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HomeMy WebLinkAboutCT 13-03; Robertson Ranch West Village; PLANNING AREA 1 SOIL FILL-EROSION CONTROL REVEGETATION PROGRAM; 2016-07-19-------1 PLANNING AREA 1 SOIL FILL EROSION CONTROL REVEGETATION PROGRAM ROBERTSON RANCH WEST VILLAGE JUN 0 8 2016 LAN MENT G Prepared for: TOLL BROTHERS INC. 725 Town & Country Road Suite 200 Orange, CA 92868 Prepare by: PLANNING SYSTEMS 1530 Faraday Ave. Suite 100 Carlsbad, CA 92008 May 19, 2016 PLANNING AREA 1 SOIL FILL EROSION CONTROL REVEGETATION PROGRAM ROBERTSON RANCH WEST VILLAGE May 19,2016 1.0 BACKGROUND This program is called the Planning Area 1 Soil Fill Erosion Control Revegetation Program ("Program"). This Program involves the installation of an erosion control revegetation project over approximately 3.25 acres of a deposited permanent soil embankment in Planning Area 1 in the western comer of the Robertson Ranch West Village (see Figure 1 -Location Map). The soil fill revegetation site is located within Hardline Open Space currently supporting weedy, non-native fallow agricultural land. The proposed project involves the import of soil onto the 3.25 acre site and revegetation of the site with Diegan Coastal Sage Scrub ("DCSS") vegetation. This Program describes the design, installation, maintenance, and monitoring work required of the Property Owner ("Toll Brothers Inc") to establish the revegetation. This Program describes the methodologies for creating an erosion control planting ofDCSS habitat similar to the biological character of other naturally occurring DCSS habitat in the area on Robertson Ranch. It includes a planting design, installation methodology, a maintenance program, monitoring procedures, success criteria, and ultimately a tum-over process to the Long Term Conservancy Manager ("CNLM"). The term anticipated for achieving tum-over ready DCSS revegetation is three years. 2.0 PROJECT RESPONSIBILITY All activities indicated in this revegetation Program are the responsibility of Toll Brothers Inc, including the installation, establishment, maintenance and monitoring of the created DCSS for the period until success criteria is met. Restoration Specialist. Supervision of the installation, maintenance, and monitoring of this restoration project will be the responsibility of a restoration specialist ("RS "), hired by Toll Brothers Inc. The RS will directly overseeing the planting, seeding, weeding, and maintenance. The RS will provide regular monitoring reports that include lists of items in need of attention. If remediation is needed the RS will propose work needed to establish revegetation that is likely to meet success criteria. The restoration specialist will prepare and provide annual reports to Toll Brothers Inc and CNLM. Contractors will install and maintain the revegetation under direction of the RS and in accordance with this Program. Installation Contractor. The installation contractor work includes: site preparation, soil preparation, irrigation installation, container planting, hydroseeding, erosion control, and weed control. He will also be responsible for all project maintenance during the 120-day establishment phase. Maintenance Contractor. All maintenance following the initial establishment period will be performed by a maintenance contractor. A minimum of two years and eight months of maintenance is required for this project. Maintenance will include but not be limited to weed control, trash removal, watering, fence repair, dead plant replacement, and re-seeding. All maintenance activities conducted will be seasonally appropriate and considerate of the bird nesting season, and approved by the RS. Figure 1 Location Map PA 1 -Soil Stockpile Revegetation Area Carlsbad, California EB NORTH 0 125 250 500 1000 ~I I SCALE: 1" = 500' IT~~Ei':~ I I •II February 12, 2016 ~&sW~ctt~#E[~ING POUCY .AND PROCESSING ENVIRONYENTAL W'l'JGATION 1530 FARADAY AVENUE. SUITE 100. CARlSBAD, CA ('760) 931-0780 F.AX (760) 93J-l'i744 EROSION CONTROL REVEGETATION PROGRAM WEST VILLAGE PLANNING AREA 1 SOIL FILL Conservancy [Long Term] Manager. Upon acceptance of the revegetation, responsibility for permanent long term management of the revegetation areas will be transferred to CNLM, to manage the revegetated land in an environmentally and biologically beneficial manner as per the management of the adjacent natural habitat, in accordance with the requirements of the Robertson Ranch Open Space Land Management Plan Addendum (Planning Systems 2014) and consistent with state and federal environmental laws. 3.0 RESTORATION INSTALLATION Implementation of this Program is expected to begin as soon as feasible upon completion of soil import to final grade of the fill. Upon achieving fmal grade as shown in Figure 2; Grading Exhibit, the perimeter of the revegetation area will be fenced in order to secure the area from outside interference. Then in sequence: temporary irrigation installation, container planting, erosion control, and hydroseeding will be performed. The entire restoration planting is anticipated to be complete within 4 weeks of initiation ofthe effort. The restoration area is shown on Figure 3; Future Biological Resources. The steps associated with initial revegetation ofthe site are indicated in the following sections. 3.1 Fencing of Revegetation Area Limits Permanent fencing of the Tamarack Avenue frontage at the northern property line with 3-strand wire fencing shall be installed. In addition, temporary, orange environmental fencing shall be erected to clearly demarcate the perimeter of the work zone. 3.2 Site Preparation Soil samples shall be collected by the RS and submitted to a soils testing lab. A complete analysis of each sample with recommendations will be provided to the RS. Particular attention shall be paid to pesticides and herbicides and other hazardous materials. Soil amendments are expected to be necessary. The RS will determine the fmal soil amendment schedule. 3.3 Erosion Control Temporary silt fencing protection shall be installed along the perimeter of the revegetation plot. Straw wattles will be utilized horizontally on the soil slopes to hold soil from eroding. If hay or gravel bales are indicated for the revegetation area on the engineer's plans, these features shall be installed. A cover crop applied via hydroseed will assist erosion control during the initial establishment period. 3.4 Irrigation Installation An above-grade irrigation system with an automatic controller shall be installed to irrigate the revegetation area. The installation contractor shall provide irrigation scheduling and adjustment throughout the entire 120-day initial installation. At the time that the revegetation has matured to the level that the RS determines that the revegetation can sustain without irrigation, it shall be discontinued. The target date for cessation of irrigation is two years after the date that the installation was deemed complete. If the plantings require additional water, irrigation shall continue on those areas, for as long as necessary to achieve proper establishment. Upon completion of the monitoring phase of the project, above-grade components of the irrigation system will be removed from the plots. Erosion Control Revegetation Program May 19,2016 3 83 NORTH Q 25 SQ 10o·0······2QQ ~·-' I Figure 2 SCALE: 1" = 100' Grading Exhibit PA 1 -Soil Stockpile Revegetation Area February 12, 2016 '•II Carlsbad, California 11~30 FARADAY AVENUE, SUITE 100, CARLSBAD, CA 92006 (760) 931-07EIO FAX (760) 931-5'1'44 LEGEND CJ EXTENSIVE AGRICULTURE [II! NON-NATIVE VEGETATION I. ·!I SOUTHERN WILLOW SCRUB lfl{~l DEVELOPED (FUTURE) !:;; 'j COASTAL VALLEY FRESHWATER MARSH f> ,.J COASTAL SAGE SCRUB- REVEGETATED ~ SOUTHERN WILLOW SCRUB- REVEGETATED 1. O'day Consultants -Grading Exhibit (November 13, 2015) 2. Merkel & Associates-'Biological Resources Report' (October 5, 2004) 3. Glen Lukes Assoc. -Updated biology for Drainage 'A' vicinity (2011) 4. Planning Systems-'Rancho Costera DCSS Revegetation Plan' (August 6, 2014) Figure 3 Future Biological Resources PA 1 -Soil Stockpile Revegetation Area Carlsbad, California EE 25 50 100 NORTH SCALE: 1" = 100' February 12, 2016 1530 FARADAY AVENUE, SUITE 100, CARLSBAD, CA (760} 931-0760 FAX (760) 931-5744 EROSION CONTROL REVEGETATION PROGRAM WEST VILLAGE PLANNING AREA 1 SOIL FILL 3.5 Container Planting The approved container planting palette (plant species, size and number/acre) specified in Table 1. Container plants shall be planted prior to hydroseeding. Table 1· DCSS Container Plant List Qty. Qty.per .I<. LaiinName . ··:: Common Name Siie Spacing (3.25 i l2700sf I .... acres)·.· ........ •·· cell • .. . 312 6 Artemesia californica Coastal sagebrush 1 gal 10ft. 208 4 California encelia Califomica encelia 1 gal 10ft. 208 4 Erio;;onum fasciculatum Flat-top buckwheat 1 gal 10ft. 208 4 Malosma laurina Laurel sumac 1 gal 10ft. 208 4 Rhus inte;;ri(olia Lemonade berry 1 gal 10ft. 312 6 Salvia mell!fera Black sage 1 gal 10ft. 1,456 28 TOTAL 3.6 Hydroseed Installation Hydroseeding will follow container planting. The approved seed mix (plant species and pounds/acre) are shown on Table 2. Hydroseeding shall consist of a hydraulic application of a DCSS native seed mix plus a slurry mixture of water, seed, fertilizer, organic soil stabilizer and mulch (Hydroseed Slurry #1, below). All will be applied in a one-step application. 2 0.10 3 1.0 Encelia califomica 4 0.75 Erio onum fasciculatum var. fasciculatum 5 0.25 Deinandra fasciculata 6 1.0 Eschscholzia califomica 7 0.15 8 1.0 9 3.0 10 0.75 11 6.0 Hydroseed Slurry #1 Irrigated Coastal Sage Scrub (3.25 acres total) gtv. 2000 lbs/ac 700 lbs/ac 300 lbs/ ac 150 lbs/ac 30 lbs/ac description cellulose fiber Hydro-post compost (available from S&S seeds) 6-2-4 Tri-C humate fertilizer Guar gum soil stabilizer Mycorrhizal inoculum Erosion Control Revegetation Program May 19,2016 Coast California buckwheat 6 '' 3. 7 Offsite Domestic Plantings EROSION CONTROL REVEGETATION PROGRAM WEST VILLAGE PLANNING AREA 1 SOIL FILL An approximate 30-foot wide section of City of Carlsbad ROW exists directly adjacent to Tamarack Avenue. This area is presently vegetated with domestic plantings, (typically acacia and eucalyptus). Areas of this ROW that are disturbed by the soil transport effort, including sidewalk, irrigation lines and domestic vegetation, shall be replaced by Toll Brothers Inc. as follows: • Curb, gutter and sidewall< shall be repaired as necessary to City standards; • Irrigation lines shall be repaired or replaced as necessary (domestic planting shall be placed on separate meter and lines from DCSS revegetation); • Street trees shall be installed at 40-foot intervals within 10-feet of back of sidewalk; and • DCSS container planting and hydroseeding per Sections 3.5 and 3.6 above shall be installed within the remaining ROW beyond the 10-foot back of sidewalk location. 4.0 MAINTENANCE The revegetation site shall be maintained regularly in order to achieve optimum growth. Maintenance activities are indicated in the following sections. Toll Brothers Inc. shall be responsible for three (3) years of maintenance in accordance with this Program. 4.1 Weed Control Weeds that occur within the revegetation area will be targets for removal. All weeds listed by the California Invasive Plant Council on List A-1 and List A-2 (www.cal-ipc.org) shall be aggressively targeted for immediate removal when identified. Less threatening weeds will be controlled as time and resources dictate, with the intent of removing all non-native species from the revegetation. All methods of weed removal must be approved by the RS prior to being implemented by the contractor. The goal of the revegetation project is to establish native habitat that is essentially weed-free. 4.2 Erosion Control Repair of erosion rills on slopes is the contractor's responsibility. The contractor shall repair small erosion problems as noticed, and not to allow them to become major problems. Erosion control devices such as decomposed straw wattles shall be replaced as necessary. The contractor shall make irrigation system repairs as needed. 4.3 Fertilizer Fertilize will be applied only if directed by the RS. 4.4 Replacement of Vegetation If it is determined that plants have died and remedial plantings are necessary, the RS shall provide a written description of the necessary work to Toll Brothers Inc and the contractor. Re-hydroseeding shall occur iflarge areas do not support seedlings (hand seeding may be allowed for small areas). Container plants which are dead or unhealthy shall be replaced according to the adopted success criteria. Replacement of missing or poorly performing plants will occur as directed by the RS. Erosion Control Revegetation Program May 19,2016 7 EROSION CONTROL REVEGETATION PROGRAM WEST VILLAGE PLANNING AREA 1 SOIL FILL 5.0 MONITORING The RS will monitoring the project from the first day of installation until the project is accepted by CNLM. The monitoring term will be three years assuming the success criteria has been met. 5.1 Installation Monitoring The RS will monitor habitat restoration installation activities, including site preparation and installation of irrigation, plant, and seed material. Specifically, the RS will ensure the irrigation system is installed correctly, monitor the installation of plants and seed material, conduct an installation walk and prepare a punch list(s) as necessary to insure a complete, healthy installation, and prepare a letter for Toll Brothers Inc and the contractor stating that the installation is complete and the maintenance and monitoring period has begun. 5.2 Maintenance Monitoring Following installation, the RS will monitor maintenance activities conducted by the maintenance crews during the 32 month (3 years minus 120 day installation) maintenance and monitoring period. During each monitoring visit, the RS will inspect the restoration area to ensure that the restoration effort is progressing as planned and to identify any problems that may affect the effort. Monitoring memos regarding plant establishment, irrigation, sediment control, etc. will be provided following each inspection to the contractor and to Toll Brothers Inc. The contractor will be responsible for repairs within their contracted scope of work. 5.3 Performance Monitoring Performance monitoring is targeted to grow DCSS revegetation that complies with success criteria. This monitoring shall also begin once the 120-day establishment period is complete. Monitoring shall occur once every three months. Monitoring Notes will be provided to the contractor and to Toll Brothers Inc to document every scheduled monitoring visit. In order to adequately evaluate ongoing success, quantitative data will be collected at the Year 2 and Year 3 anniversaries. California Native Plant Society data sampling protocols will be employed to generate this data. Two hundred meters of randomly-selected line intercept transects will be measured and located on a map each reporting year. This data will then be averaged to provide a composite sample that will be compared to the success criteria. If the revegetated habitat does not meet success criteria for that year, remedial measures shall be recommended to Toll Brothers Inc, and implemented during the next growing season. Sampling will provide data on vegetative cover of CSS species, percent cover of non-native species, and% bare soil. Consistent sampling techniques will be used throughout the monitoring process to ensure accurate comparisons. Results will be included in reports submitted to Toll Brothers Inc and to CNLM. 6.0 SUCCESS CRITERIA The following success criteria (Table 3) will be used to assess whether the revegetation has established satisfactorily, and is ready for long-term management. Three years of success criteria for DCSS revegetation areas shall comply with the following success criteria: Erosion Control Revegetation Program May 19,2016 8 EROSION CONTROL REVEGETATION PROGRAM WEST VILLAGE PLANNING AREA 1 SOIL FILL Table 3: Success Criteria 120Da 100% survival of contractor installed container material. list Year 85% survival of installed container material, unless their function and value has been replaced by same species seed or natural recruitment 15% achievement absolute vegetative cover of native species No Cal-IPC weeds present J 2nd Year 30% achievement of absolute vegetative cover of native sQ_ecies No Cal-IPC weeds present Annual exotics shall not exceed 25% of measurable cover I 3ro Year 50% achievement of absolute vegetative cover of native species No Cal-IPC weeds present Annual exotics shall not exceed 20% of measurable cover By year-end, permanently discontinue irrigation, unless remediation is required. 6.1 Final Performance Monitoring Final performance monitoring of the revegetation shall take place no sooner than three years after the installation was installed. When the RS has determined that the revegetation has satisfied the Year 3 success criteria, the RS shall document the findings in a Final Report. 7.0 PROJECT ACCEPTANCE The Final Report will be distributed to the Toll Brothers Inc and CNLM. Representatives of the two parties will visit the site to confirm that all project criteria have been met. After visiting the revegetation, CNLM shall notify the Toll Brothers Inc of acceptance ofthe revegetation, or detail issues that CNLM believes should be resolved prior to taking over management of the site. If the site is acceptable to both parties the Toll Brothers Inc shall authorize CNLM to begin all future management activities of the revegetation. Erosion Control Revegetation Program May 19,2016 9