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HomeMy WebLinkAbout3466; OLIVEHAIN RD WIDENING AND REALIGNMENT; THIRD ANNUAL REPORT; 2001-02-01I Third Annual Report i Olivenhain Road Widening Wetland Mitigation Area • Carlsbad, California* H HI I I Prepared for WED • City of Carlsbad • PUblic WOrks Department 2075 Las Palmas Drive FEB ¶ 5 2001 I CärlsbOd, CalifOrnia 92009 ENGINEERING OEPA:RTMENT .1 Li H FebrUary 2001 Li 5510 Morehouse Drive San Diego,.California 92121 I • . ' 1 . I I Third Annual Report . Olivenhain Road Widening, . .. S. Wetland Mitigation Area . • ' '• ..: Carlsbad, California : H Prepared for City of -Carlsbad Public Works Department . . 2015 Las Palmas Drive Carlsbad, California 92009' • . , ..: .- . ,, S - S - Prepared by I AMEC Earth & Environmental, Inc. 5510 Morehouse Drive San Diego, California 92121 I (858) 458-9044 • 5 5 .. I ' February 2001 5 -• - S ' Project No. 315051000 S, I ,' - - S S 5 •5__ . ' i-. , I ;5 • 5 -S I I TABLE OF CONTENTS I SECTION TITLE PAGE INTRODUCTION 1 I i 2 MAINTENANCE AND BIOLOGICAL MONITORING 1 Maintenance Monitoring 1 I Biological Monitoring 4 I 3 SUCCESS STANDARDS 7 4 CONCLUSIONS 8 5 RECOMMENDATIONS 8 6 REFERENCES 10 I LIST OF FIGURES I NUMBER TITLE PAGE i Project Location Map 2 I 2 Site Map 3 LIST OF TABLES 1 NUMBER TITLE PAGE 1 OlivenhainROad Wetland Mitigation Area, Floral Species List, December 1999 6 I I t I f I 315051000 i 1 I I [M I I I 1 INTRODUCTION - I This is the third of five annual reports for the Olivenhain Road Widening Project wetland mitigation area This report covers the period from December 1999 to December 2000 AMEC Earth & Environmental, Inc.. (AMEC) is the biological monitor for the City of Carlsbad (City) to monitor installation and maintenance of the wetland mitigation area or; this project. AMEC did not perform any other biological monitoring functions associated with the road widening project The wetland mitigation area is located along Encinitas Creek south of Olivenhain Road, approximately 0.8 mile east of the, impact area at the intersection of Olivenhain Road and El Camiho Real (Figures 1 and 2) 2 MAINTENANCE AND BIOLOGICAL MONITORING I. •- ' Based on a biological survey and report (Mooney 1991), the City obtained a California .Departhient of Fish and Game (CDFG) Section 1601 Streambed Alteration Agreement No 5-560794 and U.S. Army Corps of Engineers (ACOE) Section 404 Nationwide Permit No. 95-20096-BH to construct the project. The permit requirements included the creation, planting, and 5 years of maintenanci and biological 'Monitoring of 0.5 acre of wetland (0.34 acre southern willow scrub and 0 16 acre freshwater marsh) and 1.1 acres of "riparian scrub transitional habitat at the, top of the dike and on the slopes." AMEC's contract called for three monitoring visits during the third year, which were made in April, July, and August 2000 Maintenance Monitoring The site was well maintained during the first 3 months following planting in late 1997, but mmimal maintenance has taken place in subsequent months and years There has been no maintenance done on this site in the year 2000. Native 'LaiIdscapes, Inc. and the City are finishing up a directive for landscape maintenance at the time of this report In April 2000, AMEC met with Marshall Plantz of the City and Ardis Perry of Native Landscapes to discuss needed remedial measures at this site (see Section 5) At this time it was agreed that Native Landscapes would take on duties as landscape maintenance contractor. ) - •_1".. V 1 315051000 1 V -, I Project Location Map amec*.' I Blology/Oluvenhain 2000/Oluvenhain Proj LocA FH8 -. t t - / CAM/NO :- Al.. VAR-0.1 TT SANTA F R)DG \ - I CARLSBAD TRACT NO B -\6 '5I CCCSS DIRT ROAD / 3 -- OLJ\iNJ-1AIN MUNICIPAL VAT5R PISTRJCT LOT 13 MAP'-NO. 348 - RANC}-iO LAS NCJt'TAS -- WETLAND MITIGATION AREA lil = = = WLEGAND PRDPRTLS Ej\LCJNITAS LOT. 13 MAP ND.. 843 RANCHO LAS NCINTAS vuiisc stwk FOR D(TEW71ON DIKE AND SPILL WAY F.IGURE I :aI717e Site Map : 2 I Biotogy/Olivenhain 2000/Olivenhain Site Map.FH8 3 Li I I I I I I; I, I' I I I , I I Rainfall during the winters of 1998 and 1999 have iesulted in several erosion gullies on the north dike of the site. AMEC first notified the City Of this problem in January 1998: Vegetation has taken over and now shades the, gullies. Many of the willows and other container plants placed in the southern willow scrub area have died and remedial action has been suggested to compensate for them (see Section 5). A portion of the irrigation system has been rendered ineffective because of plant growth around the sprinkler heads, which knocked down most of the water within a few 'feet of 'the sprinklers, resulting in large dry patches and'dying container plants. Weeds have not. been controlled and have gone to seed and died. Portions of the site were impassable because of the, infestation of yellow star-thistle (Centaurea soistitialis) with its numerous sharp thorns. * . Biological Monitoring Most container plants and seeded species are establishing' as expected. Bulrush (Scirpus calfornicus), alkali rush (Scirpus robustus), yerba mansa (Anemopsis californica), 'arrow weed (Pluchea sericea), and narrow-leaved willow (Salix exigua) all began spreading beyond their container plant' basins. These species are forming large spreading clumps and growing into, each other, obscuring their distinction as individual lants. Volunteer invasion by salt marsh species' and certain weeds indicates that wetland conditions have been created in the mitigation area (Reed 198 8). Species designated with the indicator category obligate, wetland (OBL) "occur almost always (estimated probability >99%) under natural conditions in wetlands." The designation facultative wetland (FACW) "usually occur in wetlands (estimated . probability 67-99%), but occasionally found in nonwetlands." The plus (+) sign with facultative species is used to indicate a greater probability toward the higher end of the category estimate. . Volunteer pickJeweed (Salicornia virginica) (OBL), saltgrass (Distichlis spicata) (FACW), and alkali heath (Frankenia sauna) (FACW+) in the lower and more saline, wetter zone of the mitigation area indicates that wetland conditions have been created. Likewise, brass 'buttons (Cotula coronopfolia) and rabbit's foot grass .Polypogon monspliensis) were dominant weeds during the first year of monitoring. Both of these species are classified as facultative wetland (FACW+), also lending support to the notion that wetland conditions, have been created.'. 315051000 ' . . ' A number of species, especially spiny rush (Juncus acutus), were browsed back in year 1 by rabbits but survive and continue to grow. Rabbit control on this site is impractical No other rodent damage was observed in year 2 monitoring. No insect or disease problems were observed As discussed previously, weeds were not adequately controlled and dominate the site in some locations. Because the annual weeds bloomed and set seed, weeds have proven to be a competitive problem Willow mortality was higher than expected at 40 percent because the irrigation system was not kept in good working order during the dry season and many plants died from an apparent lack of water. More drought tolerant species like giant wild rye (Leymus condensatus) and arrow weed were able to survive the dry conditions without significant I I narm. The dikes are establishing well considering the salty soil conditions found there. Annuals like arroyo lupine (Lupinus succulentus) and phacela (Phacelia tanacetfolia).doniinated in the first months, with little seen in the way of perennial speies by the February site visit Most of the perennial species did germinate and are establishing..Giant wild rye, coastal sunflower (Encelia californica), and coastal goldenbush (Isocoma menziesu) are the most dominant native species on the dikes As would be expected, most annual species were dead at the December 1999 -monitoring visit Above average rainfall during the, winter rainy season of 1997-98 probably helped flush some of the excess salts from the surface layer, of soil, improving growing conditions and helping with plant establishment The first annual monitoring took iMace on December 2, 1998. AMEC counted dead container plants, compiled a floral species list, and made observations on plant growth and establishment in the mitigation area Results from the first annual monitoring are in the first annual report Successful volunteer species that contributed significant cover include mule fat (Baccharzs saliczfolza), giant wild rye and arrow weed Table 'l is a floral species list for the Olivenhaiñ Road wetland mitigation area.; The fibral species list covers both the wetland mitigation area and adjacent upland buffer 315051000 5 I Table! I . OLIVENHAIN ROAD WETLAND MITIGATION AREA FLORAL SPECIES LIST . . .5 December 1999 . . . Scientific Name . Common Name Acacia longjfolia . . Sydney golden wattle . Anagallis arvensis . scarlet pimpernel I * Anemopsis calfornica . yerba mansa * Artemisia douglasiana Douglas mugwort * Artemisia calfornica . California sagebrush I * Artemisia Palmeri V Palmer's sagewort W. Atriplex semibaccata Australian saltbush * Baccharis salicfolia mule fat . I * Baccharis pilularis . . coyote bush . Brassica nigra . . black mustard . . . Carpobrotus edulis' . . Hotentot fig I Centaurea so/st itialis yellow star thistle Conyza canadensis . V horseweed Cotula coronopfolia brass buttons V I . Cortaderia sp. S pampas grass ... V Cynara cardunculus V . artichoke thistle . . . Cyperus esculentus V yellow nutsedge I * Distichlis spicata . saltgrass * Encelia calfornica coastal sunflower. .. * Eschscholzia calfornica V California poppy Foeniculum vulgare V fennel I V . * Frankenia sauna V alkali heath V Gnaphalium species .. cudweed . V . * Heterotheca grandora V V V telegraph weed I * Isocoma menziesii . coastal goldenbush * Isomeris arborea bladderpod * Juncus acutus . V . 'spiny rush I * Leymus condensatus .giant wild rye V Lobularia maritima V . sweet alyssum . * Lotus scoparius V V deerweed . I * Lupinus succulent us V arroyo lupine V Melilotus sp. . sweetclover . Myoporum laetum myoporum . V I * Oenothera hookeri .. . Hooker's evening primrose V V Pennisetum clandestinum . Kikuyugrass I * Phacelia tanacetfolia Picris echioides . . V Phacelia . V bristly ox-tongue V V V * Pluchea sericea . . arrow weed Polypogon monspliensis . . . rabbit's foot grass I 315051000 I ' ': •. . . i' . •' .. . . S Table 1 (Continued) , I , OLIVENBAIN ROAD WETLAND MITIGATION AREA FLORAL SPECIES LIST 1999 I December '. . ' Common Name Scientific Name I . -Raphanus sativus . wild radish * Rhus integrfolia . lemonade berry Rumex crispus curly dock I . * Salicorñza virginica pickleweed . * Salix exigua , narrow-leaved willow * Salix lasiolepis . ' arroyo willow . ,Salsola tragus , Russian thistle I * Sambucus mexicana , Mexican elderberry * Scirpus ca1fornicus •, bulrush .. * Scirpus robusta '' . alkali rush . . I Sonchus oleraceus . .: annual sow thistle Washingtonia robusta , , Mexican fan palm I Unidentified annual grasses -- * Denotes species native to San Diego County I . ' including the dikes. A total of 51 species have been observed at the project site to 'date, several unidentified grasses. I plus 3 SUCCESS STANDARDS Specific tree height standards have not been designated' for this project, but the Section I 1603 Streambed Alteration Agreement calls for tree and shrub heights to be collected and discussed in the annual report. Tree and shrub heights were not, collected as part of biological monitoring for the project, so they were not assessed. Success standards for I the project require 80 percent container plant survival at year 1, and 100' percent thereafter. For the upland dikes portion of the project, container plant survival was 60 percent, I falling below the 80 percent success standard. For the wetland portion of the project, container plant survival is 95 percent, meeting the 80 percent success standard. The' standards also require 75 percent cover after. 3 years and 100 percent after 5 years. The project did not meet its third year success standard for cover, but AMEC believes the I ' 315051000 - S ' 7 I project can meet its third year success standard of 75 percent cover in year 4, if : recommendations included here are followed. : . .. I / 4 CONCLUSIONS Native species cover is developing at a satisfactory'rate, however invasive exotic pampas . . I grass (Cortaderia sp.) is a major concern at this time. In addition, remedial planting measures will need to be taken to achieve year 5' cover standards of 100 percent (see I Section 5). .. .. . I In year 1, container plant survival fell below success standards on the dike structure, but met standards in the wetland portion of the site. Despite meeting overall success U standards in the wetland, willows did not meet survival standards at 77: percent. AMEC :. attributes the loss of willows to a lack of irrigation during the dry season. The young willows had not become established. enough to survive without irrigation during the I summer. I ' After year 2, it appears wetland has been sucessful1' created in the wetland mitigation area because obligate wetland and facultative 'wetland species have volunteered into the project. With adequate maintenance to ensure the establishment of desirable . native species and to keep invasive exotic weed species under control, the mitigation should I . ultimately prove successful. . . .: . . . . . .. 5 RECOMMENDATIONS For year 3 of the 5-year maintenance' and'monitoring program, AMEC recommends the I following items be completed by the City: . , r 1'. Set Up a meeting between AMEC and the maintenance supervisor to ensure the maintenance cre*, knows all the species present and which weed species should be controlled. .. .. . . * -. . 2. Repair erosion gullies on' the dike using 1-gallon. potted, giant wild rye I - - (Leyrnus condensatus).-- I I 315051000 8 / I Plant 125 container plants using approximately equal proportions of California I sagebrush (Artemisia caljfornica), mule fat (Baccharis salicfolia), giant wild rye (Leymus condensatus), Palmer's sagewort (Artemisia palmeri), arrow I weed (Pluchea sericea), and narrow leaf willow (Salix exigua). The plants should be ordered for September delivery from Tree of Life Nursery in San I . Juan Capistrano (949) 728-0685,, or another native plant supplier. Keep the irrigation system off during the rainy season so long as rainfall is adequate to keep the plants healthy. Begin irrigating again in spring as the' rainy season comes to an end: 'Inspect the irrigation system regularly and I . . prune growth around sprinkler heads, as needed, to maintain adequate sprinkler coverage. I : . 5. Apply agricultural gypsum at the rate of,20 pounds per 1,000 square .feet and Sarvon wetting agent, or approved equal, at the rate of 1 pint per 1,000 square I . feet, to, all growing areas of the project site. I . .6. Control all growth around container plants until the plants are established' enough to avoid being out competed, and to facilitáté biological monitoring. AMEC can point out to the landscape maintenance supervisor which plants no ' longer require clearing. I 7. Control the following invasive exotic weed species whenej'er they appear onsite: salt cedar (Tamarix sp.), pampas grass (Cortaderia sp.), castor, bean I (Ricinus communis), fennel (Foeniculum vulgare), common cocklebur (Xanthium strumarium),' gum tree seedlings (Eucalyptus sp.), yellow star- thistle (Centaurea soistitialis), and giant reed (Arundo donax).' ' ' •, . . I . . 8. Control annual weeds to keep them from becoming competitive and dominant. . '. Species that.were in need of control in year 1 that may 'need continuing control I . measures include black mustard (Brassica nigra), wild radish (Rap hanus sativus), milk thistle (Silybum marianum), bur clover (Medicago hispida), and sow thistle (Sonchus asper). '315051000 0 ' '' 0, ,' , , •, , 0,, , . I I 6 REFERENCES I Brian F Mooney Associates 1991 Biological survey and report for the Olivenhain Road widening/realignment and flood control project. June. I Reed, Jr, Porter B 1988 National list of plant species that occur in wetlands California (Region 0) May. I I I I I • 0 I I p I 4 I I I 4 I I I 315051000 10