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HomeMy WebLinkAbout3348; Poinsettia Park Sewer; Poinsettia Park Sewer; 1995-04-28CARLSBAD MUNICIPAL • WATER DISTRICT E I POINSETTIA PARK SEWER I CMWD PROJECT NO. 94-403 E RECOMMENDED ALIGNMENT REPORT C I I APRIL 28, 1995 I I I I • SUBMITTED BY: DANIEL BOYLE ENGINEERING, INC. I c DANIEL BOYLE ENGINEERING, INC. Civil Engineering Services CARLSBAD MUNICIPAL WATER DISTRICT April 28, 1995 5950 El Camino Real Carlsbad, CA 92008 Attention: Mr. William E. Plummer, P.E. District Engineer Carlsbad Municipal Water District Poinsettia Park Sewer CMWD Project No. 94-403 Recommended Alignment Report We are pleased to present herein our Recommended Alignment Report for the Carlsbad Municipal Water District (CMWD) Poinsettia Park Sewer. On April 7,1995 we completed and submitted to CMWD our Draft Alignment Study for the Poinsettia Park Sewer. That report included an analysis of three alternative alignments. Two of the alternative alignments, Alternatives A and B, included an analysis of each alternative with and without sewer service to the proposed Abada Costa Do Sol development located adjacent to and south of the proposed Poinsettia Park. The basis of the analysis for inclusion of the Abada development was that the connection manhole at the upstream end of the Poinsettia Park Sewer would have an invert elevation of 123.7-feet above sea level. This resulted in a maximum depth of the Poinsettia Park Sewer as it passed through the McReynolds property of 38.7-feet. On April 15, 1995 we received from CMWD written comments on our Draft Alignment Study and met with District Staff on April 19, 1995 to review the comments received. We were informed that the Abada development has revised the grading concept for their property to where the connection manhole would be raised by approximately 10-feet to elevation 133.0-feet above sea level. We were also informed that because of this and environmental concerns with Alternative Alignments B and D that the CMWD has decided to adopt Alternative A with inclusion of the Abada development as the project to be constructed. 3142 Vista Way, Suite 209 Oceanside, CA 92056 (619) 433-8710 FAX (619) 433-9709 CMWO - Poinsettia Park Sewer Project No. 94-403 - 4/28/95 - Page 2 We were directed to prepare this Recommended Alignment Report to describe the proposed alignment, developments to be served by the Poinsettia Park Sewer and the estimated construction cost of the project. Enclosed herein is our final Recommended Alignment Report for the Poinsettia Park Sewer. If you have any questions or need additional information, do not hesitate to call. NIEL BOYLE ENGINEERING, INC. Daniel B. Boyle, P.E Managing Engineer DBB:lam End. C15-101-00 RCMDALGN.RPT E I I CARLSBAD MUNICIPAL WATER DISTRICT POINSETTIA PARK SEWER CMWD Project No. 94-403 TABLE OF CONTENTS E G c c G c E I SECTION 1.0 2.0 3.0 4.0 5.0 PLATE NO. SERVICE AREA PAGE .. 1 RECOMMENDED ALIGNMENT 3 ENVIRONMENTAL CONCERNS/PERMITS/CEQA EASEMENTS 6 CONSTRUCTION COST ESTIMATES 1 SERVICE AREA & RECOMMENDED ALIGNMENT 2 PRELIMINARY PIPELINE PROFILE Follows Page 1 3 APPENDIX A DRAFT ALIGNMENT STUDY FOR POINSETTIA PARK SEWER, CMWD PROJECT NO. 94-403 Prepared By Daniel Boyle Engineering, Inc., Dated April, 1995 | c I 1 I I I 0 c I I c I i I i i 1.0 SERVICE AREA The service area for the Poinsettia Park Sewer is shown on Plate No. 1. The future developments will consist of four parcels including: Q McReynolds Property - Future Mar Vista Ql Future Hidden Valley Estates Ql City of Carlsbad - Future Poinsettia Community Park Ql Abada Property - Future Costa Do Sol The proposed Mar Vista development on the McReynolds property, as shown on Plate No. 1, includes the tentative sewer alignments within future streets with sewage flowing towards a cul-de-sac on the north side of the property. From the cul-de-sac, the sewer would connect to one of two existing interceptor sewers which parallels Palomar Airport Road and the Price Club property. Improvements for this tract have not yet been designed and are therefore, subject to change. The development includes 50 single family homes. The Mar Vista development proposes that 15-percent of the single family homes will include granny flats over the garages in order to meet its low income housing requirement. It is estimated that these granny flats will be equivalent to three additional single family homes from a sewage flow standpoint. The proposed Hidden Valley Estates development is east of Mar Vista and the future proposed street pattern and in-tract sewers are as shown on Plate No. 1. All of the sewage from Hidden Valley Estates can flow into the Mar Vista development. Hidden Valley Estates includes 60 single family homes. The proposed Poinsettia Community Park is south of the Mar Vista development. The proposed improvements to be constructed within Poinsettia Park are shown on Plate No. 1. The improvements that will contribute sewage flow to the Poinsettia Park sewer include two restrooms and a maintenance yard. The City of Carlsbad proposes to construct a gymnasium at some point in time in the future. It is estimated that the sewage flows from Poinsettia Park facilities, including the future gymnasium, will be equivalent to three single family homes. The proposed Costa Do Sol development is south of the Poinsettia Community Park. The future street pattern and in-tract sewers are as shown on Plate No. 1. Two alternative sewage flow patterns are possible from the Costa Do Sol development. The first alternative would include all 119 single family homes to be discharged into the Poinsettia C15-101-01 -1 - I I I I I I I I I I I I I SERVICE AREA & RECOMMENDED ALIGNMENT [^CO- INTERCEPTOR SEWERS SAMBI PROPERTY BRAMALEA PROPERTY (FUTURE HIDDEN VALLEY ROAD) CITY OF CARLSBAD MAINT. T FUTURE/POmSETTlA COMMUNITY PARK HIDDEN VALLEY ESTATES REStROOM • —^ /OrRESTROQM/ABADA PROPER FUTURE COST/ EXISTING LANDSLIDE McREYNOLDS PROPERTY FUTURE MAR VISTA PROPO^EB POIN SEWE EGEND PROPOSED SERVICE AREA PROPOSED POINSETTIA PARK SEWER ALIGNMENT PROPOSED FLOW DIRECTION ALTERNATIVE FLOW DIRECTION SEWER ALIGNMENT IN PROPOSED DEVELOPMENTS PAMPAS GRASS PLATE NO. 1 CARLSBAD MUNICIPAL WATER DISTRICT POINSETTIA PARK SEWER DANIEL BOYLE ENGINEERING, INC c c c c L L c £ £ CMWD - Poinsettia Park Sewer Project No. 94-403 Recommended Alignment Report - 4/28/95 Park Sewer near the northwest corner of the development. The second alternative would discharge 69 units to the Poinsettia Park Sewer and the other 50 units flowing south through an easement into an existing sewer located in Camino De Los Ondas. Table A below is a summary of the estimated sewage contribution to the Poinsettia Park Sewer on the basis of equivalent single family homes. TABLE A Development Mar Vista Hidden Valley Estates Poinsettia Community Park Costa Do Sol Total Alternative No. 1 53 60 3 119 - 22.55% - 25.53 - 1.28 - 50.64 235 • 100% Alternative No. 2 53 60 3 69 - 28.65% - 32.43 - 1.62 - 37.30 185 • 100% I C c E C15-101-01 -2- C E E E 1 E L E E i i E I I E E E CMWD - Poinsettia Park Sewer Project No. 94-403 Recommended Alignment Report - 4/28/95 2.0 RECOMMENDED ALIGNMENT On April 7,1995 a Draft Alignment Study for Poinsettia Park Sewer was submitted to the District. A copy of the Draft Study is included in Appendix A. Subsequently, the District was informed that the Costa Do Sol developers had revised the grading concept for their project which would raise the elevation of the discharge manhole to be connected to the upstream end of the Poinsettia Park Sewer by approximately 10-feet. Because of this and due to environmental concerns with Alternative Alignments B and D as investigated in the Draft Study, the District has selected Alternative A as the Recommend Alignment with modifications through Poinsettia Park and minor realignment between Palomar Airport Road and the Mar Vista development. The District's Recommended Alignment is shown on Plate No. 1. The preliminary profile of the Recommended Alignment is shown on Plate No. 2. Since the Abada discharge manhole has been raised by approximately 10-feet, the maximum depth of the Poinsettia Park Sewer as it crosses the McReynolds/Mar Vista property has been decreased from 38.7-feet to approximately 28-feet. This is still far deeper than normal sewer depths of 8 to 10-feet and will pose special problems to District Operations Personnel. District Engineering Staff has discussed these problems with Operations who has determined that they will be able to handle the special operational and maintenance difficulties associated with a sanitary sewer at this depth. District Engineering Staff has also discussed with Operations if a parcelled in-tract sewer should be constructed to sewer the individual homes or if the individual homes should be connected to the deep Poinsettia Park Sewer. The District has decided that the individual homes would be connected to the Poinsettia Park Sewer. The lateral design will be evaluated during the final design phase as will the method of determining the location of the stubbed off laterals when the actual individual homes are constructed in the future. If the Poinsettia Park Sewer needs replacement in the future, the District plans on a slipling process rather than the actual replacement of the pipeline itself. This will eliminate the major construction impacts which would otherwise result from replacement of a sewer at such a great depth. As shown on Plate No. 1, an existing landslide is located at the north end of the McReynolds property adjacent to and east of the Recommended Alignment. The District has retained Leighton and Associates, Inc., who have previously done geotechnical work on the McReynolds property, to evaluate any potential negative impacts due to the slide on the Poinsettia Park Sewer. This will be addressed in the final design. C15-101-01 -3- I I I I I I I I I I D e i i i i i B I PRELIMINARY PIPELINE PROFILE PROPERTY FUTURE MAR VISTA DEVELOPMENT *Z^ *s x8 <n *i o # 52 i*jo _in w COSTA DO SOL DEVELOPMENT EXISTING GROUND LINE PROPOSED FINISHED SURFACE SEWER FLOWLINE 10+00 14+00 RECOMMENDED PRELIMINARY PROFILE PROFILE SCALES: HORIZONTAL l"=300* VERTICAL l"=30' PLATE NO. 2 CA1LSBAD MUNICIPAL WATO DIST1ICT POINSITTIA PARK SKWK1 DANIEL BOYLX ENGINEERING, INC c c I n c c c I s CMWD - Poinsettia Park Sewer Project No. 94-403 Recommended Alignment Report - 4/28/95 The District considered elimination of Manhole No. 2 shown on Plate No. 2 because of the difficulties of getting an access road to this manhole. The District originally felt that if in the future the District saw a need for Manhole No. 2 that it would be constructed at that time. However after further reconsideration, it has been decided to install Manhole No. 2 during the original construction but seal off the manhole cover. The District's preference for pipe material is either AWWA C900 or ASTM D3034 PVC pipe. Each of these materials will be evaluated during final design as to their appropriate application for the Poinsettia Park Sewer. Also, the abrasive aspects of PVC pipe will be evaluated for the Poinsettia Park Sewer between Manhole Nos. 2 and 3 due to the steep 12 degree slope. The District has requested that all manholes deeper than 15-feet be designed with T-Lock interior lining. Also, the manholes are to be 60-inches in diameter which is standard District size. C15-101-01 -4- c c c 5 c fy C C E Near Palomar Airport Road the sewer will cross a creek. This will require a Corps of Engineers 404 permit. This permit will be applied for and processed by District Engineering Staff during design. C C c E fi e CMWD - Poinsettia Park Sewer Project No. 94-403 Recommended Alignment Report - 4/28/95 3.0 ENVIRONMENTAL CONCERNS / PERMITS / CEQA As part of the Draft Alignment Study for Poinsettia Park Sewer, copy attached in Appendix A, our environmental subconsultant RECON prepared Figure 3 which evaluates the existing vegetation and sensitive resources along the alignment of the alternative sewer alignments, including Alternative A. Figure 3 shows that at the south end of Alternative A the sewer would cross through a small portion of Coastal Sage Scrub. With the addition of Manhole No. 9 as shown on Plate No. 1 and realignment of Alternative A through Poinsettia Park, the alignment has been moved east and now clears the Coastal Sage Scrub. Also shown on RECON's Figure 3 at the north end of Alternative A adjacent to Palomar Airport Road, the sewer will pass through two small Southern Willow Scrub areas. This has been discussed with RECON and they have assured us that this will not be of any major concern to the Resource Agencies and mitigation measures, if any, will be very minimal. A coastal permit will also be required for this project and it too will be applied for and processed by the District. The CEQA process will also be completed by the District prior to proceeding with construction. i P C15-101-01 -5- CMWD - Poinsettia Park Sewer Project No. 94-403 Recommended Alignment Report - 4/28/95 4.0 EASEMENTS As shown on Plate No. 1, the Poinsettia Park Sewer crosses the City of Carlsbad Poinsettia Community Park, the McReynolds property and the Price Club property. District Engineering Staff has indicated that easements will not be required from the City of Carlsbad for crossing of the Poinsettia Park but will be required from McReynolds and Price Club. District Staff requested a permanent easement covering the pipeline and fairly wide construction easements. The actual widths of easements will be determined during the design phase of the Poinsettia Park Sewer. C C £ C C C I i I C C15-101-01 -6- c c c E C CMWD - Poinsettia Park Sewer Project No. 94-403 Recommended Alignment Report - 4/28/95 5.0 CONSTRUCTION COST ESTIMATE The following Table B is a construction cost estimate for the Poinsettia Park Sewer based upon recent construction bids for a similar project. TABLE B Item C E G 1. Sewer Pipeline: Station 10+00 to 13+30 2. Sewer Pipeline: Station 13+30 to 17+90 3. Sewer Pipeline: Station 17+90 to 33+80 4. Sewer Pipeline: Station 33+80 to 41 +60 5. Sewer Pipeline: Station 41 +60 to 45+20 6. Manhole Nos. 1 and 2 7. Manhole Nos. 3 through 11 With T-Lock 8. Manhole No. 12 9. Miscellaneous Appurtenances Quantity 330' 460' 1,590' 780' 360' 2 ea. 9 ea. 1 ea. LS. Unit Cost $54.00 75.00 117.00 91.00 54.00 3,800 8,100 3.800 LS. Estimated Cost $ 17,820 34,500 186.030 70,980 19.440 7.600 72.900 3,800 61.930 ESTIMATED CONSTRUCTION COST $475.000 C C c C15-101-01 -7- c c E C E 2 APPENDIX A DRAFT ALIGNMENT STUDY FOR POINSETTIA PARK SEWER, CMWD PROJECT NO 94-403 I• Prepared By: Daniel Boyle Engineering, Inc. L Dated: April, 1995 C i i : 2 - :. CARLSBAD MUNICIPALL WATER DISTRICT C I G G C E r DRAFT ALIGNMENT STUDY FOR " POINSETTIA PARK SEWER B CMWD PROJECT NO. 94-403 C C C i _ APRIL, 1995 SUBMITTED BY: DANIEL BOYLE ENGINEERING, INC. c E i E G CARLSBAD MUNICIPAL WATER DISTRICT DRAFT ALIGNMENT STUDY FOR POINSETTIA PARK SEWER CMWD Project No. 94-403 April, 1995 ry Prepared By:C DANIEL BOYLE ENGINEERING, INC. C E Daniel B. Boyle, P.E Project Principal i Jeffrey W. Ohmart, P.E. B Project Engineer CARLSBAD MUNICIPAL WATER DISTRICT POINSETTIA PARK SEWER CMWD Project No. 94-403 TABLE OF CONTENTS c c c E E C C c SECTION 1.0 2.0 2.1 2.2 2.3 3.0 3.1 3.2 3.3 4.0 4.1 4.2 5.0 6.0 7.0 7.1 7.2 INTRODUCTION PAGE . . 1 ALIGNMENT ALTERNATIVE A 2 Alignment Alternative A - With Abada 2 Alignment Alternative A - Without Abada 3 Environmental Considerations of Alignment Alternative A 3 ALIGNMENT ALTERNATIVE B 4 Alignment Alternative B - With Abada 4 Alignment Alternative B - Without Abada 4 Environmental Considerations of Alignment Alternative B 4 ALIGNMENT ALTERNATIVE D 6 Alignment Alternative D 6 Environmental Considerations of Alignment Alternative B 6 COST ESTIMATES PROJECT MATRIX 9 CONCLUSIONS AND RECOMMENDATIONS 11 Conclusions 11 Recommendations 11 APPENDIX A POINSETTIA PARK SEWER BIOLOGICAL TECHNICAL REPORT By Recon Regional Environmental Consultants : CARLSBAD MUNICIPAL WATER DISTRICT POINSETTIA PARK SEWER CMWD Project No. 94-403 LIST OF EXHIBITS - EXHIBITy 1.1 Proposed Sewer Alignments in Future Developments C 2.1 Alignment Alternative A With Abada M 2.2 Pipeline Profile of Alignment Alternative A With Abada r 2.3 Alignment Alternative A Without Abada 2.4 Pipeline Profile of Alignment Alternative A Without Abada C 3.1 Alignment Alternative B With Abada y 3.2 Pipeline Profile of Alignment Alternative B With Abada 3.3 Alignment Alternative B Without Abada 3.4 Pipeline Profile of Alignment Alternative B Without Abada C 4.1 Alignment Alternative D 4.2 Pipeline Profile of Alignment Alternative D 4.3 Cross Section Through Alignment Alternative D c I c L c c c i 1.0 INTRODUCTION The Carlsbad Municipal Water District is evaluating the backbone sewerage system for three separate proposed developments south of Palomar Airport Road near Price Club. The three proposed developments include Mar Vista, Poinsettia Community Park and Costa Do Sol, as shown on Exhibit 1.1. This exhibit also shows the proposed collection sewers in each of the developments. The proposed Mar Vista development on the McReynolds property shows the tentative sewer alignments within future streets with sewage flowing towards a cul-de-sac on the northwest side of the property. From the cul-de-sac, the sewer would connect to one of two existing interceptor sewers which parallels Palomar Airport Road and the Price Club property. Improvements for this tract have not yet been designed and are therefore, subject to change. Improvements for the City of Carlsbad Poinsettia Community Park have been designed as shown on Exhibit 1.1. The current plan for the sewer system is to gather flows from a maintenance yard, two restrooms, and possibly from adjacent developments, and direct flows to a sewer lift station to be located on the west side of the park. The lift station would pump the flow up a hill to the west and discharge to an existing gravity sewer located in Paseo Del Norte. The sewer system is currently designed to receive flow from the Costa Do Sol development to the south and possible from the Mar Vista development to the north. The sewer system for the proposed Costa Do Sol development on the Abada property is planned to take the majority of the flow out of the tract to the south. However, due to the existing and proposed grades in the development, a low spot will be generated in the northwest corner of the development. The current plan is to discharge this flow (generated from approximately 44 single family homes) to the Poinsettia Community Park sewer system for eventual pumping by the proposed sewer lift station. Carlsbad Municipal Water District would like to eliminate the need for the sewer lift station by constructing a gravity sewer line from the Poinsettia Community Park to one of the two existing interceptor sewers adjacent to Palomar Airport Road. This report evaluates three alternative alignments (referred to as Alignment Alternative A, B and D, respectively) for a gravity sewer line in lieu of a sewer lift station and variations on those three alignments. During the initial discussions of this alignment study, Alignment Alternative C was eliminated from consideration and is therefore, not addressed in this report. c C15-101-01 - 1 - D PROPOSED SEWER ALIGNMENTS IN FUTURE DEVELOPMENTS D 0 I I 0 I I I I 2 m I"S400' EXISTING INTERCEPTOR SEWERS BRAMALEA PROPERTY8AMBI PROPERTY (FUTURE HIDDEN VALLEY ROAD) LP MAINT. YARD HIDDEN VALLEY ESTATES ABADA PROPE FUTURE COSRESTROOM * LIFT STATION POSSIBLE SEWER CONNECTION POINT FOR FUTURE MAR VISTA McREYNOLDS PROPERTY FUTURE MAR VISTA „ CONNECTION TO EXISTING SEWER PRICE CLUB LEGEND SEWER ALIGNMENT IN PROPOSED DEVELOPMENTS PAMPAS GRASS EXHIBIT U CA1LOTAD MUNICIPAL WATUt D1ST1ICT FOmSKTTIA PA1K SEW11 DANIEL BOYLK ENGDfKKUNG, INC c C c E C C E E C I I I I CMWD - Poinsettia Park Sewer Project No. 94-403 - 4/7/95 2.0 ALIGNMENT ALTERATIVE A 2.1 Alignment Alterative A - With Abada Alignment Alternative A, with contribution of flows from the developed Abada property, would utilize a portion of the alignment as currently designed for the Poinsettia Community Park, the street alignment as tentatively planned for Mar Vista, and a connection to an existing manhole on the 30-inch San Marcos interceptor sewer, as shown on Exhibit 2.1. This alignment alternative would begin at the common property line of the Abada/Costa Do Sol property and Poinsettia Community Park. The required invert elevation at this point is 123.7-feet above sea level which is the low point in the Abada sewer system. Between manhole numbers 10 and 13, as shown on Exhibit 2.1, the flow would be reversed from what is currently planned and shown on Exhibit 1.1. As the sewer line continues north into the McReynolds/Mar Vista property, future grades force the sewer flow line to a maximum depth of 38.7-feet below future finished grades with average depth to the flow line being 34-feet below finished grade of the proposed tract, as shown on the pipeline profile Exhibit 2.2. As the sewer alignment exits the proposed Mar Vista tract to the north, the pipeline descends a steep slope and eventually intersects the existing interceptor sewer at a flow line elevation of 46-feet. The maximum depth of 38.7-feet to the flow line is over four times deeper than the normal sewer depth of 9-feet. This, in our opinion, will create future operations and maintenance problems. Also, some day this sewer pipeline will likely require replacement. Reconstruction of a sewer pipeline at this depth in a narrow residential street will be a major disruption to the residents living along the alignment of this sewer pipeline. Another major concern, and maybe the most important, is the health and safety of District personnel who will be required to maintain the pipeline. If District personnel are ever required to enter manholes at this depth, and most likely at some point in time they will, their health and safety will be compromised. In addition to the concerns listed above, a 38-foot deep sewer will require special considerations as to how the homes adjacent to the sewer will connect their laterals to a pipeline at this depth. Maintenance of laterals is also a factor to be considered. An alternative would involve a parallel sewer at normal 8 to 9-foot depth and connection of the parallel sewer to the deep sewer at the north end of the residential development. This alternative also has its problems such as if and when the 38-foot deep sewer needs to be repaired or replaced, the parallel sewer and other parallel utilities will most likely need to be removed and replaced during reconstruction of the deep sewer. This will be a major expense to the District rate payers. C15-101-01 -2- E C c C I I I I I I I I I CMWD - Poinsettia Park Sewer Project No. 94-403 - 4/7/95 2.2 Alignment Alternative A - Without Abada Should the Abada property not be developed or not contribute flow to this proposed gravity sewer, the entire complexion of Alignment Alternative A changes. As shown on Exhibit 2.3, the amount of sewer line required to be installed is shortened approximately 400-feet by removing flows from the Abada tract. The alignment of the sewer in Poinsettia Park can be changed as shown without impacting proposed improvements in the Park. As shown on Exhibit 2.4, eliminating flow from the Abada tract allows the proposed gravity sewer to be much shallower. The maximum depth from finished surface to the flow line of the sewer is approximately 17.2-feet from proposed finished surface and occurs in the Park. The depth of the sewer flow line in the proposed streets of Mar Vista is approximately 9 to 10-feet, which is slightly deeper than normal sewer depth. This alternative exits the Mar Vista tract and connects to the existing interceptor sewer to the north in the same manner as Alignment Alternative A - With Abada. 2.3 Environmental Considerations of Alignment Alternative A Recon Regional Environmental Consultants evaluated the biological resources within the alternative sewer alignments including a directed search for the Coastal California Gnatcatcher within native habitats along the proposed sewer alignments. The potential for sensitive habitats is primarily in the western portion of the McReynolds property and north of McReynolds property to Palomar Airport Road and Price Club. Future development of Poinsettia Community Park will remove any potential for sensitive species therefore, environmental considerations through the Park were not heavily emphasized in Recon's work. In summary, Alignment Alternative A would impact a small area of Coastal Sage Scrub, which is habitat to the California Gnatcatcher, near the boundary between Poinsettia Community Park and Mar Vista. The alignment would also disturb Pampas Grass and a small section of Southern Willow Scrub south of Palomar Airport Road. The Pampas Grass is considered a "disturbed area" and the Southern Willow Scrub was considered to have a low to moderate habitat quality. Gnatcatchers were not observed in the Coastal Sage Scrub traversed by Alignment Alternative A and Recon felt the Coastal Sage Scrub could be avoided in this area during final design. Overall, Recon estimated Alignment Alternative A would require mitigation of 0.15 acres. Recon's preliminary report is included in Appendix A. i C15-101-01 -3- I I I I I I I I I I I I I I I I 0 ALIGNMENT ALTERNATIVE A - WITH ABADA 8AMBI PROPERTY (FUTURE HIDDEN VALLEY ROAD) BRAMALEA iPROPERTY EXISTING INTERCEPTOR SEWERS CITY OF CARLSBAD FUTURE POINSETTIA COMAINT. YARDHIDDEN VALLEY ESTATES ABADA PROP ;TY FUTURE COil DO SOL PROPERTYMcREYNOLDS LEGEND PRICE CLUB PROPOSED POINSETTIA PARK SEWER ALIGNMENT ALTERNATIVE SEWER ALIGNMENT II1 PROPOSED DEVELOPMENTS PAMPAS GRASS EJLIUBU 2J DANHL BOYUE DfGINKDING, INC I CA1LSBAO MUNICIPAL WATM DIST1ICT PODrSKTTIA PA1K SlWHt I I I I I I I I I I I I I I I I I I I PIPELINE PROFILE PROPERTY FUTURE MAR VISTA DEVELOPMENT to *•o x 10 * * 2*. H*. _ *TT X o CO *X s FUTURE POINSETTIA COMMUNITY PARK t §lO£ to ss *X2s . . .8 1 *9J •5 < \ .... t *3; ^p "& S 6CMTi <to 1- IO *T-i +.Ol10 10 IsN ' <Ti Hto to ^ *X^g 55s « "H *tW 1-U. to lO * i 10oio S . 2II v>0)U. to Xs tf) j^ iX . JO < to .... wU. tf 8 ~VIll 1 t . . 1 *X o> 150 IIto 130FINISHED SURFACE SEWER FLOWLINE 10+00 42+00 46+00 ALIGNMENT ALTERNATIVE A - WITH ABADA EXHIBIT 2.2 CAJKLSBAP MUNICIPAL WATD DDTIICTPOUINB111A PAUL DANHL BOYLE BNGINEBB1NG, INC I I I I I I I I I I I I I I I I I I I ALIGNMENT ALTERNATIVE A - WITHOUT ABADA I-.400' EXISTING INTERCEPTOR SEWERS SAMBI PROPERTY BRAMALEA PROPERTY CITY OF CARLSBAD FUTURE POINSETTIA COMMUNITY raEH - MAINT. YARDHIDDEN VALLEY ESTATES ABADA PROPERTY McREYNOLDS PROPERTY FUTURE MAR VISTA PRICE CLUB LEGEND PROPOSED POINSETTIA PARK SEWER ALIGNMENT ALTERNATIVE SEWER ALIGNMENT IN PROPOSED DEVELOPMENTS PAMPAS GRASS EXHIBIT 13 CABL0BA9 MUNICIPAL WATE1 MBRICT FOUfSCTTIA PABE SBWD DANIBL BOTLK ENGDfKDING, INC I I I I I I I I I I I I I I I I I I I PIPELINE PROFILE PROPERTY FUTURE MAR VISTA DEVELOPMENT COj>- 4 <o 4k -i--IJ «^ FUTURE POINSETTIA COMMUNITY PARK O O 0 *X 5 X 2 0 H 111 (K CM FINISHED SURFACE SEWER FLOWLINE I 10+00 I 14+00 I 18+00 I 22+00 I 26+00 I 30+00 I 34+00 I 38+00 I 42+00 ALIGNMENT ALTERNATIVE A - WITHOUT ABADA EXHIBIT 2.4 CAKLSBAD MUNICIPAL WATB1 DDTUCTpommriA DANIEL BOYLI INOINKtING, INC I I I I G i C c E I I I I I CMWD - Poinsettia Park Sewer Project No. 94-403 - 4/7/95 3.0 ALIGNMENT ALTERNATIVE B 3.1 Alignment Alternative B - With Abada As with Alignment Alternative A, Alignment Alternative B with contribution of flow from the developed Abada property, would utilize a portion of the sewer alignment as currently designed for the Poinsettia Community Park, as shown on Exhibit 3.1. instead of following the future subdivision streets in the Mar Vista development, this alternative would traverse the back lot lines of the proposed development which is at the top of a steep slope. Rather than continuing north out of the Mar Vista development as with Alignment Alternative A, Alignment Alternative B would follow the alignment of an existing dirt road down the steep slope west of the Mar Vista development, then follow property lines west, then north to a connection point at an existing manhole on the interceptor sewer adjacent to Price Club. The pipeline profile for this alternative is shown on Exhibit 3.2. As can be seen, the maximum depth of the sewer flow line is 35.8-feet, which occurs within the Mar Vista development. This alignment through the Mar Vista development will put the pipeline in or adjacent to the backyards of future homes. This in and of itself creates maintenance problems and liability issues for the District. Compounded by the extreme depths of the sewer, this alternative becomes the least desirable of the alternatives discussed. Replacement of the sewer in the future will be far more difficult and costly than any other alternatives. Also, health and safety of maintenance personnel, as well as the homeowners, will be as high or higher than the risks for the other alternatives. 3.2 Alignment Alternative B - Without Abada Without the contribution of flow from the Abada property, the length of sewer required in the Park can be reduced and the alignment changed, as shown on Exhibit 3.3. The depth of the sewer through the Mar Vista development is also reduced as shown on Exhibit 3.4. The maximum sewer flow line depth is approximately 17.2-feet and occurs within the Park. Although the pipeline is shallower in Alignment Alternative B without flow from the Abada property, the maintenance and liability issues associated with a sewer pipeline in or adjacent to the backyards of homes is not diminished. 3.3 Environmental Considerations of Alignment Alternative B As shown in Recon's report in Appendix A, Alignment Alternative B traverses a greater amount of sensitive habitat than Alignment Alternative A. The existing dirt road that runs west down the slope from the future Mar Vista development has been overgrown with Coastal Sage Scrub. Coastal Sage Scrub is a potential habitat for the Gnatcatcher however, Gnatcatchers were not observed along Alignment Alternative B. Once the pipeline is off the McReynolds property, the alignment traverses Southern Willow Scrub C15-101-01 -4- ™ CMWD - Poinsettia Park Sewer Project No. 94-403 - 4/7/95 to the connection point of the interceptor sewer adjacent to Price Club. Recon estimates the total acreage requiring mitigation along Alignment Alternative B is 0.87 acre. I [ E C I I I I I e 1 C15-101-01 -5- D D fl I I I ALIGNMENT ALTERNATIVE B - WITH ABADA I D y o P l"»400f EXISTING INTERCEPTOR SEWERS 8AMBI PROPERTY (FUTURE HIDDEN VALLEY ROAD) BRAMALEA PROPERTY CITY OF CARLSBAD FUTURE POINSETTIA COMMUNITY PARK i ffl" "^EH MAINT. YARDHIDDEN VALLEY ESTATES RESTRTJOM PARKING LOT RESTROOM FUTURE COSTA DO SOLJA McREYNOLDS PROPERTY PRICE CLUB LEGEND PROPOSED POINSETTIA PARK SEWER ALIGNMENT ALTERNATIVE SEWER ALIGNMENT IN PROPOSED DEVELOPMENTS EXHIBIT 3d CA1LMAP MUNICIPAL WATUt DIST1ICT FOUIBBll'lA PAIK SIWO DANIIL IOTLB ENGINUIING, INC I I I I I I I I 0 D I I I I I I I I I PIPELINE PROFILE J PROPERTY FUTURE MAR VISTA DEVELOPMENT N # «0 I•u. v C X c X FUTURE POINSETTIA COMMUNITY PARK I o *' x 1 N•A ^ 10+00 14+00 22+00 26+00 30+00 34+00 38+00 42+00 I 46+00 160 FINISHED SURFACE SEWER FLOWLINE I 50+00 ALIGNMENT ALTERNATIVE B - WITH ABADA EXHIBIT CAMMBAP MUNICIPAL WATU DIOTtlCTPODfSnTIA PA1K SEWE1 DANIEL BOYLK KN6INIBBINC, INC I I I I I I I I ALIGNMENT ALTERNATIVE B - WITHOUT ABADA B I I I D D I r.400' EXISTING INTERCEPTOR SEWERS 8AMBI PROPERTY BRAMALEA PROPERTY CITY OF/CARLSBAD FUTURE POINSETTIA COMMUNITY H3 ] MAINT. YARDHIDDEN VALLEY ESTATES ABADA PROPERTY LEGEND PROPOSED POINSETTIA PARK SEWER ALIGNMENT ALTERNATIVE SEWER ALIGNMENT IN PROPOSED DEVELOPMENTS EXHIBIT 3.3 CAilOTAP MUNICIPAL WATM DOTUCTETTIAPAV8KWU DANBL BOTLI BNGDflUINO, INC I I I I I I I I PIPELINE PROFILE D D I I D D D PROPERTY FUTURE MAR VISTA DEVELOPMENT N 00 FUTURE POINSETTIA COMMUNITY PARK M» 0o»v 0 s * * X_ «e *X HwUJ OC FINISHED SURFACE SEWER FLOWLINE 10+00 34+00 38+00 42+00 I 46+00 D 1 ALIGNMENT ALTERNATIVE B - WITHOUT ABADA EXHIBIT 3.4 CAlLiMAP MUNIOPAL WATH DISTBICTPWNSEITIA PA1K 8BWU DANHL BOYLE ENGINIUING, INC C I L C i C C I I I I I CMWD - Poinsettia Park Sewer Project No. 94-403 - 4/7/95 4.0 ALIGNMENT ALTERNATIVE D 4.1 Alignment Alternative D Alignment Alternative D is per the sewer alignment as originally designed in the Park and parallels the southern and western McReynolds property line. Alignment Alternative D nearly follows the natural fall of grades between the Park and existing interceptor sewer, as shown on Exhibit 4.1. The advantage of this alignment is that whether flow is received from the Abada/Costa Do Sol development or not the sewer pipeline profile does not change, as shown on Exhibit 4.2. The maximum depth of the sewer flow line is approximately 20-feet which occurs as the pipeline traverses the valley east to west and crosses a creek in the middle of the valley floor. The disadvantage of this alignment is that as the sewer parallels the western McReynolds property line it is in a 2:1 slope for a portion of this section of the alignment. This would require construction of a 5-foot high retaining wall approximately 750-feet in length. Although the cost of constructing a sewer pipeline in this alignment is increased by constructing a retaining wall for a portion of the alignment, the retaining wall would provide for a level surface for all weather access. Exhibit 4.3 shows a cross section through the valley on the McReynolds property. 4.2 Environmental Considerations of Alignment Alternative D Much of Alignment Alternative D crosses Coastal Sage Scrub and Southern Willow Scrub. The environmental investigation by Recon found that the Coastal Sage Scrub along Alignment Alternative D was supporting the Gnatcatcher. Two to three birds were observed along this alignment on three separate field visits during Recon's study. Mitigation along Alignment Alternative D is estimated at 0.51 acre. Recon's report states that the impact along Alignment Alternative D could be minimized by pushing the north-south section of the alignment through the McReynolds property further east. This is essentially Alignment Alternative C which was dropped from consideration during the early discussion stages of this project with the District. i C15-101-01 -6- I I I I I I I I I I B ALIGNMENT ALTERNATIVE D r.4001 EXISTING INTERCEPTOR SEWERS BRAMALEA PROPERTY3AMBI PROPERTY (FUTURE HIDDEN VALLEY ROAD) CITY OF CARLSBAD FUTURE POINSETMAINT. YARD COMMUNITY PARK 3LHIDDEN VALLEY ESTATES ABADA PROPERTY FUTURE COSTA DO SOL -—'MH #8 McREYNOLDS PROPERTY FUTURE MAR VISTA LEGEND PRICE CLUB PROPOSED POINSETTIA PARK SEWER ALIGNMENT ALTERNATIVE SEWER ALIGNMENT IN PROPOSED DEVELOPMENTS EXHIBIT 4.1 CA1L8BAD MUNICIPAL WATH IHCTUCT C1TIA PABK 8EWK1 DANBL BOTLB tNGIfflDINO, INC I I I I I I I I I D PIPELINE PROFILE I I I I I I I I PRICE CLUB DEVELOPMENT WEST OF McREYNOLDS PROPERTY 10*00 CITY OF CARLSBAD FUTURE POINSETTIA COMMUNITY PARK s= *X2 cn c$ t M ^ •a < 1 • fc1 VI L CM *i 3 IO K) 6 •w <Ti H-w) W 11. "^x^ 10 *X roN •o • • • * 3. .<TT 1—(/) (/)b. — *X 8 r- ? II h~ch ' • • • wu. — ^^ 1C (TK iVU I to *^e |Q ! » 1 . ?^1 •< 01 O ^CMnwU.FINISHED SURFACE SEWER FLOWLINE 42+00 46+00 ALIGNMENT ALTERNATIVE D EXHIBIT 4.2 CA1L81AP MUNICIPAL WATK1 DI8T1ICTFO1NSB1TIA PABK 8IWBK DANHL BOTLK ENODfEBBING, INC I I I I I I I I I 0 D I I I I I I I I CROSS SECTION THROUGH ALIGNMENT ALTERNATIVE D RESIDENTIAL DEVELOPEMENT 5' HIGH (MAXI RETAINING WALL |750'i MAX) WITH FENCE— i \ I I \ I f\ u\ U.10'.\ tt\tf i X 2E So DCO i 1\ \/ ^ f/ \ ] UJ H , m LJ i r& McREYNOLDS PROPERTY POSSIBLE FENCE TO PREVENT ACCESS TO SENSITIVE SPECIES AREA SENSITIVE SPECIES AREA CULTIVATED AGRICULTURAL FIELDS PAVED OR DO ALL WEATHER ROAD FOR DISTRICT MAINTENANCE GRAVITY SEWER ALTERNATIVE D SECTION A-A EXHIBIT 43 CA1LCTAP MUNICIPAL W ATM DIST1ICTptwrarnriA PAIK siwn DANBL BOTLI KNGDfUUNG, INC C CMWD - Poinsettia Park Sewer Project No. 94-403 - 4/7/95 5.0 COST ESTIMATES Table No. 1 lists the estimated construction costs for each of the alternatives. As shown, construction costs for Alignment Alternatives A and B are the most expensive while construction cost for Alignment Alternative D is least expensive, when flows are contributed by development of the Abada property. When flows are not contributed by development of the Abada property, Alignment Alternative A is the least expensive and Alignment Alternative D is the most expensive. It should be noted that lift station costs to serve Abada if not served by the sewer and environmental mitigation costs are not included in the construction cost estimates. Inclusion of these costs could have a significant impact on the total estimated construction cost and ranking for each alternative. E C I E I I I C15-101-01 -7- CMWD - Poinsettia Park Sewer Project No. 94-403 - 4/7/95 PL Table No. 1 CARLSBAD MUNICIPAL WATER DISTRICT POINSETTIA PARK SEWER Construction Cost Estimates c c Alignment Alternative A With Abada 1. Pipeline 2. Manholes 3. Miscellaneous (15%) Quantity 3,595-Feet 16-Each L.S. Total Cost $372,375 69,000 66.225 $507.600 E Alignment Alternative A Without Abada 1. Pipeline 2. Manholes 3. Miscellaneous (15%) 3,210-Feet 9-Each LS. Total $240,750 30,000 40.750 $311.500 C Alignment Alternative B With Abada 1. Pipeline 2. Manholes 3. Miscellaneous (15%) 4,085-Feet 16-Each LS. Total $439,156 72,000 76.750 $587.900 I I i Alignment Alternative B Without Abada 1. Pipeline 2. Manholes 3. Miscellaneous (15%) Alignment Alternative D 1. Pipeline 2. Manholes 3. Retaining Wall 4. Miscellaneous (15%) 3,380-Feet 10-Each LS. Total 2,580-Feet 8-Each 750-Feet LS. Total $253,500 33,000 43.000 $329.500 $259,500 51,000 75,000 58.460 $443.500 C15-101-01 -8- E E C E E C C C C C i i i i i CMWD - Poinsettia Park Sewer Project No. 94-403 - 4/7/95 6.0 PROJECT MATRIX A project matrix ranking advantages and disadvantages of each alignment alternative is presented in Table No. 2. This ranking does not include environmental mitigation and Abada lift station costs. The result of the ranking in descending order from most desirable to least desirable is as follows: Alignment Alternative A Without Abada Most Desirable Alignment Alternative B Without Abada Next Most Desirable Alignment Alternative D Next Most Desirable Alignment Alternative A With Abada Next Most Desirable Alignment Alternative B With Abada Least Desirable C15-101-01 -9- c c E E E E E E E C 1 G i I I E i CMWD - Poinsettia Park Sewer Project No. 94-403 - 4/7/95 Table No. 2 CARLSBAD MUNICIPAL WATER DISTRICT POINSETTIA PARK SEWER Preliminary Project Matrix1.ID CONSIDERATION 1 . Operations & Maintenance 2. Future Replacement 3. Worker Safety 4. Manhole Access 5. Repairs 6. Environmental Issues 7. Construction Cost 8. Easement Acquisition 9. Resource Agency Approval TOTAL AH. A With Abada 2 2 2 2 2 4 1 4 4 23 Alt. A Without Abada 5 5 5 5 5 5 5 5 5 45 Alt. B With Abada 1 1 2 2 2 2 2 2 2 16 Alt. B Without Abada 3 3 4 3 3 3 4 3 3 29 Alt. D 4 4 4 4 4 1 3 1 1 26 (1)RATING POINTS (1 TO 5) 1 = Least Desirable 5 = Most Desirable C15-101-01 -10- E C I I I I I I I I I I I I I B CMWD - Poinsettia Park Sewer Project No. 94-403 - 4/7/95 7.0 CONCLUSIONS AND RECOMMENDATIONS 7.1 Conclusions Clearly, Alignment Alternative A without Abada is the preferred alternative from an engineering standpoint, a construction cost standpoint and an environmental standpoint. However, development of the Abada property as it is currently envisioned would require construction of a lift station. When flow is contributed to the system by the Costa Do Sol development on the Abada property, the preferred alternative is not so clear. From an engineering and construction cost standpoint, Alignment Alternative D is preferable however, from an environmental standpoint Alignment Alternative D is least desirable. If the costs of mitigation are included in the project costs, Alignment Alternative D may no longer be preferred due to the total project cost. Due to the environmental concerns and potential mitigations, Alignment Alternative A may become preferred over Alignment Alternative D. If development on the Abada property is going to contribute flow to this sewer system, the disadvantages of constructing a sewer lift station versus the disadvantages of Alignment Alternatives A and D need to be revisited. 7.2 Recommendations Comments regarding the alignment alternatives have not yet been received from the resource agencies. Recommendations will be included in the report after the resource agencies have had an opportunity to offer input to the project. C15-101-01 -11- I I I I APPENDIX A • POINSETTIA PARK SEWER _ BIOLOGICAL TECHNICAL REPORT By Recon Regional Environmental Consultants i I I I I I I I POINSETTIA PARK SEWER Biological Technical Report 1 i E E E March 1995 E E 1 BIOLOGICAL RESOURCE REPORT FOR POINSETTIA PARK SEWER I CARLSBAD MUNICIPAL WATER DISTRICT I • Prepared for - DANIEL BOYLE ENGINEERING, INC. | 23231 SOUTH POINTE DRIVE, SUITE 103 LAGUNA HILLS, CA 92653 C i P Prepared by I RECCDN I e Regional Environmental Consultants 7460 Minion Valtoy Ro»d, San Diego, CA 92108 (619) 542-1611 RECON NUMBER 2690B MARCH 21,1995 This document printed on recycled paper. TABLE OF CONTENTScIntroduction 1 I Methods 1 • Existing Conditions 1 A. Botany 5 | B. Zoology 7 C. Sensitive Resources 7 Impact Analysis 9 I A. Habitat 11 B. Sensitive Species 11 jy C. Jurisdictional Waters and Wetlands 11 • D. Steep Slopes 11 Recommendations 12 I, A. Avoidance and Minimization 12 _ B. Mitigation 12Bi References 13 FIGURES H 1: Project location in San Diego County 2 ™ 2: Project location in city of Carlsbad 3 3: Existing vegetation and locations of sensitive resources and alternative H sewer alignments 4 TABLE I 1: Summary of Impacts 10 • ATTACHMENTS 1: Plant species observed p 2: Wildlife species observed I E I I I I 1 I 1 E I Introduction The Carlsbad Municipal Water District plans to construct a sewer pipeline that would extend from Palomar Airport Road near Price Club southerly to the proposed Poinsettia Community Park (Figures 1 and 2). The purpose of the project is to provide sewer service to the proposed park and adjacent land owners and eliminate other costly alternatives (i.e., sewage lift station). This report describes the biological resources present along three alternative pipeline alignments, presents the results of an impact analysis of the project on biological resources, and provides recommendations for avoiding, minimizing, and mitigating potential significant impacts to biological resources. Methods A general botanical survey was conducted along the alternative sewer alignments and the surrounding area on February 10,1995. Vegetation communities were mapped and a list of plant species observed was compiled. Since the survey was conducted in late winter, annual plants that bloom during the spring and summer months may not have been detected. A general wildlife survey was conducted on February 3, 1995, in conjunction with directed surveys discussed below. Directed surveys were conducted for coastal California gnatcatchers on February 3, 10, and 17, 1995, in accordance with the terms and conditions of RECON's endangered/threatened species permit (#PRT-797665). Surveys covered all areas of appropriate (even marginally/questionably appropriate) habitat on-site. Tape recordings of gnatcatcher vocalizations were played to elicit calling responses. These taped vocalizations were played approximately every five minutes, or at the surveyor's discretion when a reasonable distance had been covered since the last playing of the tape. Weather conditions during the surveys ranged between 59° Fahrenheit (F) and 74° F, with winds between 0 and 5 miles per hour, and up to 80 percent cloud cover. All surveys were conducted between 7:00 and 11:30 A.M. During the directed gnatcatcher surveys, notes were taken on other species observed or detected.I 1 Existing Conditions I The following sections describe the plants, animals, and sensitive resources observed in B the study area. Vegetation, sensitive species sightings, and the three alternative sewer _ alignments surveyed are shown on Figure 3. I i I I I I c E 1 i I I OCEANSIDE BUENA VISTA LAGOON AGUAHEDIONDA LAGOONCARLSBAD PROJECT LOCATION • f LAKE SAN MARCO! LEUCADIA ENCINITAS 2 MILES 0 FIGURE Regional Location of the Project RECQN (FUTURE HIDDEN VALLEY ROAD) CITY OF CARLSBAD FUTURE POINSETTIA COMMUNITY PARK 500 FEET 0 FIGURE 2 Project Site Baccharis scrub Southern willow scrub Southern mixed chaparral Chamise chaparral Coastal sage scrub Pampas grass Disturbed/agriculture C - Ceanothus verrucosus -D Dichondra occidentalis ^— Sewer alignment 500 250 FEET 0 FIGURE 3 Existing Vegetation, Sensitive Resources and Sewer Alignments (A,B> and D) i E c c I I 1 I E A. Botany Four native plant communities and three disturbance communities occur in the study area. The locations of the communities described below are shown on Figure 3. A complete list of plant species observed on the site is given in Attachment 1. 1. Diegan Coastal Sage Scrub Coastal sage scrub habitat in this area is dominated by California sagebrush (Artemisia californicd), black sage (Salvia mellifera), California buckwheat (Eriogonum fasciculatum), laurel sumac (Malosma laurina), and lemonadeberry (Rhus integrifolia). The plant community occurs on the east-facing slope of the southern end of the main canyon on the site, and along the east- and west-facing slopes towards the northern end of the canyon (see Figure 3). Pampas grass (Cortederia selloand) occurs in the coastal sage scrub habitat on the west-facing slope at the northern end of the canyon. Habitat quality of the coastal sage scrub habitat on the site is, in general, moderate to high. Alignment A crosses a small portion of coastal sage scrub habitat; Alignment B crosses coastal sage scrub habitat, especially as it descends down to the canyon bottom on the north end; and Alignment D crosses coastal sage scrub habitat along the entire length of the east-facing slope below the condominiums. 2. Southern Willow Scrub Dominated by red willow (Salix laevigatd) and mule fat (Baccharis salicifolid), this plant community is confined to scattered locations on the drainage bottom of the north-south canyon and as a large woodland at the mouth of the canyon and in Encinas Creek (see Figure 3). Other plants found in this habitat type on the site include curly dock (Rumex crispus), cocklebur (Xanthium strumariwri), poison hemlock (Conium maculatum), and pampas grass, especially in the understory of the woodland area. The habitat quality of the willow scrub areas of the property are low to moderate due to small habitat patch size in the canyon and invasion of pampas grass in the understory of the woodland area. Alignment A crosses a small area of this habitat just south of Palomar Airport Road; Alignment B crosses through the large willow woodland stand at the north end of the canyon; and Alignment D also crosses through the willow woodland at the north end of the canyon, but west of Alignment B. 3. Southern Mixed Chaparral This habitat occurs on the north-facing slope east of the mouth of the small canyon (see Figure 3). The area burned in the recent past, and the area is recovering from the disturbance. Dominant plant species observed include lemonadeberry, laurel sumac, black sage, bush monkeyflower (Mimulus aurantiacus), and blue elderberry (Sambucus I I I i I E C E E C I! mexicana). Habitat quality of this community is low to moderate due to the past fire, invasion of pampas grass, and use of the area by migrant workers. Alignment A crosses through disturbed southern mixed chaparral as it descends down the north-facing slope above Encinas Creek. This area of the mixed chaparral is heavily infested with pampas grass. 4. Chamise Chaparral A small patch of chamise chaparral is found on the west-facing slope near the central part of the canyon (see Figure 3). This area is dominated by a nearly pure stand of chamise (Adenostoma fasciculatum). Habitat quality is moderate due to small patch size and disturbance from migrant workers. None of the proposed sewer alignments cross this habitat type. 5. Disturbed Areas Three community types are classified under disturbed for this report: agricultural lands, baccharis scrub, and pampas grass. The agricultural fields on the site were producing tomatoes. Fields that have been fallow towards the south portion of the study area and east of the canyon were vegetated with primarily non-native species. The non-native plants include black mustard (Brassica nigrd), tocolote (Centaurea melitensis), foxtail chess (Bromus madritensis ssp. rubens), smooth brome (Bromus hordaceus), and radish (Raphanus sativus). Habitat values of these area is considered low for native wildlife and plants. The majority of Alignments A and B cross active and fallow agricultural fields. The southern third of Alignment D crosses fallow agricultural fields. Baccharis scrub habitat occurs in the flat portions of the canyon adjacent to the drainage course. This plant community is dominated by coyote bush (Baccharis pilularis) with other co-dominant species such as blue elderberry, sweet fennel (Foeniculum vulgare), and coast goldenbush (Isocoma menziesii). Habitat quality of this community is moderate because of the dense shrub cover. Alignment D crosses through this habitat as it traverses the small canyon. Pampas grass has invaded the slopes and canyon bottom of Encinas Creek at the north end of the project area, south of Palomar Airport Road (see Figure 3). Dense stands of this species with sea fig (Carpobrotus edulis) cover a large area to the exclusion of most other species. Habitat quality of this community is generally considered low. Alignment A crosses through a dense stand of pampas grass south of Palomar Airport Road before traversing Encinas Creek. 1 I I i G i G C i C D B. Zoology A total of 22 bird species, 7 mammal species, and 1 amphibian species were observed or detected on the property. Typical wildlife species encountered or detected during the surveys include yellow-rumped warbler (Dendroica coronatd), wrentit (Chamaea fasciatd), California and rufous-sided towhee (Pipilo crissalis and P. erythropthalmus, respectively), scrub jay (Aphelocoma coerulescens), song sparrow (Melospiza melodia), house finch (Carpodacus mexicanus), coyote (Canis latrans), and racoon (Procyon lotor). A complete list of wildlife species observed is provided in Attachment 2. C. Sensitive Resources For purposes of this report, species will be considered to be sensitive if they are (1) listed by state or federal agencies as threatened or endangered or are candidates or proposed for such listing; (2) on Lists IB or 2 of the California Native Plant Society's (CNPS) Inventory of Rare and Endangered Vascular Plants of California (Skinner and Pavlik 1994); or (3) considered rare, endangered, or threatened by the Natural Diversity Data Base (NDDB) (State of California 1994) or local conservation organizations or specialists. Noteworthy plant species are considered to be those which are on Lists 3 and 4 of the CNPS Inventory. Sensitive habitat types are those identified by the California NDDB (Holland 1986). Assessments for the potential occurrence of sensitive or noteworthy species are based upon known ranges and habitat preferences for the species and species occurrence records from the NDDB. Locations of sensitive biological resources are noted on Figure 3. 1. Wildlife Sensitive wildlife species observed on-site were coastal California gnatcatcher (Polioptila califomica californica) and black-shouldered kite (Elanus caeruleus). Woodrat (Neotoma sp.) middens were detected on-site. It is very possible that these middens belong to the San Diego desert woodrat (Neotoma lepida intermedia), which is a federal Category 2 candidate species. Without a small mammal trapping effort the species cannot be determined. During a previous (1994) survey which partially covered the current survey area, a Cooper's hawk (Accipter cooperi) was flushed from a roost on the slope below the condominiums. Other sensitive species with a high likelihood to occur in natural habitats on-site include the silvery legless lizard (Anniella pulchra pulchra) and orange-throated whiptail (Cnemidophorus hyperythrus beldingi). The willow riparian area at the north end of the property was evaluated for least Bell's vireo (Vireo bellii pusillus) in 1994. The habitat is considered to have a low to moderate likelihood for least Bell's vireo presence. The federal and state listed southwestern E I I I i [ [ [ willow flycatcher (Empidonax traillii extimus) is considered to have a low likelihood of occurrence in the willow riparian area. Coastal California Gnatcatcher This species was detected on-site during each of the three directed surveys. During the February 3 survey, two to three gnatcatchers were observed on the coastal sage scrub- covered slope leading up to Paseo del Norte. It was not clear whether the two southernmost observations were of the same animal; hence, the uncertainty as to whether two or three birds were observed. The behavior of the northernmost of the three gnatcatchers was very aggressive, suggesting it was a male defending a territory. The second survey (February 10), revealed two gnatcatchers, both of which were being shy and quiet They were observed only for a moment (despite patient efforts to catch further sight of them), and so sex could not be determined. They were located on the coastal sage scrub-covered slope just east (downhill) from the trailer storage lot along Paseo del Norte. The third (February 17) survey again noted two gnatcatchers on the same slope as the preceding two weeks. One of these was heard calling from the general vicinity of a patch of willows within the channel bottom. Again, the gnatcatchers were very quiet and hard to observe, responding only briefly and irregularly to taped vocalizations. All of the above observations of the coastal California gnatcatcher occurred within the proposed Alignment D, approximately near the middle where it crosses the small canyon. The coastal sage scrub habitat crossed by Alignments A and B has the potential to support coastal California gnatcatcher. 2. Plants Three sensitive plant species were observed during the surveys: wart-stemmed ceanothus (Ceanothus verrucosus), ashy spike-moss (Selaginella cinerascens), and western dichondra (Dichondra occidentalis). The wart-stemmed ceanothus, also known as white coast ceanothus, is a federal Category 2 candidate species. The other two plant species are on the California Native Plant Society's List 4, a watch list of plants of limited distribution. Locations of the white coast ceanothus and western dichondra are shown on Figure 3; the ashy spike-moss occurs on the soil surface between shrubs throughout the area mapped as southern mixed chaparral. Appropriate habitat also occurs within the coastal sage scrub and chaparral on-site for Harpagonella palmeri, but this species was not observed. No sensitive plant species were observed within the proposed alternative sewer alignments. 3. Habitats *** The Diegan coastal sage scrub found in the vicinity of the proposed alternative sewer alignments is considered sensitive by the resources agencies due to its cumulative loss of *"* acreage in southern California over the last two decades and the fact that this community — type often supports sensitive plant and animal species. Coastal California gnatcatchers m occur in the coastal sage scrub habitat on the east- and west-facing slopes of the north- south canyon (see Figure 3). It is assumed that at least one pair of gnatcatchers lives in *"• the canyon, but as many as two pairs may exist in this area. Any action which would «* impact this bird species or its habitat would require consultation with the U.S. Fish and Wildlife Service (USFWS) through either Section 7 or Section lOa of the federal Endangered Species Act UK p« Riparian and wetland areas are considered sensitive due to the cumulative losses of these to habitat types statewide. Section 404 of the Clean Water Act regulates the deposition of fill material being placed in "waters of the U.S." and adjacent wetlands, and these f» regulations are under the jurisdiction of the U.S. Army Corps of Engineers (USAGE). i"* The USAGE issues permits that enable projects to impact wetlands provided every effort has been made to avoid the impacts and to develop mitigation so that there is a no net F loss of wetland acreage or values. Wetland areas of this project are primarily associated with the distribution of southern willow scrub. Unvegetated portions of the main C drainage course of the canyon are considered non-wetland jurisdictional waters due to the presence of a definitive ordinary high water mark. f The California Department of Fish and Game (CDFG) also has jurisdiction over ^* streambeds and issues streambed alteration agreements under Sections 1600-1603 of the Fish and Game Code. CDFG also has a policy of no net loss of wetlands.c c 4. Other Sensitive Areas Steep slopes within the coastal zone which support native vegetation are typically off- limits to development. Exemptions may exist in local coastal zone plans that would permit sewer lines to cross these areas provided measures are taken to offset the impacts to the native habitat Both the coastal sage scrub and southern mixed chaparral on the steep slopes in the vicinity of the project would be included in this category. Alignments A and B would involve traversing steep slopes.E r_ Impact Analysis The following section describes the potential impacts to biological resources for each of the three proposed sewer alignments. A summary of the impacts is given in Table 1. c E 0 E C E- E c E TABLE 1 SUMMARY OF IMPACTS (acres) Habitat Type Alignment A Alignment B Alignment D Coastal sage scrub 0.01 0.35 0.46 Southern willow scrub 0.05 0.29 0.17 Baccharis scrub 0.36 Pampas grass 0.37 0.19 0.22 : i C E 1 E c c S C A. Habitat Alignment A would impact 0.01 acre of coastal sage scrub, 0.37 acre of pampas grass, and 0.05 acre of southern willow scrub with the remainder of the alignment crossing disturbed areas (e.g., agriculture fields). Alignment B would impact 0.35 acre of coastal sage scrub, 0.29 acre of southern willow scrub, and 0.19 acre of pampas grass with the remainder of the alignment crossing disturbed areas (e.g., agriculture fields). Alignment D would impact 0.46 acre of coastal sage scrub, 0.36 acre of baccharis scrub, 0.17 acre of southern willow scrub, and 0.22 acre of pampas grass with the remainder of the alignment crossing disturbed areas (e.g., abandoned agricultural fields). B. Sensitive Species All three alignments would have direct impacts on the coastal California gnatcatcher through the loss of coastal sage scrub habitat Potential impacts to coastal sage scrub habitat on Alignment A could be avoided. Losses of coastal sage scrub habitat could also have direct impacts on potentially occurring species such as San Diego desert woodrat, silvery legless lizard, and orange-throated whiptail. No sensitive plant species that occur on the site would be impacted by the proposed sewer alignments. C. Jurisdictional Waters and Wetlands All of the proposed sewer alignments would cross Encinas Creek. The willow woodland habitat growing along the creek is a wetland based on the presence of hydrophytic vegetation, hydric soils, and the proper hydrology. In addition, Alignment D crosses the drainage in the small north-south canyon. These areas fall under the jurisdiction of both the USAGE and CDFG. Alignment A would impact 0.05 acre of wetland, Alignment B would impact 0.29 acre of wetland, and Alignment D would impact 0.17 acre of wetland. D. Steep Slopes Both Alignments A and B would traverse steep slopes vegetated with native plant species within the coastal zone. Alignment A would temporarily impact 0.17 acre of steep slope and Alignment B would temporarily impact 0.34 acre of steep slope. 11 y y Recommendations G C C E C C - C C The suggestions below are designed to avoid and/or minimize potential impacts to biological resources. Mitigation measures are given for unavoidable impacts to biological resources. A. Avoidance and Minimization Adjustment to the proposed sewer alignments would help avoid and/or minimize impacts to sensitive biological resources. The central sections of Alignments A and B could be adjusted to avoid impacts to coastal sage scrub near the north boundary of Poinsettia Park. Impacts to willow woodland and wetlands along Alignment B could be minimized by rerouting the alignment around the base of the hill to the northeast across disturbed areas and then north across the pampas grass area, similar to Alignment A in this location. Impacts to both coastal sage scrub and wetlands could be minimized along Alignment D north of Poinsettia Park by moving the entire segment of the alignment to the east side of the drainage, out of coastal sage scrub habitat and into baccharis scrub habitat In addition, further impacts to coastal sage scrub can be avoided by moving the east-west segment of the central portion of the alignment south out of the coastal sage scrub habitat Provided that these realignments are made, impacts to willow woodland and wetlands could be further minimized along Alignment D by routing the pipeline around the woodland as suggested for Alignment B above. B. Mitigation Unavoidable impacts to sensitive biological resources will require mitigation. Therefore, any residual impacts to southern willow scrub and coastal sage scrub must be compensated for to reduce the impacts below a level of significance. Impacts to southern willow scrub (includes wetlands) are typically mitigated by the creation and restoration of similar habitat, usually at a ratio of 3:1 (three acres created for each acre impacted). This type of compensation will satisfy the regulatory requirements of the USAGE (404 permit) and CDFG (1603 streambed alteration agreement) likely to be applicable to this project Thus, based on the impact analysis presented in Table 1, the mitigation acreage needed for southern willow scrub habitat would be: Alignment A 0.15 acre Alignment B 0.87 acre Alignment C 0.51 acre Suitable sites for the southern willow scrub restoration exist in the small tributary canyon and along Encinas Creek to the north. Although reviewed on a case-by-case basis by the 12 resource agencies, it is sometimes possible to receive partial mitigation credit for the ** enhancement of riparian habitat through the removal of non-native species, such as P- pampas grass, as long as there is a no net loss of wetland. Whether habitat is created and y restored or enhanced, a mitigation plan will need to be prepared that addresses the site preparation, plant installation, maintenance, and monitoring of the mitigation effort f •* Options for the mitigation of unavoidable impacts to coastal sage scrub habitat involve the restoration of coastal sage scrub habitat at a ratio of at least 2:1 or through the federal F 4d rule process being implemented for this habitat type with respect to the coastal California gnatcatcher. Under the habitat restoration option, a suitable mitigation site E would need to be identified and then restored by planting native coastal sage scrub species. This option would require a mitigation plan to be prepared, as described above. Under the 4d rule option, the City of Carlsbad must submit the proper findings to the P USFWS that allows them to credit the incidental take to their approved coastal sage scrub • take allowance. The 4d rule findings would contain the mitigation requirements of the project which typically involve either conservation of unprotected coastal sage scrub L habitat off-site or habitat restoration. Regardless of which mitigation option is chosen, final approval of the mitigation must come from the USFWS in order to comply with the C federal Endangered Species Act. Consultation with the USFWS may be initiated under Section 7 (if coupled with the 404 permit), under Section lOa, or through the 4d rule process. . C C C C c i c C References California, State of 1994 Natural Diversity Data Base. Natural Heritage Division, Department of Fish and Game. Data base search current through January 1994. Holland, Robert F. 1986 Preliminary Descriptions of the Terrestrial Natural Communities of California. Nongame-Heritage Program, California Department of Fish and Game. October. Skinner, Mark, and Bruce Pavlik 1994 Inventory of Rare and Endangered Plants of California. California Native Plant Society Special Publication No. 1,5th ed. Sacramento. In press. 13 L o c . ATTACHMENTS L C L G C D L G G e c ATTACHMENT 1 C C i C G ATTACHMENT 1 PLANT SPECIES OBSERVED Scientific Name Common Name Origin Acacia sp. Adenostomafasciculatum Hook. & Arn. Ambrosia psilostachya DC. Artemisia californica Less. Arundo donax L. Atriplex semibaccata R.Br. Avena barbata Link Baccharis pilularis DC. Baccharis salicifolia (Ruiz Lopez & Pav(5n) Pers. Brassica sp. Bromus diandrus Roth. Carpobrotus edulis (L.) Bolus. Ceanothus verrucosus Nutt. Centaurea melitensis L. Chenopodium ambrosioides L. Conium maculatum L. Conyza canadensis (L.) Cronq. Cortaderia selloana (Schultes) Asch. & Graebner Dichelostemma capitatum Alph. Wood Dichondra occidentalis House Encelia californica Nutt. Eriodictyon crassifolium Benth. Eriogonumfasciculatum Benth. vai.fasciculatum Erodium cicutarium (L.) L. Her. Eucalyptus spp. Focniculum vulgare Mill. Gnaphalium canescens DC. ssp. beneolens (Davidson) Stebb. & Keil. Hemizoniafasciculata (DC.) Torrey & A. Gray Heteromeles arbutifolia (Lindley) Roemer Heterotheca grandiflora Nutt. Isocoma menziesii (Hook. & Arn.) G. Nesom var. menziesii Isomeris arborea Nutt. Lactuca serriola L. Leymus condensatus (C. Presl) A. Love Limonium perezii (Stapf) Hubb. Lofttf scoparius (Nutt in Torrey & A. Gray) Ottley var. scoparius Acacia Chamise Western ragweed California sagebrush Giant reed Australian saltbush Slender wild oat Coyote bush Mule fat, seep-willow Mustard Ripgut grass Hottentot fig Wart-stemmed ceanothus Tocolote, star-thistle Mexican tea Poison hemlock Horseweed Selloa pampas grass Blue dicks Western dichondra Common encelia Felt-leaved yerba santa California buckwheat White-stemmed filaree Eucalyptus Fennel Fragrant everlasting Golden tarplant Toyon, Christmas berry Telegraph weed Coast goldenbush Bladderpod Prickly lettuce Giant ryegrass Perez rosemary California broom I N N N I I I N N N N I N N N N N I I I N N N N N N I N I N en ATTACHMENT 1 PLANT SPECffiS OBSERVED (continued) Scientific Name Common Name Origin Lupinus bicolor Lindl. Malacot hamnus fasciculatus (Torrey & A. Gray) E. Greene Malosma laurina (Nutt.) Abrams Malva parviflora L. Marah macrocarpus (E. Greene) E. Greene Mimulus aurantiacus Curtis Myoporum laetum Forst. Nassella pulchra (A. Hitchc.) Barkworth Nerium oleander L. Nicotiana glauca Grab. Opuntiaficus-indica (L.) Miller Opuntia littoralis (Engelm.) Cockerel!. Oxalis pes-caprae L. Poa annua L. Raphanus sativus L. /?/»w integrifolia (Nutt.) Brewer & Watson Ricinus communis L. Rumex crispus L. Salix laevigata Bebb Salsola tragus L. Salvia mellifera E. Greene Sambucus mexicana C. Presl Sonchus oleraceus L. Tamarix sp. Xanthium strumarium Xylococcus bicolor Nutt. schidigera K.E. Ortgies Miniature lupine Chaparral mallow Laurel sumac Cheeseweed, little mallow Wild cucumber Bush monkeyflower Myoporum Purple needlegrass Oleander Tree tobacco Indian fig Shore cactus Bermuda buttercup Annual bluegrass Radish Lemonadeberry Castor bean Curly dock Red willow Russian thistle, tumbleweed Black sage Blue elderberry Common sow thistle Tamarisk Dwarf nettle Cocklebur Mission manzanita Mohave yucca N N N I N N I N N N N 1 N N I I I N N N OTHER TERMS N = Native to locality I = Introduced species from outside locality c E L D 0 m E ATTACHMENT 2 1 C ra ATTACHMENT 2 WILDLIFE SPECIES OBSERVED/DETECTED ON THE POINSETTIA PARK SEWER SITE Common Name Scientific Name Occupied Habitat Status Evidence of Occurrence Amphibians California toad Birds Black-shouldered kite Northern harrier Red-shouldered hawk Red-tailed hawk California quail Mourning dove Greater roadrunner Anna's hummingbird Black pboebe Scrub jay Common raven Bushtit Bewick's wren Northern mockingbird Wrentit Coastal California gnatcatcher House finch Yellow-rumped warbler Rufous-sided towhee California towbee Song sparrow Western meadowlark Red-winged blackbird Bufo boreas halophilus Elanus caeruleus Circus cyaneus hudsonius Buteo lineatus elegans Buteo jamaicensis Callipepla californica californica Zenaida macroura marginella Geococcyx californianus Calypte anna Sayomis nigricans semiatra Aphelocoma coerulescens obscura Corvus corax clarionensis Psaltriparus minimus minimus Thyromanes bewickii Afimus polyglottos polyglottos Chamaea fasciata henshawi Polioptila californica californica Carpodacus mexicanus frontalis Dendroica coronata Pipilo erythropthalmus megalonyx Pipilo crissalis Melospiza melodia Sturnella neglecta Agelaius phoeniceus O CFP.SDC,* CSC.SDC CMC CSS.O.F SWS CSS SWS CMC.CSS F CSS CSS All CSS CSS CSS,CMC,Ag CSS CMC CSS CSS G,Ag SWS SDC FT,CSC,SDC O O V,0 O.V O O 0,V O O O V.O Ov,o Oo,v O O V v,o v,o V O f"!n ATTACHMENT 2 WILDLIFE SPECIES OBSERVED/DETECTED ON THE POINSETTIA PARK SEWER SITE (continued) Common Name Scientific Name Occupied Habitat Status Evidence of Occurrence Mammals Opossum Raccoon Coyote California ground squirrel Woodrat Introduced Species Domestic cat Domestic dog Didelphis virginiana Procyon lotor Canis latrans Spermophilus beecheyi Neotoma spp. Felis domesticus Canis familiaris SWS SWS CSS CSS SWS SWS All T T T,S 0,T D T T Habitats Ag CMC CSS F G O SWS SM Agriculture Coastal mixed chaparral, mixed chaparral, chamise chaparral Coastal sage scrub, inland sage scrub Flying overhead Grassland, pasturelands, etc. Open places, waste places, roadsides, burns, etc. Southern willow scrub Saltwater marsh Status CFP CSC FT SDC Evidence of Occurrence V = Vocalization O = Observed T = Track S = Scat D = Den site C = Carcass/remains California fully protected species California Department of Fish and Game species of special concern Listed as threatened by the federal government City of San Diego Resource Protection Ordinance "Sensitive Species" Taxa listed with an asterisk fall into one or more of the following categories: • Taxa considered endangered or rare under Section 15380(d) of CEQA guidelines • Taxa that are biologically rare, very restricted in distribution, or declining throughout their range • Population(s) in California that may be peripheral to the major portion of a taxon's range, but which are threatened with extirpation within California • Taxa closely associated with a habitat that is declining in California at an alarming rate (e.g., wetlands, riparian, old growth forests, desert aquatic systems, native grasslands)