsbad Boulevard to the west side j of Carlsbad Boulevard. This pipe appears to have been instlled 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-1 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 01 -21- - '1p -;-1 2r cc .'t-'-..# • ,.- _,z . .'•?.--•' - I vr OKI- - 1•• .4_I I At .--.,. '? .'' \Ii-'c--•-- -- 'I' '-. - • ( * * 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 erosion because the is pipe is broken under the old roadbed The outlet pipe is Just csouth of the intersection of southbound Carlsbad Boulevard with the on ramp from Palomar Airport Road The outlet is shown - be low 4 - I! .. - 1. '. . . .. .:- -. (I - . • .-' .. . :- r - -J tU4- -i ..... i... . - wt - - / ORN - . . •. . ---': ;...- - / lit 4 ft D-6 This subarea co'ntains"l 3 acres, and is served by an 18" CM.P outletpipe The pipe- is fed by two inlets The outlet hasp 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 4. - -24- + 4 .4' . •• a -•••--.----•-•.' .•.'.-'. .-.-•.••',••-'.,•.-•- 4 - 4' 4•• •.• 4' .4 . -. .4' .4.. . 4 . •.. . . . . - . . •.. .• . 4. - 4 - 4. - . - _•t -4 . - ' ____I. "4- a '4 .— 4 - .. • - -V a * 0 4 . . V ,- 4,, '-4 - - 4 •-k •. .4 . -'? . --••-- . . •0 4 L - -.- a - -.4 4_I : D-7 This subarea contains 9 4.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 4.the outlet pipe I is covered with ice plant and is difficult to locate D-8 This subarea contains 1 3 acres It is served by 'A n 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 -8r idge The outlet 'is sIown below 4 --:-- 4_ .4 4, . V . .Y - -. 4 i••.__"_V,. ---V. 4 4 . -V .:.4 4 4.. C, •- - ::-'-' . - . 4 4 4.- 4 . 4 .4. . . 7 .44. a44 4'4. 1 4, 4- .4. VV 4•.4 444 •, - _._J, '•44.' • 444-4 -' - .4. -•4 9 41 it 4. •1, - 4..- .. . . -. .. . -4 ..- S. .;• - • -. 1- - • -. • - - •, P , • -- • --. • -4 . -S 4 •• . --S - ••,•-•-S ___4_• ,-•- . •- .- 4 • 4. -4 ,• -4 - .5-S . ., .5 •. 4 . .5 S.. .4' 44.4 4. '4 k VWPIU L T!J ' - - - '4.. - - - 4' 4 -.4. --.5 •__ 44 5.4-S '5 •• - 5 - .4' ••4 45.4444 -, • .4 4 4,• 4.. ,_44. .4 D-9 This subarea 4contains 5 acres It is a minor .- Z ubarea on the west side of the southbound line of Carlsbad4 Boulevard There are no stormdrain improvements in, this area and storm water f1ows overland Area E - 5 to All land in Area E adjacent the ocean is -part of the ',State..Park Area E xtends from Encinas Creek on the ,.,System .4 north to Batiquitos Lagoon on the south This area is entirely developed as a campground.,- -The ''4 bluff in this area is quite - high and all access m to 'the fro 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 '4 smaller than 18" is not effective- There has been substantial erosion from some .-,:of the..: smaller i,,storm drains, but the larger drains have caused little erosion - ., - ----- S • -.- ',.. 4'1 - .-, - - '4' •. ', 4 - . This ar45ea has'4 little need for emergency 4 repä'irs, but the.. area should have major improvements to prevent erosion in the, - 4 future.".,44 '',-' . :.,... 1 . ,• ... , 4.. 4. 10, '_4?' -4 •, 4* 44 '4- .4 • 4 .45 4 4- 5.. - 4,. - •5 •S.4 4.-S 44 , 5 - - .. 1 4'26 14 -- I •' - '•, -, . (This area has approximately 140 8 acres and is split into '10 subareas. •' - 4 - E-1 This subarea Oontains-,.9 acres.' It is served by an 18" CMP outlet pipe The pipe is currently fed 'one in1eo.'the es€'sidC of the southbound 'lanes of ;Carl'sbad"Boulev,ard. One pipe which -' continues east from this i'ilet, 15,yt -apears to be abandoned and not in service at this time The outlet is bbken',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 noi'thérriend-;of the, parking 'lot. The outlet is shown below.11 '4 4 ,-'- '4- '4' '44 'i"' - .4 -'4 .-,'t ., .-•:.,. , ', '-S -. - 4" 4-.-. -.-.-'-$ " ---- :--" -' - '4. - ,- -., :.4_ '4-. ',--',- '4 -4-.', - --'- hr 4 ,_• •4_ -- ,,,. ''4 - ' - 4. ••4' -- - .4 -'4 '4 '. ,4k 4 " ' - ' -. 4 * , -a.;,-. ''• - - I ' . '-.. -S -27>-4 '4 4- - '4-, '4.-, .4 - -. . 4 . ' -• 1 S. . • - - - - . S - - - : • • • - • • • - -o S - - - • - • S • • - - • -S - • S S • - • - -• - 5 -. • • S - S. -- S. -• - - S • - S. - •• S S - . •- S . • - . - - I • - - SI • I - S •_ S - -•_ - .- 0 r 4 1 , f ! TVXv la te- Rx MUM- So. ow I, - R 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 5.50' south of the northern end of the campground (Campspace 57) . The repairs are shown below. -29- , .. t I ) .., .,.'. .'.. ••i ....I - 4. S S - I - 4 - 5 4 - E-4 This subarea contains 14 9 acre It is served by a 241t CMP outletpipe The pipe is fed by four inlets:The..,subarea is composed of state park campground land, ar long section of Carlsbad Boulevard,,andl an area of vacant land on the east side of Carlsbad Boulevard There is evidence of erosion 1a1ong 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 Th6 outlet pipe is near the middle ofthe mobile home park -on,-*,"the east side of Carlsbad Boulevard (Campspace'-45) The outletis shown below r 4 V. - - £. - .• 4 I " 5- - .5- .4- 55• 45 155- 4. -. I_ - 5- - -30- AD I ; '4 4•5 .4I ' 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 '4 ,, 4... . . 4. . ' -- . :- ' ' '4 -, . * 4' - ,. - . -.4- -. !. S. 4 •I 44' '5 I - 4-> 4 '4 - .. . 4 .' -- S • - - - - .• 7 •• '4-' . . .-'-.- .•4--..• - '4 OEM - k It _3 - '.5 7' 4 - S *4.4 -4- .4 3. . 4 --- ' 34 4-4 • - - - - • -. '-7, - ......................... 4 '.4 .,4-- . 4, 4-'- 4- * .4 - -- ' - -•- - -- .4-. , 5 . . 4- - ..-• ••'. -- - 4 4- - - - -4 - - *4•4' - ' I - ,-,. -. - " '4 '- ., - .-. -I'-* , . - - - 4.4'•4. . ',> -4- •"44'4 - '4'5 5__ 4-' 4- '4 4 II - 1 - - - • S - • • - ._ -- . •5 -e - - - SS 0 • - S - - - S S S_s - - • - S - S • _S•. 0 :: aim •• •: :. • -. .; - :.: :::- 11 f. SWIM :• -. :- - '1 S. - . • - - - - S S 5 - - -• - -• - : • • •- S S • - • - - S S - -S S - - S - 0 S • S - - 0 -S - - S • S • • -• - -. - 5 - -S S • S - - S. -- .5 -. - - S . - •_ - 5• • S - 5 •- _S• S . - SI S • - 55 5 I - - • - I - - - _5. - - • 5 - 5 - -- 't -j - K - - - -. - IN •:'i:c : .- __:- Mot, - - ';.- - ,- - I I • - - •- k: '-5'- 3r ,-.-'3 - ( - ;-• '5 ;3 ._'_ ,_* 'e- - •• • - -, - - -i $'T- a r r E-8 This subarea contains 37 9 acres It is served by a 24" outlet pipe Thissubarea 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 (Campspace205) The outlet ' is shown below. 0, - -- ..•_—;. a ,. -.'--' - V.' V .', • a II YJ .- -V-"V- * a . - ! - . -- - ' . .' . - .- -•. -•a- - - . -- - - • - - V-I - - t - a,. -Vt.' - tV -- (• 'V. V - - --'Vs V. - -. . 'a: a- :ll Wit V 4. Vs a - — - eA E-10 This subarea contains 69 5 acres It is served by a 30" CM? 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 Bou1evard, the developed Ponto area, undeveloped land.,north and south of Ponto, and a 1arge 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 outletpipe is just south of the n Poto under- crossing (Campspace 168) The outlet is shown below . S., I -. - -S. S ..,• S • S -' S S - - .., $ 0 • 5 55 -- -• ., j - - er I 4 4.. . .rc t9 • —5 ._z_. ..- 0 ..sLSS — • 1555 — I Sac , 1 Is I I — 1$- — II sl - •tl - . - . .. -- - -., --• S $ - - - - - 5S - $ 5 5- '5 - •0 -50$ 5.5 - $ -- I $ •,- p $5 oSS55 — OL 5 55 - - fl - •- -.- - • 1 - --.-.- -- * • - - - -E-11 This subarea s contain 1 1 acres, and is no longer served by ap1pe The or pipe failed and has not been replaced The'storm water flows along the campground road to the corner of the and over the bluff maintenance,yard - + DO OR NNW - -' - - -J I- - ,---- • II •- - --- - - -- --- 11- - •- .- - - -. - • • II -- --- - -.- - -. U -•-- • - +•- -- :1 - -• •• •. , •,- •- • -•--' .• •..• I, •.--.• --- • - -7 111 -•; •_ - •, - -•, - : - I U4 ,••• • •• - • -• ---•' • .1 S 4, I • • , • •.- - • - 0 ' ••- • I -' U -. - - •.;I',• ' - - •-# -37- ;• s• 4 '-I-' ••0 •' ' V V V V Chapter 3 V V Bluff Erosion V V V V In surveying the storm drains along the coast,, it was V possible to see virtually all stages involved in the failure of V a storm drain. 'in the Carlsbad coastal area the failure of a storm drain causes. imrnediateerosion. Two major erosion forces, V , waves and storm water,. plague the coast. The results of each V type of erosion are easy to distinguish.' V V When wave action erodes the - bluff, the erosion is parallel to the coast. The waves undercut the bluffs, and large sections V fall into the ocean. This type -of erosion creates hig'h, steep V bluffs parallel 'to the coast line. This type - of erosion proceeds more rapidly when sand is absent from the beach. Since V the Carlsbad beaches have less sand each year, the wave erosion ,V V -problem is increased every year. V Thus,' as' the amount. of sand V has diminished, •the bluff' erosions due to wave action has V V V increased. V In contrast, storm' water erosion of the bluffs, occurs V ' perpendicular to the coast. Water running . over the bluffs rapidly erodes wide gullies and these gullies broaden and deepen V as they near the beach On a natural bluff very little water flows directly over' the bluff.'. Storm water would be directed LI . parallel to' the coast and enter the: beach area through major drainage courses. ' As 'develOpment ,has occurred storm drains have been installed to V collect storm water and . these drains have generally taken the '.shortest path to' the beach, which' is directly over the bluff's. These. storm drains have periodically V V'V 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 V drain approaches' the bluff. At the bluff', a sha'rp bend is 1U installed, with ,a very steep section' of 'pipe VdbWfl the bluff. An outlet structure is then installed on the end of the pipe' at the bottôm.of the bluff.' 'V V There are a number of reasonswhy a storm drain may 'fail, V ' but the following summarizes the general steps in ,the failure of a storm drain. The outlet of the storm drain is plugged, moved, or both,, by wave action causing the joints to leak Storm water " escapes from the' leaky joints and V ' rapidly erodes the steep fill around the pipe. , V The erosion undermines the 'pipe, eventually causing the pipe to collapse.'V , -38- 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 hig.her 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 it's .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 nurñber-'- 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 reloc,ated 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 ,ca'n 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,relocaté inlets - to allow ponding and storm drain - blockage will lead to water going over the bluff, surface drains' should be considered. Surface dr-ains-.would.al'so - 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.. Virtuallyall of. the 8" -drains in -the campground have failed. Also,' the erosion - ' - caused by the failure of small drains is,as severe - - - as -that --daused 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 tothe.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 fl 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 1st,. The repairs have also been divided into two groups by land ownership. All drains which begin and 'end on state park land are iis.tseparately. . S • Urgent Repairs City of Carlsbad Drains 'B-i 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: StateParkDr.ains ,. D-2 The three 'drains which serve this area should be reconstructed. The drains will soon collapse,, leaving the bluff: unprotected. Storm -water will cause rapid erosion on the unprotected slopes. 'The estimated cost for ,these repairs .is $50,000. E-5 The pipe which serves' this area has failed and will rapidly erode the, bluff. :The drain should be replacedand the slope refilled. The estimated. : cost for 'repair is $37,500. Other Needed Repairs ...There are , a '1arge number of 'drains which' need to be, repaired. Most of' the drains need to be refilled and new pipe installed. Table'4-l" lists. the 'drains and needed repairs. The table lists City. of Carlsbad' brains separately from State Park area 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. .The drains shouldbe expected to fail again,, since the original installation has failed. 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 REPAIRSJO EXISTING DRAINS a CITY OF CARLSBAD DRAINS Drain Description of Rpairs -• Cost D-5 Replace pipe, refill and rock outlet $ 37,500 Replace pipe, refill and rock outlet 37,500 • B-9g Refill pipe, rock outlet' S 15,000 D-6 Replace pipe, refill and rock outlet 37,500 E-4 Refill pipe, rock outlet • •' • 22,500 B-7 Replace pipe with 18", refill and rock arou n d 'outlet. • 37,500 B-9a Refill pipe, rock outlet 15,000 B-9b. Refill pipe, rock &itIet •• 15,000 LI B-9c • Rép.ace pipe, refill :ad rock 'outlet ••• 37,500 B-9d Refill pipe, rock outlet • 15,000 D-3 Locate pipe and repair 37,500 0-4 Replacepipe, refill and rock outlet .5 37,500 -- 0-7 Replace pipe, refill and rock outlet - • 22,500 . 0-8 : Replace pipe, refill and rock oUtlet I • 15,000 fl B-9f Refill and rock aroundoutlet • • 12,000 C-i Refill both pipes 7,500 B-5 RefilLand rock around outlet • •• • 7,500 -• 4 B-96 Refill and rock around outlet • . . 7,500 Subtotal $417,000 III -43- S -- • -- tllb TABLE 4,1 NEEDED REPAIRS TO. EXISTING DPINS a (continued) STATE PARK DRAINS 1• fl Drain Description of Repairs 0 E-6 Replace pipe with 18", refill and rock outlet E-9 Remove debris, refill, improve road drain E-ll Remove debris, refill, imprOve road drain E2b Replace pipe with 18", refill and rock outlet 1 E.3b Replace pipe with 18", refill and rock outlet E_7b Replace pipe with 18", refill and rock outlet 0 • : • Subtotal TOTAL a Drains are listed with those needing repairs the most first. • - • b These drains have recently been repaired. They are listed as needing repairs because the new • pipe is 8I and the minimum storm drain size should be 18t1. - 0 0 44 Cost $37,500 30,000 22,500 37,500 37,500 37,500 $202,500 $619,500 _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 cause d by stormwater. 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 1 Area A. The existing drains in this area are adequate and no new facilities are plannedt 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 M The drain will vary in size from 2411 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 Iover 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- Contributory Subareas . Location & Description of Improvements Total Acres Served Approximate, Flow Line Depth (feet) Costs (Thousands of Dollars) a Whale Watch Area (Flows South) B-i Ocean St. North of Pine Ave. 6.0 8 15 230' of 24" B-i- B-2 Carlsbad Blvd., Pine Ave.. to '10.7 13 46 Walnut Ave. 540' of 30" B-i thru B-3 Carlsbad Blvd , Walnut Ave 14.0 17 23 to Sycamore Ave. 220' of 36" B-i thru B-4 Carlsbad Blvd., Sycoré Ave. 17.4 19 66 to Maple Ave.' ' 630' of 36',' ' S 'B-i thru B-5 Carlsbad Blvd., Maple Ave. 25.3 21 , 71 to 140' So. of Acacia Ave. 470' of 42" B thru B-6 Carlsbad Blvd., 140' So of 31.1 .. 24 94 Acacia Ave to Juniper Ave 550' of 48" B-i thru B-7 Carlsbad Blvd., Juniper -Ave. 36.1 22 145 to Tamarack Ave. 850' of 48" B-1 thru 8-9 - Carlsbad Blvd., Tamarack Ave. ' 49.9 ' 10 112 ' - , to Agua Hedionda Lagoon 800' of 48" ' S Contributory Subareas Location & Description of Improvements Total Acres Served Approximate Flow Line Depth (feet) Costs (Thousands a of Dollars) Terra Mar Area (Flows North) D-1, D-2 Carlsbad Blvd , 470' So of 20.3 9 226 Cerezo Dr. to Cannon Road V V V 2,150' of 42" D-1, D-2 Carlsbad Blvd , Cannon Rd 35.2 9 225 and C-2 to 650' No of Power Plant Outlet. V : V 'V V 1,800 of 48" D-1, D-2 Carlsbad Blvd., 650' No of 37.3 5 44 C-2 & C-1 V Power Plant Outlet toAgua Hedionda Lagoon 3501 of 48" Subtotal 495 Palomar Airport Rd to Encinas Creek (Flows South) D-3 Southbound Carlsbad Blvd .1 .3 9 19 900' South of Manzano Dr to just North of paved loop adjacent to South- bound lanes of Carlsbad Blvd 350' of 18" D-3 & D-4 Southbound Carlsbad Blvd 2 0 11 30 just North of paved loop V V V to end of Palanar Airport Road onrip 500' of 18" D-3 thru D-5 Southbound Carlsbad Blvd .6 .3 13 52 end of Palanar Airport Rd oriramp to 800 South of orramp. V 800' of 24" -47- TABLE 5-1 SUMMARY OF COST FOR MASTER DRAINAGE sysrn,i (continued) - Approximate Costs Contributory Location & Description Total Acres Flow Line (Thousands Subareas of. Inrovnts ;. - Served Depth (feet) of Dollars) a 4 Palanar Airport Rd. to Encinas • Creek (Flows . . South) (con't) . . . . . D-3 thru D6 Southbound Carlsbad Blvd.. 7.6 12 30 800' South of. onrauip to . 1,160' North of Encinas Creek Bridge : • 430' of 27" D-3 thru D-7 Southbound Carlbad blvd. 8.5 7 33 • 1,160' North of Encinas Creek Bridge to 650' North of Bridge. 510' of 27" • • . D-3 thru D-9 Southbound Carlsbad Blvd. 10.3 5 42 • 650' North of Encinas Creek Bridge to Bridge.. . • 650' of 27" . • Subtotal • • 206 .1. I.-- I. •1 - 44 . . •-. . S. - TABLE:.5-1 SUMMARY OF COr FOR MASTER DRAINAGE ssri (continued) - Approximate Costs Contributory Location & Description Total Acres Flow Line (Thousands Subareas of Improvnts .: Served Depth (feet) of Dollars). ¶ . S • . S Northern Part of State Park Campground (Flows North) -. E.-4, E-5 . So.ithboundCarlsbad.Bliid 17.6. . 14 . .62 .5 - Campspace.45 to Campspace 57 .: 650' of 3V E-3 thru E-5 Southbound Carlsbad Blvd 19 3 19 97 . . . -Camjspace 57 to Campspace7O 720' of 42" S 5_. .. . 4 .4.. . . . E-2. thru E-5 .. Southbound Carlsbad Blvd. 21.9 •. . - 13 . 72 • Campspace-70 to 1,100feet . . -. . . .•. . North of Encinas Creek Bridge 600' of 42" -.. . . .,. . . E-1 thru E76 Southbound Carlsbad Blvd..22.8 5 74 1,100 feet North of Encinas .• . . '. ---. ..... . . Creek Bridge400feet: -to . -. .. . North of Bridge . . .. S. . .. .700 ' of 42" : . • '. .. . Subtotal - 349 Southern Part ' of State Park — Campground a - (Flows South). E-6 Southbound Carlsbad Blvd ! - 5 55 Campspace 12 to the - - - .- - e4._it.s'5 * * Campfire Center 1,000' of 18" S. - - - IX -, - . . •, - S.*S.5fr5. - - - i.A\x .WALL1EIS , IN , TABLE 5-1 SUMMARY OF COST FOR MASTER DRAINAGE SYSTaI (continued) ... Approximate Costs Contributory . Location & Description rotal Acres Flow Line (Thousands Subareas of Improvements H Served Depth (feet) a of Dollars) Southern Part of State Park Campground . (Flows South) E-6, E-7 Southbound Carlsbad Blvd. 7.8 . 8 62 Campfire center to Campspace 205 950' of 27" E-6 thru E-8 Southbound Carlsbad Blvd. 45.7 15 207 Campspace 205 to - Campspace 183 . . . 1,150 of 54" E-6 thru E-9 Southbound Carlsbad Blvd. 47.4 19 135- çanpspace 183 to . Campspace 168 750' of 54" : E-6 thru E-10 Southbound Carlsbad Blvd.,116.9 16 216 Campspace 168 to -Southern end of Campground maintenance. yard 900' of 72" E-6 thru E-ll Southbound Car1sbadBl,d. 118.0 9 240 Southern end of Campground. . maintenance yard to Batiqul- tos Lagoon Bridge 1,200' of 72" . . . . . . . 915 Subtotal TOTAL 21 537 a Costs include engineering -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. AreaD - 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 a's 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'S-i 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 : : -I - 72OOF42 oo or 42 SEE.FIGURE 5-3 ART OF 'GROUND AREA. I) - ILSON ENGINEERING FIGURE 5-2 / '.__80 . 18•• -650 OF 36 FOR CONTINUATION SEE FIGURE 5-2 NORTHERN PART OF STATE PARK CAMPGROUND AREA FLOW- (NORTH) 4. p iiiiiiiiij 1000' OF IS' FOR CONTINUATION SEE FIGURE 5-4 SOUTHERN PART OF STATE PARK CAMPGROUND AREA FLOw-Ø (SOUTH) MASTER STORMDRAIN FACILITIES WILSON ENGINEERING FIGURE 5-3 ______ I •et I low RIM Ir