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HomeMy WebLinkAboutCT 02-14; Bressi Ranch Residential; Tentative Map (CT) (31)ft 100 La Mesa Blvd., Suite 150 La Mesa, CA 91941-6476 e-mail: admin@helixepi.com fax (610) 462-0552 phone (619) 462-1515 RECEIVED 0£C 0 9 2002 December 6, 2002 LEN-16 Ms. Kristine Zortman Lennar Homes of California 5780 Fleet Street, Suite 320 Carlsbad, California 92009 Subject: Bressi Ranch On-site Coastal Sage Scrub Mitigation Dear Ms. Zortman: This letter provides the specifications for on-site coastal sage scrub mitigation at Bressi Ranch. This mitigation consists of salvaging the topsoil and shrub canopy from coastal sage scrub habitat in development areas and redistributing it in currently disturbed areas outside the project development footprint. Bressi Ranch is located at the southeast corner of Palomar Airport Road and El Camino Real in Carlsbad, California (Figures 1 and 2). Farming has disturbed most of the ranch, although isolated stands of native and naturalized vegetation remain. Responsible Parties. Four entities will be necessary to complete this project, including the project proponent, restoration biologist, grading contractor, and landscape contractor. The project proponent, Lennar Homes of California, is responsible for underwriting the mitigation program. The restoration biologist is responsible for marking collection areas, overseeing the collection, site preparation and reapplication in the mitigation areas, and the two-year maintenance program. The grading contractor, who must be properly licensed and bonded, will collect and redistribute the soil and vegetation. The landscape contractor shall maintain the site in a weed-free state for two years. Neither of the contractors nor the restoration biologist has been selected. Schedule. Site preparation, vegetation and soil salvage and reapplication of salvaged is best done in the late summer or fall, during which time soil salvage and redistribution is best done because soil microorganisms are dormant and less subject to destruction while being relocated. This work may be done during other seasons, but it will not be as effective. Site Preparation. The soil salvage deposition or mitigation areas should marked by a licensed land surveyor. Edges of the mitigation area adjacent to native habitat shall be enclosed by a four-foot tall orange plastic construction fence to prevent unauthorized impacts. Any unnatural land forms (e.g., berms and eroded gullies) should be recontoured to the satisfaction of the restorarion biologist. Letter to Ms. Kristine Zortman December 6, 2002 2 of 2 Salvage. A licensed land surveyor will mark the impact footprint through the existing stands of coastal sage scrub, of which there are approximately 31 acres available for salvage. Edges of the salvage areas adjacent to native habitat shall be enclosed by a four-foot tall orange plastic construction fence to prevent unauthorized impacts. The edges of the salvage areas adjacent to disturbed habitat will be marked with stakes to ensure the collection of sage scrub soils only. Next is the vegetation salvage and coarse mulching. The contractor can elect to do this by one of two methods: scraping the vegetation up and processing it through a mulcher, or crushing it in place by driving over it with a bulldozer and then scraping it up. The mulch should be set aside, after which time the top six inches of soil will be collected. Reapplication. The salvaged soil should be applied directly to the mitigation area. If storage is necessary, please contact me for storage specifications. Salvaged soils shall be spread over the mitigation area at a depth of six inches. The topsoil will then be ripped to a depth of 10 inches, which is a depth necessary to integrate the salvaged soils into the mitigation site's surface. Following distribution and ripping, the soil will be consolidated by track walking. After consolidation, the vegetation mulch will be spread uniformly over the site. Finally, standard erosion control measures (e.g., straw wattles, gravel bags, and hay bales) shall be installed where necessary to minimize erosion until the vegetation becomes established. Two-year Maintenance Period. The mitigation areas will be weeded six times over the next two growing seasons. The tentative schedule for weeding is March, May, and June. The actual timing of the weeding will be determined by the rainfall pattern and subsequent plant growth in those years, as determined by the restoration specialist. Although these specifications call for 31 acres of soil salvage and reapplication, the on-site mitigation requirement is only 25 acres. Thus, the two-year weeding program will be required only for the 25 acres shown on Figure 3. If you have any questions concerning this project, please call Barry Jones or me. W. Larry Sxvafd Senior Biologist Enclosures: Figure 1 - Vicinity Map Figure 2 — Location Map Figure 3 - Coastal Sage Scrub Salvage and Mitigation Areas ORANGE I SAN DIEGO SM^CT^ UNITED STATES.— VI JSIDRO 7^^ MEXICO DEUX Regional Location Map BRESSI RANCH Figure 1 Optional Off-site Improvement Area" Scale: 1" = 2000' Source: USGS 7.5 min Quadrangles; San Luis Rey, San Marcos, Encinitas, Rancho Santa Fe HELIX Project Vicinity BRESSI RANCH Figure 2 LEGEND Coastal Sage Scrub Preserve Areas d_J) Coastal Sage Scrub Salvage Areas Coastal Sage Scrub Restoration Areas On-site Coastal Sage Scrub Mitigation Area Other On-site Vegetation Indicates Area of Project Impacts N 600 600 Job No: LEN-16 Date: 12/6/02 1200 Feet Note: This map is based on site conditions as observed at the time of our field investigations. The information presented herein was developed by visual inspection and/or aerial photograph interpretation. Note that both site conditions and applicable regulatory requirements may change. HELIX Coastal Sage Scrub Mitigation Areas BRESSI RANCH Figure 3