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HomeMy WebLinkAbout; Carlsbad Golf Course Wetlands Mitigation Plan; Composite Wetlands Mitrigation Plan Golf Course; 2000-05-01Exhibit A I I CARLSBAD GOLF COURSE COMPOSITE WETLANDS MITIGATION PLAN Prepared for: ' cny OF CARLSBAD ' 1635 Faraday Avenue Carlsbad, Califorma 92008 Contact: John Cahill Telephone: 760-602.-2926 ' Prepared by:. P&D ENVIRONITIENTAL SERVICES 401 West "A" Street, Suite 2500 San Diego, CaUfomia 92101 Contact: Betty Dehoney Telephone: 619-232-4466 May 2000 City of Carlsbad Golf Course Riparian Mitigation Plan TABLE OF CONTENTS Section Page LO ' • GOLF COURSE RIPARIAN MITIGATION PLAN (dated February 2000) 1 1.1 Project Description 1 1.2 Existing Conditions 3 1.3 Impacts ; 5 1.4 Revegetation Mitigation 7 1.5 Methodology '. 8 1.6 Supplemental Mitigation Measures 14 . 1.6.1 Cowbird Trapping 14 1.6.2 Exotic Removal ; : 14 2.0 ADDENDUM I: SUPPLEMENTAL TO CARLSBAD GOLF RIPARIAN MITIGATION PLAN : 15 3.0 ADDENDUM IL CARLTAS ENHANCEMENT SITE 23 List of Figures 1 ' Regional and Vicinity map. 7 Existing Habitats .; 4 3 Riparian Mitigation Area 6 4 Boundary for Enhancement Property : 26 List of Tables 1 Wetland Impact and Mitigation Requirements 7 2 Plant Species Recommended for Carlsbad Golf Mitigation Site ;.10 3 Project Success Standards and Measures to be Taken if the Standard is Not Met : : .....13 4 Wetland Impact and Mitigation Requirements (Modified March 2000) 18 5 Plant Species Recommended for Carlsbad Golf Mitigation Site (Modified March 2000) .19 6 Project Success Standards and Measures to be Taken if the Standard is Not Met (Modified March 2000) 21 0 P&D Environmental Page City of Carlsbad Golf Course Riparian Mitigation Plan 1.1 PROJECT DESCRIPTION In 1989, Carlsbad .voters approved a 2 percent increase in Transient Occupancy Taxes through Proposition M for the acquisition of land and the construction of an 18-hole golf course. The golf course -was identified as a priority for utilization of the recreation funds derived from Proposition M.- In addition to the 18-hole championship golf course, the proposed project includes a clubhouse, maintenance facility, driving range, conference center, and pads for industrial/golf related uses. An outdoor police shooting range will be relocated from its location in the northeastern portion of the site to a location in the western portion of the site. The 418-acre site is located in the northwestern,quadrant of the City of Carlsbad. Palomar Airport Road forms the southern boundary of the site, Hidden Valley Road forms the eastern boundary, and the southern edge of grading for the future extension of Faraday Avenue forms the northern boundary (Figure 1). Prior to purchasing and designing the proiect, the City conducted a biological reconnaissance and initiated consultation with the U.S. Fish and.Wildlife Service (USFWS) and the California Department of Fish and Game (CDFG) to determine the feasibility of constructing a golf course on the project site. Indications from the USFWS were that the project appeared to be feasible. Subsequently, the engineering design program incorporated information from numerous biological focused surveys, which included sensitive habitat, animal, and plant species locations, in designing the course. To reduce the significant impacts to biological resources, this mitigation plan is proposed. The mitigation plan has been designed in consultation with the USFWS. and CDFG. From the outset this course was designed to minimize impacts to the sensitive resources on the project site. Prior to any public presentation of this design many initial design features or course modifications were incorporated to reduce or eliminate impacts to known sensitive resources. The following measures were taken to reduce impacts to sensitive biological resources prior to, and during the golf course design process: • Identified the agency preferred wildlife corridors. • Agencies requested. 600-foot wide corridor in the north and 800-foot wide corridor in the south. The project was designed to preserve as much native habitat as possible in these areas. Areas within the corridors that required temporary disturbance or were occupied by non-native will be revegetated with coastal sage scrub. " Extensive gnatcatcher surveys were conducted over multiple years. P&D Environmental Pagel T-y- ^ P&D Environmental Services Vicinity Map Source: USGS Map Figure 1 City of Carlsbad Golf Course Riparian Mitigation Plan • Staked and surveyed riparian corridor and designed the project to minimize impacts to the corridor. • • Conducted engmeers on reconnaissance to facilitate design that impacted non-native and disturbed habitats first and reduced impacts to sensitive resources.. " Riparian cart crossing to hole 13 minimized to reduce impacts to Cannon Road riparian mitigation area. • Fairway rough on hole 2 reduced in width to increase native vegetation and corridor width following revegetation. • Fairway rough on hole 2 reduced in width to increase native vegetation and corridor width following revegetation. • Fairway rough on hole 11 reduced in width to increase native vegetation and corridor width following revegetation. • Fairway on hole -13 pulled back to widen buffer around. Cannon Road riparian mitigation area. • Riparian cart crossing utilized existing agricultural access road. • Firing range rotated and redesigned to widen preserved corridor. • Industrial pad redesign to reduce impact and tncrease corridor width following revegetation. • Eliminated third tee on hole 5 to increase corndor width at crossing of College Avenue. • Moved cart path around green 15 to avoid gnatcatcher site no. 11. 1.2 EXISTING CONDITIONS There are five principal habitats located within the project site; in some cases, these habitats can be further broken down into distinct forms , of the primary habitats. Historically, the site has been used for agricultural purposes and the habitats are generaliy in various successional stages. Native habitats are interspersed in non-native grasslands resulting in a mosaic pattern on the site. Figure 2 illustrates the existing habitats on the project site. There are 80.2 acres of coastal sage scmb habitat present on the site. The functions and values of the coastal sage scrub within the impact area vary greatly. The habitat ranges P&D Environmental Page 3 I I I I City of Carlsbad Golf Course Riparian Mitigation Plan from a high quality, floristically diverse, native habitat to a lower quality, less diverse habitat with an abundance of non-native weedy species. The sensitive wildlife species present in fhe coastal sage scrub include the California gnatcatcher, orange-throated whiptail, and California mfous-crowned sparrow. Southern mixed chaparral occupies 4.99 acres of the proposed project site. The habitat present on the project, site is quite limited in extent and diversity. The chaparral is dominated by chamise, which is the most common indicator of chaparral habitats throughout the state. The area that will be impacted by the proposed project does not support a diverse assemblage of species normally indicative of southern mixed or southern maritime chaparral. Southern maritime chaparral is also located • on the project site (1.77 acres); however, the project has been designed to avoid this sensitive resource and it has been incorporated into a wildlife corridor. Grasslands occupy 201 acres of the project site including both non-native grass and native components. The grasslands present are'dominated by non-native species including slender wild oat, ripgut brome, soft chess, red brome, perennial ryegrass, and foxtail fescue. The native grasses are represented by small-flowered needlegrass and purple needlegrass with several other species having very limited distributions on the site. There are approximately 2 acres of native grassland found on the site which are well integrated into the non-native grasslands and do not function as a separate habitat, Disturbed areas including fallow and actively used agricultural lands and other unnatural vegetation types occupy 104.95 acres of the site. These areas range from having no native habitat to being dominated by non-native ruderal species with some recmitment of native • species. The areas designated as disturbed or agricultural have little or no habitat value for •native wildlife. . Wetlands and riparian habitats are limited to the streamcourse found on the project site. Riparian woodlands dominate the riparian habitats with willow species being the most abundant trees species. Some minor pockets of riparian scmb are located in isolated canyons on the site. In a few areas where water collects and ponds, emergent riparian species occur, including cattails, mshes, and sedges. In total, wetland habitats occupy .30 acres of the project site. 1.3 IMPACTS • The total grading footprint of the project on the wetland habitats consists of 3.65 acres of wetland and riparian habitats. Figure 3 illustrates the impacts. anH wetland mitigation for the proposed project. m • . • P&D Environmental Page 5 City of Carlsbad Golf Course Riparian Mitigation Plan 1.4 REVEGETATION MITIGATION Mitigation for "Waters of the U.S.," wetland, and riparian impacts is proposed. This report will discuss wetland and riparian habitat mitigation measures and the critical elements of the riparian mitigation plan. The wetland mitigation plan shown on Table 1 will be based upon the following ratios: Table 1 "Wetland" Habitat Impacted R.uio Miti<jacion Southern Willow Scmb " 1.30 3:1 3.90 Mule Fat Scrub •97 3:1 "5.91 Freshwater Marsh .22 1:1 .22 Riparian Herb .16 ; 1:1 .16 Non-Wetland Waters .10 i' 1:1 .10 Total 3.75 10.29 I I The wetland restoration project will be located- within the channel of a' natural streamcourse and will have sufficient year-round water to establish and support a willow woodland. The project will rely on this natural water source to sustain the riparian plant community. The mitigation area will encompass an area of 4.5 acres as shown in Figure 3. This project specifies the use of riparian plant species that were successfully used in, the Cannon Road Mitigation Program. The riparian habitat restoration location will be protected from unauthorized entry. The wetland mitigation area is within the golf course and will be adjacent to areas of play. The wetland will be clearly marked as an "out of bounds" zone. The margins of the wetlands will be planted with species that discourage intmsion such as wild rose, blackberry, and southwestern spiny msh. Barrier fencing wili be used in key areas to discourage unauthorized entry. Frequently, a combination of measures is required to adequately protect the riparian habitat. Regular monitoring until the plants are established will allow early detection of areas of poor gro-wth or cover, dying plantings, weed invasion, and erosion problem.."?. These problems can then be addressed and appropriate corrective actions taken. The monitoring will be performed in conjunction with a long-term maintenance program. Several additional management program factors will improve the habitat value of the . restored riparian habitats, including a cowbird trapping program, education program identifying the sensitive resources, and light control. P&D Environmental Page 7 City of Carlsbad ' Golf Course Riparian Mitigation Plan One of the most- important threats to native songbirds, especially those that nest in riparian woodlands, is nest parasitism by the brown-headed cowbird. A requirement of the golf course operation will be a permanent cowbird trapping program, and will be implemented to ensure increased songbird nesting success in the restored and preserved riparian woodlands. - An educational program will be designed to inform the golfers of the presence and importance ofthe sensitive resources on the project site. Signage for those sensitive areas where ingress needs to be restricted will be identified. The on-site restored and preserved riparian habitat could • be affeaed by the additional lighting if precautionary measures are not ta:ken. These measures include shielding light sources so that light is not directed toward the riparian habitat and directing all high- intensity lighting away from the riparian habitat. These measures are incorporated into the design and overall management program for the Golf Course. Off-site mitigation will include enhancement and/or restoration of resources. Potential areas for enhancement or restoration of 5.8 acres (10.29 - 4.5 = 5.79 acres) includes one or a combination of sites: Encinas Creek adjacent to Palomar Airport Road (pampas grass removal program), enhancement and creation at Lake Calaveras, enhancement at Agua Hedionda Lagoon, or other sites found suitable by the resource agencies. 1.5 METHODOLOGY There are seven primary requirements for the success of a habitat restoration effort: 1. Select an appropriate location for the restoration effort , • 2. • Removal of non-native mderal species that- compete with desired species. 3. Soil preparation, including topsoil importation and/or mycorrhizal fungi inoculation if necessary. • ' 4. Seeding or planting with appropriate plant species for the location and microclimate. . • • 5. Protect the site from further disturbance. . 6. • Monitor success and make changes to the-program if necessary. 7. Maintain the site during the plant establishment period. This may include weeding, trash removal, irrigation and. barrier repair. P&D Environmental • Page 8 City of Carlsbad Golf Course Riparian Mitigation Plan Riparian Mitigation Program The 4.5-acre wetland mitigation site is located along the north and south banks of the creek. One of the sites is adjacent to the Cannon Road riparian mitigation site and existing Macario Creek riparian corridor. Figure 3 illustrates the location of the proposed riparian mitigation sites. - The mitigation plan consists of creating a diverse willow riparian woodland and scmb habitat. An understory component will'also be included within the willow woodland and scmb habitat area. The understory will increase the diversity and function of the habitat, especially during the woodland establishment period. The proposed planting plan has three basic components: 1) the planting of overstory container stock; 2) an understory container stock; and 3) then hydroseeding an herbaceous understory seed mix (Table 2). Overstory Container Stock The overstory component will include black, arroyo, and sandbar willows; Fremont cottonwood; western sycamore; and mulefat. Plant material will be purchased from reputable nurseries specializing in native species. All sites will require excavation to provide correct hydrologic functioning. Southern willow scmb will be planted where the depth to groundwater does not exceed 6 feet. Plantiiig should be conducted after October 1 to reduce hot weather stress. Container trees and shmbs will be planted using standard horticultural practices: excavating a planting hole twice the diameter of the root ball, filling the hole twice with water, and leaving the plant crown approximately 1-inch above grade after planting. Plants • will be placed in soils that have been thoroughly watered before planting, and watered immediately after planting. Any roots wrapped around the root ball will be loosened. The plants should be planted in clusters of three to five simulating natural patterns. The monitoring biologist will be present onsite during the planting and seeding procedures on an as-needed basis. The monitoring biologist should conduct a final check of the site after the planting is complete.' The final check will document that plants were appropriately placed by the contractor, and the correct species have been used. P&D Environmental : ' , Page 9 City of Cdrlsbad Golf Course Riparian Mitigation Plan Table 2 Plant Species Recommended for Carlsbad Golf Mitigation Site Cont.iiner No. per Acre or '>v:icntific Name Common Name . Size Lbs. per Acre Willow Riparian Woodland Overstory Container Plants • Salix goodingii Black Willow 1 gallon 250 . Salix lasiolepis Arroyo Willow 1 gallon 250 Populus fremontii Fremont Cottonwood 1 gallon 16 Plantanus racemosa Western sycamore 5 gallon 16 Baccharis salicifolia Mulefat 1 gallon 335 Salix exigua Sandbar willow Igallon 335 Understory Container Plants Rosa califomica Wild rose 1 gallon 30 Sambucus mexicana Mexican elderberry 1 gallon 50 Vitis girdiana Wild grape 1 gallon 10 Rubus ursinus California blackberry 1 gallon 30 Ribes indecorum Winter current 1 gallon 30 funcus acutus Spiny msh 1 gallon 30 Understory Hydroseed Anemopsis califomica Yerba mansa 2 lbs* • Artemisia douglasiana Mugwort 2 lbs Artemisia dracunculus Tarragon . 2 lbs -. Cotula coronopifolia Brass Buttons lib Melilotus officinalis Yellow s-weet clover 4 lbs Pluchea odorata Marsh fleabane 2 lbs Solidago califomica California goldenrod 2 lbs Festuca megalura Foxtail fescue 3 lbs Notes: ''•Pounds per acre shouid be confirmed with the native seed nursery. Pounds may vary based on viability of that particular crop. Understory Container Plantings Wild rose, Mexican elderberry, wild grape, California blackberry, winter current, and spring msh will be planted in container stock. These species will be planted in clusters -to simulate natural conditions. Wild rose, California blackberry, and spring msh will be used along the perimeter of the mitigation site (between the native revegetation sites and active -use areas) to discourage unauthorized ingress into the mitigation site. Planting methodology will follow standard horticultural protocol pertaining to hole size, watering, and refilling. P&D Environmental Page 10 City of Carlsbad . Golf Course Riparian Mitigation Plan Seed Mix The seed mix includes the same species as identified in the Conceptual Mitigation Plan for Reaches 1 and 2 of Cannon Road (Table 2), This mix utilizes the most common plants found on the site that are commercially available. The seeds for this mix-are generally available at several native seed suppliers in California. Following weed removal, alteration of site topography, and installation of container plantings and cuttings, the site'will be hydroseeded. The hydroseed mix will include the designated seed mix and a light mulch. The hydroseed mix should be spread over the site to conceal the seed from predators, protect it from wind and rain erosion, and help retain moisture. The mulch should be made of 93 percent wood cellulose/fiber matrix with 7 percent organic soil stabilizer. Irrigation Plan Temporary irrigation will be provided to insure plant establishment. Watering will be provided during the dry season for the firsf two years of the plant establishment period. Following the second winter season the watering schedule will be gradually reduced to allow the plants to acclimate to the natural seasonal water supply. Monitoring A vital component of any revegetation program developed to .mitigate habitat loss is documentation of the progress of the revegetation program until the plants are established. . Monitoring will be performed in conjunction with a long-term maintenance program. General observations will be important in documenting areas of poor gro-wth or cover, dying plantings, weed invasion, and erosion problems. These areas can then be independently rnonitored and scheduled for more intensive maintenance activities. If necessary, the areas may be replanted or reseeded. The monitoring program will use a variety of qualitative and quantitative procedures to document the changes in plant gro-wth of the target species and changes in the density and dominance of all plant and wildlife species within the sampled areas. One of the most important procedures wili be standardized observation • of the , entire site to provide a general record of trends on the mitigation site including plant gro-wth. Potential coverage may include photographic documentation from designated points which would give a visual record of the changes in stmcture and cover of the sites oyer time. •. Quantitative studies would be conducted to obtain plant cover estimates, seedling counts, and monitor changes in plant diversity on-site.. fA P&D Environmental Page 11 City of Carlsbad Golf Course Riparian Mitigation Plan Performance Criteria There are generally two types of performance criteria used to monitor the success of a revegetation effort; measurements of survival rates and measurements of vegetation coverage. Which of these criteria is appropriate depends on several factors, including the goals and objectives ofthe project, the time frame of the monitoring effort, and the types of habitat being established. For the Carlsbad Golf Course mitigation project, determination of vegetative cover is the appropriate measure of project success. In the willow woodland/riparian scmb areas, measurements of vegetative cover are the appropriate yardstick by which success will be determined. This is because these areas are expected to quickly develop dense coverage of riparian habitats. The types of vegetation planted will include an understory seed mix and dense riparian overstory, as well as the specified container plantings. The project success standards and measures to be taken should the standards not be met are presented in Table 3. Quantitative Monitoring The line-intercept sampling method will be used to determine the amount of cover achieved. To measure coverage by the line intercept method a transect (line) is established between two points. A tape measure is then stmng between the two points and the length of intersection that each species has with the line is measured. When the coverage of all species is totaled the result is frequently greater than the length of the transect because many species have overlapping areas of coverage. By measuring the area of bare ground intersection the total vegetative cover can be established. Five, 50-foot transects will be established in the 4.5-acre revegetation area. If qualitative observation indicates that plant establishment is relatively homogenous on the site, the number of transects can be reduced to a number that accurately reflects the conditions on the site. The number of transects required will be determined by the monitoring biologist, but in no case shall be less than three transects dispersed approximately evenly across the site. Qualitative Monitoring The entire site will be visually inspected and qualitative or subjective determinations about the success of the revegetation will be made. This is necessary because the quantitative sample sites might not include important data. p&D Environmental Page 12 City of Carlsbad Golf Course Riparian Mitigation Plan Tables Project Success Standards and Measures to be Taken if the Standard is Not Met Standard Measure if Standard Not Mot 70% groundcover (visual estimate based on hydroseed development. Reseed/replant Establishment of all species planted • Reseed/replant. Substitutions possible 80% healthy container tree plantings Replace with same species/size 80% survival of tree plantings' Replant 80% survival of remaining shrub plantings' .-Replant Height standards met for all trees Replant or receive remedial measures, substitutions possible Tree Height Standards^ Cottonwoods 10 feet Sycamore . . : • • - 9 feet Willows . .11 feet Mulefat, sandbar willow, elderberry 6 feet 95% survival of tree plantings' Replant 80% survival of shrub plantings' Replant 80% groundcover by all species Additional seed or container plantings as recommended by revegetation. designer Canopy cover standards met for trees and shmbs •Replant or receive remedial measures, substitutions possible • Canopy Cover Standards^ Willow riparian woodland 80% Brackish marsh , ,. 80% Notes: 'Dead container plants can be mitigated for by naturally invading seedlings. ^Mean height, in feet. 'All canopy covers given in percentages. Schedule •Immediately following installation, the site will be monitored monthly for six months to evaluate germination and the initial success of the revegetation effort. If germination is unsuccessful or the seedlings do not survive, a change in scope may be required to determine the cause of failure. For the. 6 to 12-month period, monitoring will be quarterly. If the success criteria are being met at the end of 12 months, from month 12 to the end of the monitoring period, the site will monitored annually. To ensure success of P&D Environmental Page 13 City of Carlsbad ; Golf Course Riparian Mitigation Plan the revegetation program, any areas that require reinstallation of materials will have their monitoring program started over at the time of reinstallation. If, at the end of the third year, the revegetation has met all success cnteria without intervention the previous year, the project will be considered a success and monitoring will be discontinued. Annual Reports Annual reports will be submitted to the City of Carlsbad. The City of Carlsbad will be responsible for submitting, the report to the U.S. Army Corps of Engineers and the CDFG. L6 SUPPLEMENTAL MITIGATION MEASURES In addition to the proposed on-site habitat creation program and off-site mitigation (through enhancement or restoration of 5.8 acres), the project proposes two supplemental mitigation measures: cowbird trapping and exotic removal. 1.6.1 Cowbird Trapping Cowbird trapping is required for 5 years by the USFWS under the Biological Opinion for Cannon Road (USFWS 1992). After the Cannon Road trapping program has been completed, the golf course will continue the trapping program in perpetuity (or under the least Bell's vireo has been removed from the endangered species list). Cowbird traps sholild be set every 100 linear yards along Macario Canyon (five traps total) in the riparian habitat during the least'Bell's vireo breeding season (May through August). The trapping program will be operated to avoid checking the traps on weekends and holidays. Traps would be suppUed' with food, water, and at least one live cowbird to lure others into the trap. At the end of the reason, any live cowbirds would be properly disposed of. Cowbird trapping would occur for the entire monitoring period. All trapping must be conducted by persons holding a live cowbird trapping permit from the USFWS. L6.2 . Exotic Removal Within the boundaries of the golf course, an exotic removal program will be initiated. The exotic primarily targeted for this program is pampas grass [Cortaderia selloana). Surveys of the golf course will be conducted annually and any pampas grass specimens identified will be removed. I fA P&D Environmental Page 14 ./•*-y ADDEIVDUMI SUPPLEMENT TO CARLSBAD GOLF RIPAIOAN MITIGATION PLAN City of Carlsbad • Golf Course Riparian Mitigation Plan Addendum I Supplement to Carlsbad Golf Riparian Mitigation Plan Riparian Buffer A buffer has been created along the perimeter of the streamcourse. The buffer includes two separate planting mixes: playable rough and non-playable rough. The playable rough will contain an open vegetation type, predominantly native grass species. The non- playable rough will support a more dense vegetation and be generally less than three feet in height. A complement of species will be used in each species mix. The following presents a list of species to be used in each buffer. Species for Native Buffer ~ Carlsbad Golf Course USFWS Recommendations, February 12, 2000 Buffer Plant Pallette ("dense vegetation, less than 3 feet in height) "Out of Bound" Adolphia californica (Califomia spinebush)* Anemopsis californica (yerba mansa)* Iva hayesiana (San Diego marsh-elder) Juncus acutus ssp. leopoldii (spiny msh)* Lycium califomicum (Califomia boxthom) Opuntia littoralis (shore cactus)* ^ Opuntia prolifera (cholla)* Rhamnus crocea (spiny redberry)* i?/?^.?/rz7o^?ata (basketbush) j'jjeczoi-wm (fuchsia-flowered gooseberry) Rosa californica (Califomia rose)* Rubus ursinus (Califomia blackberry) Yucca schidigera {MojavQ yuccdL)* Native Rough (open vegetation: playable) Acnatherum coronatum (needlegrass) - Anemopsis californica (yerba mansa)* Bloomeria crocea (San Diego goldmstax)* . , Bothriochloa barbinodis (cane bluestem)* Calochortus splendens (splendid maxiposa lily)* . Cardionema ramossimum (sandmat)* • , Centaurim venustum (canchalagua)* Dichlostemma capitatum iyiildhyacinXh)* • Dichondra occidentalis ('western dichondra)* Distichlis spicata (saltgrass)* Dodecatheon clevelandii (shooting star)* P&D Environmental ' Page 16 I I City of Carlsbad Golf Course Riparian Mitigation Plan Elymus glaucus (blue wild-rye) Hordeum brachyantherum (Califomia barley) Horkelia cuneata (wedgeleaf horkelia) •, Melica frutescens (tall mellic) Me/zca zOTper/ecta (small-flowered mehc grass) Nassella cernua (nodding needlegrass) Nassella lepida (foothill needlegrass)* Nassella puichra (purple needlegrass) Phalaris angusta (timothy) Saliva columbariae (chia)* Selaginella cinerascens (ashy spikemoss)* Sidalcea malvaeflora (checkerbloom)* Sisyrinchium bellum (blue-eyed grass)* * = On-site per Draft Environmental Impact Report The objective of the buffer is to provide a transition from the non-native species mix used on the fairways and "golf rough". The buffer will not need to be irrigated or managed through supplemental application of fertilizer. This transition will reduce the potential of encroachment of species from the manicured golf course to the adjacent riparian habitat. Raven is the proposed site manager and responsible for operations at the golf course. They provide an extensive program of measures to reduce nuisance mnoff using timers and electronic sensors and utilize an integrated pest management system to reduce the application of .pesticides and herbicides. According to data from Cohen et. al (Water Quality Impacts by Golf Course in fournal of Environmental Quality 1999) , effective golf course management reduces the incident of nuisance mnoff contaminated with herbicides, pesticides and fertilizers. However, in the event that there is some transport of materials from the manicured course, this transitional buffer is anticipated to capture this material reducing or eliminating the transport into the streamcourse. A 50 foot buffer has been established from the edge ofthe playable course to the edge ofthe proposed mitigation site. This area will be planted with the non-playable rough species mix and has been designed to capture the first flush runoff of 0.5 inch. Physical barriers (split rail fence, "poison oak" signage and "rattlesnake" signage) will be used to discourage ingress into the sensitive resource areas. Barrier planting (including Califomia rose and Califomia blackberry) will be used in the buffer to further reinforce the out of bounds areas. The locations and types of buffers are depicted in the attached figure. Cross-sections are also provided at 11 locations along the drainage course. The City will also instittite a water quality monitoring program to measure the quality/quantity of mnoff from the manicured course. If the monitoring program identifies P&D Environmental Page 17 City of Carlshad Golf Course Riparian Mitigation Plan contamination from the course entering into the drainage, remedial action will be proposed to reduce the contamination. Mitigation Ratios The impacts associated with the project are presented below. The ratios proposed by the City include 3:1 for southem willow scmb and. mule fat scmb; 2:1 for freshwater marsh and riparian herb; and 1:1 for non-wetland waters. The mitigation plan proposes to replace the impacted wetlands/waters with no net loss of riparian woodland on-site and additional enhancement off-site in the form of pampas grass removal at the Carltas/Palomar Airport Road site. The increase in functions and values associated with the mitigation significantly exceed the functions and values of the impacts. The project proposes a minimum of five acres creation on-site with the remainder of the mitigation credits being obtained through the referenced enhancement (approximately 5.3 acres at Carltas). Table 4 Wetland Impacts and Mitigation : Requirements Hahitut Impact Ratio jVIitigatioh Southern 'Willow Scrub 1.30 3:1 3.90 Mulefat 1.97 3:1, 5.91 Freshwater Marsh • 0.22 2:1* 0.44 Riparian herb 0.16 2:1* , 0:32 Non-wetland waters 0.10 • 1:1 ' O.IO Total 3.75 10.67 "•Modified March 16, 2000 Detailed Planting • • The mitigation plan consists of creating a diverse willow riparian woodland and scmb- habitat. An understory component will also be included within the willow woodland and scmb habitat area. The understory will increase the diversity and function of the habitat, especially during the woodland establishment period.: The proposed planting plan has three basic components: 1) the planting of overstory container stock; 2) an understory container stock; and 3) then hydroseeding a herbaceous understory seed mix (see table on following page). Overstory Container Stock The overstory component will include black, arroyo, and sandbar wilfows; Fremont cottonwood; Westem . sycamore; and mulefat. Plant material will be purchased from reputable nurseries specializing in native species. All sites will require excavation to provide coriect hydrologic functioning. Southem willow P&D Environmental Page 18, City of Carlshad Golf Course Riparian Mitigation Plan scmb will be planted where the depth to groundwater does not exceed 6 feet. Planting should be conducted after October 1 to reduce hot weather stress. Container ttees and shmbs -will be planted using standard horticultural practices: excavating a planting hole twice the diameter of the root ball, filling the hole-twice with water, and leaving the plant crown approximately one-inch above grade after planting. Plants will be placed in soils that have been thoroughly watered before planting, and watered immediately after planting. Any. roofs wrapped around the root ball will be loosened. The plants should be planted in clusters of three to five simulating natural pattems. Tables Plant Species Recommended for Carlsbad Golf Mitigation Site ConUiiiier No. per Acre or .Scientific Name Common Name .Size Lbs. per Acre . Willow Riparian Woodland Overstory Container Plants Salix goodingii Black Willow 1 gallon 250 Salix lasiolepis Arroyo Willow 1 gallon 250 Populus fremontii Fremont Cottonwood 1 gallon 16 Plantanus racemosa Westem sycamore 5 gallon 16 Baccharis salicifolia Mulefat 1 gallon 335 Salix exigua Sandbar willow Igallon 335 Understory Container Plants Rosa califomica Wild rose 1 gallon 30 Sambucus mexicana Mexican elderberry 1 gallon 50 Vitis girdiana • Wild grape 1 gallon 10 Rubus ursinus Califomia blackberry 1 gallon 30 Ribes indecorum Winter current 1 gallon 30 Juncus acutus Spiny msh; 1 gallon 30 Understory Hydroseed Anemopsis californica Yerba mansa 2 lbs* - Artemisia douglasiana Mugwort 2 lbs Artemisia dracunculus Tarragon 2 lbs Pluchea odorata Marsh fleabane 2 lbs Solidago californica Califomia goldenrod 2 Ibs Notes: *Pounds per acre should be confirmed with the native seed nursery. Pounds may vary based on viability of that particular crop. Brass buttons, fescue and sweet clover deleted (March 16, 2000). The monitoring biologist will be present onsite during the planting and seeding procedures on an as-needed basts. The monitoring biologist should conduct a final check of the site after the planting is complete. The final check will document that plants were appropriately placed by the contractor, and the correct species have been used. P&D Environmental Page 19 City of Carlsbad ;^ Golf Course Riparian Mitigation Plan Understory Container Plantings Wild rose, Mexican elderberry, wild grape, Califomia blackberry, winter current, and spring msh will be planted in container stock. These species -will be planted in clusters to simulate natural conditions. . Wild rose, Califomia blackberry, and spring msh will be used in the buffer (between the native revegetation sites and active use areas) to discourage imauthorized ingress into the mitigation site. Planting methodology will follow standard horticulmral protocol pertaining to hole size, watering, and refilling., Seed Mix The seed mix includes the same species as identified in the Conceptual Mitigation Plan for Reaches 1 and 2 of Cannon Road. This mix utilizes the most common plants found on the site that are commercially available. The seeds for this mix are generally available at several native seed suppliers in Califomia. Following weed removal, alteration of site topography, and installation of container plantings and cuttings, the site will be hydroseeded. The hydroseed mix will include the designated seed mix and a light mulch. The hydroseed mix should be spread over the site to conceal the seed from predators, protect it from -wind and rain erosion, and help retain moisture. The mulch should be made of 93 percent wood cellulose/fiber matrix with 7 percent organic soil stabilizer. • Success criteria refinement The following success criteria and measures that must be implemented in the event that the measures are not being met are provided in the following table. • P&D Environmental Page 20 I I I I I I I I I I I I I I I I I I I City of Carlshad Golf Course Riparian Mitigation Plan Table 6 Project Success Standards and Measures to be Taken if the Standard is Not Met Standard Measure if Standard Not Met Timeframe 70 percent groundcover (visual estimate based on hydroseed developme'nt Reseed/repiant Year 2 Establishment of all species planted Reseed/replant. Substitutions possible Year 2 80 percent healthy container tree plantings Replace with same species/size Year 2 80 percent survival of tree plantings^ Replant Year 2 80 percent survival of remaining shmb plantings 1 Replant Year 2 Height standards met for all trees Replant or receive remedial measures, substitutions possible Year 2 Tree Height Standards^ Cottonwoods 10 feet Sycamore 9 feet Willows •• 11 feet • Mulefat, sandbar willow, elderberry 6 feet Year 3 Year 3 Year 3 Year 3 95 percent survival of tree plaritingsl Replant Year 1 . 80 percent survival of shrub plantings 1 Replant • , Year 1 80 percent groundcover by all.species Additional seed or container plantings as recommended by revegetation designer Year 4 Canopy cover standards met for frees and shmbs Replant or receive remedial measures, substitutions possible Year 2 Canopy Cover Standards3 .Willow riparian woodland 80 percent Brackish marsh 80 percent Year 4 Year 4 Notes: 'Dead container plants can be mitigated for by namrally invading seedlings. ^Mean height in feet. • . . . •"All canopy covers given in percentages. Contingency Measures The project includes a'mitigation monitoring and reporting program, that requires the mitigation to meet the success criteria. Remedial action is proposed if the project does not meet the success criteria. The location of each of the mitigation sites have been selected tp expand existing riparian by conducting minor topographic modifications and revegetating the lowered area. Due-to the success of the Cannon Road site and the'similarities of this proposed mitigation, there is no indication that there should be a failure. However, in the event that the site is considered a failure and remedial actions are unacceptable due to P&D Environmental Page 21 I I I I I I I I City of Carlshad '•' Golf Course Riparian Mitigation Plan engineering, chemical, or physical constraints, the City will work with the Corps, Service and Department in identifying a suitable location for the mitigation. Off-Site The off-site mitigation is proposed to be conducted in the area adjacent to the COSTCO site off of Palomar Airport Road. The mitigation will include an exotic removal program. The site is extensively degraded due to pampas grass. The program -will include the removal (via physical and chemical means) of the pampas grass within a 5.3-acre site. The site will be monitored for five years and remedial actions implemented annually, as needed, to maintain the site. Supplemental planting is proposed to include willow cuttings and application of a seed mix. Annual reports will be pirepared documenting the methodology of the removal, number of plants removed in that year, number of recmits, and overall condition of the site. The program will be deemed successfiil if pampas grass is removed from the site and the disturbed areas are revegetated. There are no contingency measures other than to continue the eradication program if the pampas grass is not deemed eliminated from this parcel at the conclusion of five years. ' fA P&D Environmental Page 22 I ADDENDUM II CARLTAS ENHANCEMENT SITE City of Carlsbad " ' Golf Course Riparian Mitigation Plan Addendum II Carltas Enhancement Site Introduction This report will serve as a supplement to the Carlsbad Golf Riparian Mitigation Plan. Habitat creation for the on-site mitigation plan is detailed in that plan and will be refined in the plans and specifications prepared for implementation. The following is focused on the enhancement ofthe six-acre mitigation site referred to as the "Carltas Site." Figure 1 shows the boundary of the enhancement property. The Carhas Site is located adjacent to Palomar Airport Road, south of the Carlsbad Golf project site. Encinas Creek generally parallels Palomar Airport Road in an east tb west orientation. Much of the area is designated for industrial uses; however, the drainage is proposed as open-space. The Carltas Site has been developed with various uses (including the COSTCO building). The degraded wetlands were designated open space during this entitlement process; however, no enhancement was conducted. The site is currently extensively impacted by the predominance of pampas grass (Cortaderia jubata). Myopiirum laetum has also been identified on the site. It has been considered for enhancement on several occasions.. This project will implement six-acres of enhancement. Based upon conversations with the City of Carlsbad, USFWS, and Califomia Department of Fish and Game (CDFG) it was decided that the westerly-most portion of the site will be enhanced during this program. This is due to the potential spread of the species from the westerly wind pattem. Methodology Site Preparation Site preparation will include a combination of mechanical and chemical removal. Prior to removing the pampas grass, the heads containing seeds will be -wrapped/bagged to reduce the . potential for distribution of seeds during the removal process. Individual pampas grass plants, including the root system, will be removed by hand, if possible. If the entire plant cannot be removed, then the cut base can be painted with an appropriate herbicide, as recommended by the biological monitor. Cut pampas grass shali be removed from the site as soon as practicable to reduce the potential for re-rooting and/or transmission of seeds from the downed material. Myopurum laetumJNUI be manually cut and an approved herbicide applied. Other exotics will be identified and flagged by the monitoring biologist for removal, as appropriate. Planting Guidelines Supplemental planting will be conducted in the area that the pampas grass has been removed. P&D Environmental Page 24 City of Carlshad ' ' Golf Course Riparian Mitigation Plan This will include willow cuttings (sandbar willow,' Salix exiqua; Gooding's willow, S. goodingii; and arroyo -willow, 5. /a^zo/e;?^) found on site as well as mulefat (^acc/zarz^- salicifolia). Four to six-foot segments from the willows will be cut and used for the planting. Three to seven cuttings will be planted in each hole remaining from the pampas grass removal. The number of cuttings will be dependent upon the size of the hole remaining after the pampas grass has been removed. The seed mix that is being used for the riparian revegetation site in Macario Canyon will be used on the enhancement site. Seed will be hand broadcast over the disturbed area. Depending upon the site location, pickleweed (Salicornia virginiata) and cattail (Typha latifolia) may be salvaged from existing stands and transplanted. Cuttings from pickleweed will not affect the root stmcture, but will include segments from the upper portion of the plant. Portions of cattails may be salvaged for ttansplanting with at least one-half of the donor plant remaining. Timing Planting will occur in the late fall to take advantage of the winter rains. This program -will occur during the first fall after constmction of the golf course is initiated. Maintenance and Monitoring The site will be monitored quarterly the first year. Any invasive weeds will be manually removed. If there is evidence of estabhshment of the planted willows/mulefat, no additional action will be required. Some mortality of the cuttings is expected; therefore, if one or more cuttings are established, no remedial action will be required.' It is assumed that each hole will be three to five feet in width; therefore, if one willow tree/mulefat survives, it will provide adequate coverage. Annual monitoring will be implemented for years two through five. Monitoring should take place in late spring/early summer. This will allow young invasive plants to be removed before they have set seed. As indicated above, if a minimum of one cutting becomes established in each area where invasive plant has been removed, or if natural recmitment is noted, no remedial action will be necessary. Maintenance and monitoring will continue through year five or until the site is considered invasive-free for one year. Success Criteria The project will be deemed successful if the site is found to be invasive (pampas grass, Myoporum) free (less than 10% coverage) for a period of one year or-ininihial invasive is noted at the completion of five years. In areas of invasive removal, native groundcover or willows/mulefat should be established either through cuttings or natural recmitment. P&D Environmental Page 25 Figure 1 Boundary for Enhancement Property 1- f.51 r"—' ~rhl3 pill b 16» j-oui lid ill locallna yom Wnd wilt lefereUM (0 itrfteli lod otlia p«j- PARCEL MAP M.S. 837 SURVEY. PROCEDURE . "'"^ SHEET OF B SHEETS LEGEND 777T7 I ".1'. •biv.jcui.c Auocu imu UUJ oek. \ybiii: tliii pisl U Wicvcd to be ™ „ „ CITM«J» JOiTMOUT l»« or Ulf H • b/ relianoe dv<3«<itL. ,( tn««L»' •cn»v IM: if »<*aL A j{ tt-ciitiit OLO I or trntntn KM c in (w I... ^. U.40 » t*,c-* . P*(.OUAR_ Affa^OfiT ff=f^rii minrnriiiniiiinuiniuniiinriiii V lumjix/) - onucirm JOTBC OTY of 1 roR »0«l «*K>S13 JLCCtlTtD is XIX t OM CAStCRLI- Ut£. HCEflXO* (MOD WSTIW «« — , « tcacAm kocWj..V.., BASre OF BEARINGS IHE «j<ss tt tcMotai.rx* THB ttWl •, •,'-• H aa-mcr • Mil UC»1lJUp»1 SIAA**^ M«>TC5 TO. " •*CU. UO«JUCNT STAi^*0 TO r<XV«^ OA OJtlXJNC two U«XSS •ShO»< OIVCffTOSC ...u^- .cxar\^ 1 /(•Aus 1 - ITwclW 1 KU» , o 'Jll.Ol' ' \rt.W n 5ieJM . i«yU' - f! i?a.i» Cl 1«17»- IIXM' y I . f ^ ra. r r lAQOCD J- li p™ POI 'A*. 1 BTzntf (Uaatr) Mxz^iui' AJ 3 D -< cn cs 03 r\ D 3 City of Carlshad Golf Course Riparian Mitigation Plan RemediaL Actions If the site cannot be substantially cleared and maintained "invasive-free" (less than 10% of pampas grass or Myroporum), then the City will work with fhe USFWS/CDFG to determine the appropriate actions. Potential areas of concem include the re-establishment of pampas grass from adjacent stock. 0 ' • . P&D Environmental Page 27