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Home My WebLink About3338; Agua Hedionda & Calavera Creek Dredging; University Office & Medical Park - San Marcos; 2009-12-30UNIVERSITY OFFICE AND MEDICAL PARK AMENDMENT TO SP 90-24 (UOMP) PROJECT CITY OF SAN MARCOS, CALIPORNIA CONCEPTUAL COMPENSATORY WETLAND MITIGATION AND MOMTORING PLAN - OFTWI'E ELEMENT December 30,2009 Revised March 12,2010 Prepared for: H.G. Fenton Company Contact: Allen Jones 7577 Mission Valley Rod, Suite 200 San Diego, CA 92 108 Prepared by: Merkei & Associates, Inc. Contact: Amancla K. Gomales 5434 Ruffin Road San Diego, California 92 123 Phone: (858) 56@5465 Fax: (858) 560-7779 Errnail; a~omk~e1imcgm KQ*+ Amanda K. Gonzales, f&d~iolo~ist ~eith#w. Merkel, Principal Consultant VOW Project . &ncepual Coyatoty Wetlund Mtigucion arsd Mitoring Pkan . Offsih? Element Revised Md 12. 2010 TABLE OF CONTENTS .... ................... ...... PROJECT INFORMATION ............................................... , , , ..., , ...,.. 1 TmmG ....................................................................................................................................................................... 3 JURISDICTIONAL AREAS TO BE IMPACTED ................................................................................................................. 4 TYPES, FUNCTIONS, AND VALUES OF lHE JURISDICTIONAL AREAS TO BE DIRE~LY AND INDIWC~~Y MA- ... 6 Summaty of hrisdictiomal Arms ........................................................................................................................... 6 Exbting Ftinctions and Values ......................... .... ........................................................................................... 7 H+f qy ................ ... .................................................................................................................................... -8 DESCRIPTION OF THE PROPOSED COMPENSATORY MlTIGATION SITF, a ..... a .................... , ... 9 SELE~ON PRm s .............................................................................................................................................. 9 STATEMENT OF NEEDBITE SEL~~ APPROPRMTENESS ........................................................................................ 9 Sm LOCATION MD SIZE ....................................................................................................................................... -10 OWNERSHIP STATUS ............ .. ............................................................................................................................... 1 WETLAND DELINEATION .......................................................................................................................................... 1 EMSTING CONDITIONS ............................................................................................................................................ 11 Regional Conm~ ............................................................................................................................................. 11 ihd Context ...................................................................................................................................................... -12 Wetland Functions rmd Valua ........................................................................................................................... 15 PRESENT AND PROPOSED US~S OF THE COMPENSATORY MITIGATION S~E AND hL ~ER ADJACENT AREAS .... 17 REFERENCE Sm ........................................................................................................... .. .... .. .............................. 17 Sm P~omro~ INSTRUMENT ............................................................................................................................... 18 GOALS OF THE C0MPE:NSATORY MITIGATION ......................... ,. ........................... ....-...- ..... 19 TW'@S] AND AREA@) OF WITAT TO BE PRESERVED. RESTORED. ESTABLISHED AND/OR ENHANCED .................. 19 Creation ............................................................................................................................................................... 19 Enkrmcment ....................................................................................................................................................... 20 TIME LAPSE BETWEEN JURISDIF1'IONAL IMPACE AWD EXPUTFED CO~MPENSAW~Y M~GATION SUCCESS............^^ E~T~MATED COST ..................................................................................................................................................... 24 ADDITIONAL AREAS PROPOSED AS COMPENSATORY MITIGATION ......... ... .......................................................... 2 OVERALL WATERSHED IMPROVE ME^ TO BE GAINED ......................................................................................... 24 IMPLEMENTATION PLAN FOR THE COMPENSATORY MITIGATION SlTE. ............................ 35 RATIONALE POR EXPECTING IMPLEMENTATION SUCCESS ........................................................................................ 25 RESPONSIBLE PARTIES ............................................................................................................................................ 25 FINANCIAL A~SWNCES ....................................................................................................................................... 25 SCHEDULE .............................................................................................................................................................. -26 SITE PREPARATION ................................................................................................................................................... 26 Stakhg ad FIagsing ........ ... ......................................................................................................................... 26 Trash rmvaUIYed Eradication ....................................................................................................................... -27 Grading Piun ......... .... ................................................................................................................................. -27 Soil Preparatim .............................................................................................................................................. -27 Gmnd Water Monitoriffg ................................................................................................................................... 28 H+IO&Y Monito- ................... .. ................................................................................................................ -28 Sire Access and Sf aging ........................................... ...., ....................................................................................... 28 PLANTING SPECIFICATIONS ..................................................................................................................................... -28 IRRIGATION PLAN .................................................................................................................................................... -28 PLANTING PLAN ....................................................................................................................................................... 28 M&I & Associates. I nc. #02#1-I5 i UOW Project . Conceptual Conrgematory Wetland Mtigafion and Wnidaring Plm . wife Elemf Revised firth 12.2010 ........ MANENANCE ACTIWTiES DURING THE MONITORING PERIOD. ....,...-.......- ..-. 30 RESPONS~BLE PAR= ............................................................................................................................................. 30 Applicmi ........................... ...... ............................................................................................................................. 30 hcomfmn 4eciaiisi .......................................................................................................................................... 30 Rmegeralion Cmtmctor ...................................................................................................................................... 30 Seed Sources ....................................................................................................................................................... .30 MAINTENANCE A~ITIES .................................... ........................................................................................... 31 Site Pmtection . Fencing/Signage ...... .... .................................................................................................... -31 Tmsk arrd Deb* Removal ................................................................................................................................ 31 Wd Contml .................................................................................................................................................... 31 Horficsrltural Tmahmh .................................................................................................................................... -32 Erosion Cml ................................................................................................................................................. 32 RepIacmmt Plm fings ...................................................................................................................................... 32 Planting ............................................................................................................................................................ 32 Hydroseed ........................................................................................................................................................ 32 Zmgafiiora Mkinfemce ....................................................................................................................................... 32 Pest hagement ................................................................................................................................................ 33 SCHEDULE ................................................................................................................................................................ 33 ..... MONITORING PLAN FOR THE COMPENSATORY MITIGATION SITE .... - ..-..--.- - ..-. 35 Mo~rrom~ METHODS AND SUCCESS ~ERIA .................................................................................................... 35 Qwiilative Sumqs .................... ... ................................................................................................................ 35 Qwniilative Surveys .......................... .. ............................................................................................................ 35 CaIifwnia Rapid hsment Method (CRAM) .............................................................................................. 35 Vegetation Monitoring ..................................................................................................................................... 39 Photo Documentolion .......................................................................................................................................... 40 Soil Mnirhg .................................................................................................................................................... 41 Creation Site .................................................................................................................................................... 41 Enhancement Site .................................... .... ................................................................................................... -41 &.$ace H+lo@ Mhnitoring ............................................................................................................................ 42 Creation Site .................................................................................................................................................... 42 Enhancement Site ............................................................................................................................................ 43 MONITOIUNG SCHEDULE ........................................................................................................................................ 43 PERFORMANCE STANDARDS FOR TARGET DATES AND SUEESS CRITERIA .............................................................. 43 ANNUAL MONIMRING REPORTS .............................................................................................................................. 43 ............ COMPLETION OF COMPENSATORY MITIGATION ..., ...... , ..., ..... ......,...- ....... ...- -.44 CONTINGENCY MEASURES . ....,...,...,.... .................... .... ,....,. ....................... -45 INITIATMG PROCEDURES ............................................................................................................... .. ................ 45 ALTERNATIVE LOCATIONS FOR CONTINGEISCY COMPENSATORY MITIGATION ........................................................ 45 RE~WNSIBLE PARTIES ..................................................................................................................................... -45 Table 1 . Impacts to Jurisdictional Wdimds and Non-Wetland Resources .................................................................. 5 ......................... Table 2 . Summary DistriMon of Impacts to Jurisdictional Wetlands and Non-Wetland Resources 5 Table 3 . Distribution of Mitigation to Jurisdictional Wethds and Non-Wetland Resources .................................... 19 UOMP Project - Conceptual Compensatory Wetlarrd Mtigdion and llBoni~oring Plan - mite Element Revised &rch 12,2010 PROJECT INFORMATION This Conceptual Compensatory Wetland Mitigation and Monitoring PIan (Plan) is provided as a requirement of federal and state wetlaud permit/agrmnent applications to offset and evaluate compensation for unavoidable impacts associated with the implementation of the University Office and Medical Park Amendment to SP 90-24 (UOMP) Project. Applications for a Clean Water Act (CWA), Section 404 Individual Pennit (SPL-20064I2063), CWA, Section 401 (File No. 07C409; WPN: 18-2007009: MPORT), and a California Department of Fish and Game (CDFG), Section 1602 Sheambed Alteration Agreement (CDFG File #1600-2007-0070-R5) have been submitted and are currently being processed. This Plan has been prepared in acc&ce. with the U.S. Army Corps of Engineers' (ACOE) 2004 Final Mitigutwn Guidelines and Mimitoring Requireme&. On and ofiite compensatory mitigation will be required as a result of the UOMP Project. This Plan documents the offiite compensatory mitigation and discusses the following: 1) description of the project impacts, 2) goals of the compensatory mitigation project, 3) description of the compensatory mitigation site, 4) implementation plan for the compensatory mitigation site, 5) maintenance activities during the monitoring period, 6) monitoring plan for the compensatory mitigation, 7) completion of compensatory mitigation, and 8) contingency measures. A separate Plan documenting the onsite compensatory mitigation has been prepared by M&A (March 10,20 10). H.G. Fenton Company 7577 Mission Valley Road Suite 20Q San Diego, CA 92108 Phone: (6 19) 400-0134 Fax: (619)400-0111 Contact: W. Allen Jones Email: allen~fentan.corq Merkel & Associates, Inc. (M&A) 5434 Ruffin Road Sau Diego, CA 92 123 Phone: (358) 560-5465 Fa: (858) 560-7776 Contact: hh. Amad Go& or Mr. Keith Merhl E-mail: ~es@makeli11~,txim: hndcel@!~~~.~ The proposed UOMP Project is located within unsectioned lands west of Section 14, Township 12 South, Range 3 West of the San Bernardino Base and Meridian 7.5 minute San Marcos Quadrangle (htitude 33.13074" N, Longitude 1 17.175 1 So W) (Figure 1). Lacally, the site is located south of State Route 78, east of Bent Avenue, north of Craven Road, and west of Twin Oaks Valley Road in the City of San Marcos. University Office and Medical Park Amendment to SP 90-24 Project Conceptual Wetland Miation and Monitoring Plan - Offsite Element 1 :42000 Source: USGS 7.5 San Mams and San turn Rey, CAQuadrangtes UOW Project - Concqtud Cumpemfoty Wetland Mitigation and llfonitoring Plan - mite Ekm~ Revised Mzrch 12,2010 H.G. Fenton Company (Applicant) has proposed development of the approximate 10hre UOMP Project, which would include: 1) public inbsbucture improvements as called for in the City of San Marcos (City) General Plan pursuant to the City Circulation Element; 2) medical and professional ofiice uses consistent with the City General Plan, which may include a hospital and supporting retail uses; and 3) preservation and restoration of the San Mms Creek Open Space corridor through the site. The project Applicant has designed the UOMP Project hm the Approved Scripps Specific Plan (SP) to maximally avoid wetlands along the San Marcos Creek corridor, including the incorporation of sidcant realignment of Discovq Street and full bridging of the creek by Grand Avenue to minimize wetland impacts, wh1e still providmg for these required Circulation Element roadways. Specifically, the Approved Scripps SP located Discovery Street along the northern bouudary of the property through San Macros Creek and the entire property would have been developed under the Approved Scripps SP. The proposed UOMP Project has realigned Discovery Street to the maximum extent practical to minimize wetland impacts along the project's northern boundary such that the alignment would occur fiilly within the office and medical park site to the south of San Marcos Creek. The realignment includes design variances on curve radii as well as reduction of travel lanes and inclusion of non-standard intersections. The inclusion of these change has been to reduce impacts to the maximum extent possible while achieving a safe design. Project irnpacts have further been reduced along the project's northern boundary as the Applicant is replacing the previously proposed level spreaders with a Filterra system as the Best Management Practice (BMP) for b&g storm water runoff. The City of San Marcos had initially requested that the project use level spreaders; however, to further reduce impacts to jwidctiond resources to the maximum extent practicable, the Applicant will use a Filterra system. The use of this system would be just as effective as Ievel spreaders and will not affect the development potential of lots located north of Discovery Street. Any further modification of the Tentative Subdivision Map (TSM) in this area to avoid impacts to wetlands (i-e., requiring steepened slopes and/or construction of walls) would reduce the usable areas of lots and substantially affect the viability of the project. Details regarding avoidance of wetlands has been discussed extensively within the Envimnmmfal hject Agency (EPA) section 4040(I) PracticabIe Aifernafives Analysis (M&A March 2008) and the Adendurn to EPA 's section 408@)(1) Practicable Alternatives Analysis (MU July 2009). On November 30,2009, the Corps determined the project, as modified, to be the Least Environmentally Damaging Practicable Alternative (LEDPA) under section 404(b)(l) of the EPA Guidehes. The proposed SP includes two development zones: 1) Medical mce/HospitayProfessional Oflice/Support Retail Planning Area, which may incIude medical offices, a hospital, professionaI offices, and supporting retail uses and 2) Habitat Preserve Planning Area, a designated open space of 15.5 acres for the protection of San Marcos Creek. TIMING Initial construction on the UOMP Project is anticipated to begin upw approval of the project and receipt of all applicable project permits. Removal of vegetation is expected to occur over a perid of two weeks. Inhstructure and completion of building pads is expected to extend for approximately 15 to 18 months; construction of buildings on finished pads is dependent on market demand and will UOMP Projecl - Conceptual Compensatory Wetland Mifigation and Mmitoring Phn - msiie Element Revised March 12,2010 extend beyond that time and =cur throughout all seasons of the year. A11 site activity is expected to occur during daylight hours as required per the City ordinance. The public infrastructure improvements and medical and office park private development, collectively, would result in permanent and temporary impacts to 7.2 acres of waters of the U.S. under the CWA $404 jurisdiction of the ACOE. Table 1 documents the impacts as a result of the proposed project and Table 2 provides a summary distribution of impacts to jurisdictional wetlands and non-wetland resources. Project impacts to jurisdictional resources would result primarily from construction of Discovery Street and Grand Avenue and secondarily from the office park private development. As documented within Table 1, more than half the total permanent impacts would occur within low quality wetlands supporting low physical, chemical, and biobgical function. The low quality wetlands consist of herbaceous wetland, eucalyptus woodland-wetland, aikali meadow, and non-wetland waters U.S./stmmbed, all of which exhibit minimal biological value due to lack of native floristic diversity, a well-developed canopy stratum, or dense understory. Further, much of the affected wetlands are inundated only during infiquent storm events with dmnage occurring rapidly following the passing of the storm. While Discovery Street has been significantly realigned to the south to avoid impacts to the Creek, it cannot avoid permanent and temporary impacts to riparian forest and scrub habitats or low growing marsh communities. Permanent impacts include complete development of the road while temporary impacts are those impacts that are required for the initial construction of the road and will ultimately be restored in place. Much of the permanent impacts are to lower quality wetlands within the southwestern portion of the site where a low-lying mesic field comprised predominantly of disturbed herbaceous wetland and linear bands of coastal and valley freshwater marsh exists. Dominant flora within the vicinity include the non-native bristly ox-tongue (Picris echioih), a facultative plant (FAC) that is defined as having a similar likelihood of occurring in both wetlands and non-wetlands (estimated probability of occurrence in a wetland is 33% to 67%). The completion of Grand Avenue as a bridge across San Marcos Creek t~ Discovery Street will resuit in permanent and temporary direct impacts to riparian forest, scrub, and marsh communities as a result of the following: I) bridge supports, 2) impacts of the bridge span itself, and 3) temporary construction impacts. It should be noted that the shaded areas beneath the proposed bridge have been treated as permanent impacts even though these areas will not be filled. This has been treated as such as it is expected that the bridge may have a shading effect on the-vegetation directly under and in proximity to the span (east to west); which primarily consists of low-growing herbaceous vegetation between the forest canopy. At this location, a utility road has been maintained for access to power poles and Iines. Much of the remaining permanent impacts would occur on the south side of the bridge where a mature stand of eucalyptus woodland-wetland will be removed. Temporary impacts will be incurred during the construction of the bridge. These are expected to result primarily in impacts to forest habitat via tramplinglcrushing of vegetation while accessing the river bottom to construct bridge falsework and to construct bridge piers. All temporary impacts would be restored in place. Merkel dc Associates, Inc. #02-041-15 4