The URL can be used to link to this page

Home My WebLink About3821; LAKE CALAVERA REMEDIAL/ MITIGATION PROJECT; OAK TREE INVENTORY; 2004-06-07P ___LAND USE/COASTALPLANNING NING LANDSCAPE ARCHITECTURE • LA3900 EMS POLICY AND PROCESSING ENVIRONMENTAL MITIGATION I June 7, 2004 Michael Grim City of Carlsbad 1635 Faraday Avenue Carlsbad, California 92008 SUBJECT: OAK TREE INVENTORY Lake Calavera Temporary Water Drawdown Project Carlsbad, California Mr. Grim, The City of Carlsbad proposes the drawdown of water from Lake Calavera to perform as- needed maintenance. A Biological Resources Report (BRR) of the Lake Calavera study area by Merkel &t Associates in 2002 determined that impacts to sensitive biological 'resources are anticipated by the project. A Notice of Intention to Adopt a Mitigated Negative Declaration (MND) was prepared and was submitted to resources agencies for comment, including the U.S. Fish and Wildlife Service and the California Department of Fish and Game. The Agencies have commented on the MND and offered recommendations to assist the City, as stated in Recommendation #11, contained in a letter to Mr. Michael Grim (FWS7- SDG-3977.1). In satisfaction of Recommendation #11, this letter report provides an inventory of oak trees in the study area, including oaks likely to be impacted by the project. Recommendation #11 11. In,general, the Department' supports woodland mitigation efforts that would create, enhance, or preserve replacement habitat that is ecologically connected and functional. An ecological V restoration approach that emphasizes woodland habitat values may result in better quality habitat being established in appropriate locations. So that we can assess if the proposed oak tree' mitigation is of equivalent biological value to the oak trees that will be impacted, the final MND should list the diameter at breast hight(ic) (DBH) of each oak tree that will be. impacted and the DBH of each oak tree' that will be preserved The following replacement ratios (using rooted plants in liners' or direct planting of acorns) are recommended for oak trees that are removed: 1 trees less than 5 inches DBH should be replaced at 3:1 trees between 5 and 12 inches DBH should be replaced at 5:1 , trees between 12 and 3,6 inches DBH should be replaced at 10:1 4., trees greater than 36 inches DBH should be replaced at 20:1 ' V 1530 FARADAY AVENUE • SUITE 100• CARLSBAD, CA 92008 • (760)931-0780 - FAX (760)931-5744-planningsystems@nctimes.net I I I I Ii I I The replacement ratio for damaged trees less than 12 inches DBH should be 2:1, and greater than. 12 inches DBH should be 5:1. All other oaks should be fenced off and tagged to prevent equipment from operating in the drip line of these trees. Study Methodology The BRR identifies two oak species occurring in the study area, Coast Live Oak (Quercus agrzfolia Nee), and Scrub Oak (Quercus berberidifolia leibm.). Scrub oak is considered a shrub in authoritative references including The Tepson Manual, Higher Plants of California; therefore this species is excluded from this study. Tree diameter is the most important measurement of standing trees. Diameter is measured at 4-1/2 feet above the ground (foresters refer to this as the diameter at breast height or DBH) on the main stem. DBH is recorded by one-inch classes. As an example, trees with a DBH between 5.6 inches and 6.5 inches would be assigned a value of 6 inches when information is recorded. I Coast live oak is a colonizing species often producing multiple trunks (branches) diverging below, at, or within a few feet above the soil surface. If a fork appears below breast height, I the tree is considered to be two separate trees, and a separate measurement is recorded for each tree. If there are branches or other projections at DBH, the measurement is taken immediately above the branch or projection. The BR study area is significantly larger than the area potentially impacted by the project. For the purposes or this report, study areas that will not be impacted by the proposed project will be called preserve areas. The location where project related impacts may occur, associated with the drawdown in water level of the reservoir, is termed the "Project Biological Impact Zone" (PBIZ), mapped and described in the BRR. Coast live oaks existing in the PBIZ will be inventoried as per the forester's conventions described above. Coast live oaks existing in the preserve area will be inventoried similarly, but utilizing a more generalized estimate of individuals. Inventory Results Quercus agrifolia trees in the study area are 1)l(ocated in association with the riparian habitat of Calavera Creek, which outfalls into Lake Calavera, and 2) located near Lake Calavera itself. With the exception of two mature oaks occurring on the south shore of lake Calavera, and one mature oak with collapsed trunks occurring on finger extension along the northern shore of Lake Calavera, all oaks appeared to be in a generally healthy and vigorous state. Oak tree No. "iz4" is damaged, its trucks have collapsed and are now resprouting from the base. Oak tree No. "iz39" is thinly leafed out, indicating existin g weakness or poor health. Oak tree No. "iz40" appears to be dead. Oaks inventory results are provided in tables 1 and 2. Table 1 identifies oaks located in t h e PBIZ as described in the Biological Report, and Table 2 identifies oaks of the study area n o t I located in the PBIZ (oaks to be preserved undisturbed in place). The PBIZ is the limi t o f area which could, under worst-case conditions, experience vegetation impacts or lo s s I through implementation of the proposed project. Table 1— CLO in the PBIZ ioi 1DB No; DBH No :BI r ISS izi 3" izil 15" iz21 18" iz31 16" iz41 9" iz2 13" izZ12 16" 1z22 4" iz32 14" iz42 10" iz3 15" iz13 12" 1z23 3" iz33 23" iz43 16" iz4 12" iz14 3" iz24 17" iz34 4' iz44 4" iz5 12" iz15 17" iz25 9" iz35 2" iz45 15" iz6 5" iz16 9" iz26 28" iz36 9" 1z46 17" iz7 5" iz17 10" iz27 {14" iz37 19" 1z47 23" 1z8 5" iz18 12" iz28 7" iz38 6" 1z9 5" iz19 8' iz29 11" 1z39 16" iz10 5" iz20 7" iz30 17" iz40 dead Table 2— CLO Outside of the PBIZ 7' BIi BH DBH I1O D$M 3B*' J-I P1 4" P15 12" P29 20' P43 10" P57 12" P71 6" P85 P2 5" P16 3" P30 14' P44 3" P58 14" P72 6" P86 3" P3 4" P17 3" P31 12" P45 16" P59 14" P73 8" P87 1 4" P4 5" P18 8" P32 4" P46 20' P60 16" P74 10" P88 20" P5 23" P19 9" P33 7" P47 12" P61 5" P75 5" P89 20" P6 9" P20 7" P34 4" P48 18" P62 4" P76 6" P90 8" P7 8" P21 3" P35 4" P49 14" P63 14" P77 6' P91 6" P8 6" P22 5" P36 4" P50 2" P64 6' P78 7" P92 10" P9 8" P23 3" P37 6" P51 20" P65 10" P79 6" P93 12" P10 5" P24 2" P38 3" P52 8" P66 8' P80 1" P94 6" P11 6" P25 7" P39 7" P53 16" P67 6' P81 7" P95 10" P12 19" P26 6" P40 8" P54 14" P68 6" P82 6" P96 12" P13 14" P27 7" P41 5" P55 12" P69 14" P83 4" P97 9" P14 3" P28 12" P42 5" P56 4" P70 ILE84 22" Coast Live Oak Impacts and Mitigation Measures Coast live oak is an upland species that typically does not require wetland conditions to persist. The BRR has determined that most of the Coast Live Oak occurring in the study area are not hydrologically supported by the Lake. However, some CLO trees existing close to the Lake Calavera shoreline and may be utilizing lake moisture. Resource Agencies are concerned that these trees may be stressed as a result of the drawdown of lake water, to the extent that tree damage may occur. Project related oak tree damage may not be readily apparent during project activities. The resources agencies are evidently recommending that mitigation is implemented for all oaks located within the PBIZ, per FWS-SDG-3977.1, Recommendation #11. The recommended mitigation measures for coast live oak trees within the PBIZ per FWS- SDG-3977.1, Recommendation 11 are tallied in Table 3 below. Table 3 - Replacement Schedule to mitigate CLO in the PBIZ ais 1es 23 Less than 12" 2:1 46 23 Greater than 12" 5:1 115 TOTAL 46 161 To comply with FWS-SDG-3977.1, Recommendation #11, 161 Quercus agrifolia acorns or seedlings must be planted to mitigate for anticipated worst case project related impacts. No Coast Live Oaks are scheduled for "removal "as a result of the proposed project, so the mitigation measures for replacing "removed" oak trees in Recommendation #11, are not applicable to this project, and are not addressed in this report Sincerely, Greg Evans, Restoration Ecologist Planning Systems NORTH SCALE: - 1"= 400' COAST LIVE OAK INVENTORY OAKS IN PBIZ IN PRESERVE AREA No. DBH No. DBH No. DBH Izi 3' P1 4' P51 20' Iz2 13' P2 5' P52 8' Iz3 15' P3 4' P53 16' Iz4 12' P4 5' P54 14' Iz5 12' P5 23' P55 12' Iz6 5' P6 9' P56 4' Iz7 5' P7 8' 5P7 12' Iz8 5' P8 6' 5P8 14' Iz9 5' P9 8' P59 14' izl0 5' P10 5' P60 16' izil 15' P11 6' P61 5' 1z12 16' P12 19' P62 4' Iz13 12' P13 14' P63 14' Iz14 3' P14 3' P64 6' Iz15 17' P15 12' P65 10' Iz16 19' P16 3' P66 8' Iz17 10' P17 3' P67 6' Iz18 12' P18 8' P68 6' 1z19 8' P19 9' P69 14' Iz20 7' P20 7' P70 5' Iz21 18' P21 3' P71 6' Iz22 4' P22 5' P72 6' Iz23 3' P23 3' P73 8' Iz24 17' P24 2' P74 10' Iz25 9' P25 7' P75 5' Iz26 28' P26 6' P76 6' Iz27 14' P27 7' P77 6' Iz28 7' P28 12' P78 7' 1z29 11' P29 20' P79 6' 1z30 17' P30 14' P80 1' z31 16' P31 12' P81 7' Iz32 14' P32 4' P82 6' Iz33 23' P33 7' P83 4' Iz34 4' P34 4' P84 22' Iz35 2' P35 4' P85 6' Iz36 9' P36 4' P86 3' Iz37 19' P37 6' P87 4' Iz38 6' P38 3' P88 20' Iz38 16' P39 7' P89 20 1z40 dead P40 8' P90 8' Iz41 9' P41 5' P91 6' 1z42 10' P42 5' P92 10' 1z43 16' P43 10' P93 12' Iz44 4' P44 3' P94 6' Iz45 15' P45 16' P95 10' Iz46 17' P46 20' P96 12' Iz47 23' P47 12' p97 9' P48 18' P49 14' P50 2' PROJECT BIOLOGICAL IMPACT ZONE THE PROJECT BIOLOGICAL IMPACT ZONE (BPIZ) IS THE AREA OF PROJECT IMPACTS AS DEFINED BY THE BIOLOGICAL RESOURCES REPORT, LAKE CALAVERA, APRIL 18, 2002, MERKEL & ASSOCLATES. BPIZ OAKS REQUIRE MmaAnoN BASED ON THEIR DIAMETER AT BREAST HEIGHT (DBH). OTHER OAKS IN THE STUDY AREA WiLL BE PRESERVED UNDISTURBED IN PLACE. SURVEY NOTE: FIELD SURVEYED ON MAY 24 & 25, 2004 BY PLANNING SYSTEMS FOR COAST LIVE OAK RESOURCES. MAPPING BY PLANNING SYSTEMS, INTERPRETED FROM ¶AKE CALAVERA BIOLOGICAL RESOURCES MAP, MERKEL & ASSOCIATES, MAY 1, 2003. Coast Liv Lake Calavera Carlsbad, California hv entory LEGEND syrn description _____ COAST LIVE OAK (per Biological Resources Report) COAST LIVE OAK (identified by Planning Systems) [. COAST LIVE OAKS IN PROJECT BIOLOGICAL IMPACT ZONE FP 4 COAST LIVE OAKS IN AREAS NOT IMPACTED BY PROJECT EXISTING LAKE CALAVERA SHORELINE — PROJECT BIOLOGICAL IMPACTS BOUNDARY (PBIZ) STUDY AREA BOUNDARY Ps# JUNE 7, 2004 0 400 Figure 1 C: PSPROJECTS\LAKE CALAVERA\LC OAKS INVENTORY 6104. DWG References Hickman, J.C., Editor, 1993, The Jepson Manual, Higher Plants of California. University of California, Berkeley, CA, pp. 1392. Merkel &z Associates, Inc., May 1, 2003, Biological Resources Report, Lake Calavera. Roberts, Fred M., 1995, Illustrated Guide to The Oaks of the Southern Californian Floristic Province, The Oaks of Coastal Southern California and Northwestern Baja California, Mexico, F. M. Roberts Publications, Encinitas, California. pp. 112. Sawyer, J.O. and Keeler-Wolf, T.,1995, A Manual of California Vegetation. California Native Plant Society, Sacramento, CA. pp. 471. U.S. Fish and Wildlife Service, Letter to Mr. Michael Grimm (FWS-SDG-3977.1). University of Minnesota Extension Service, 1998, Sampling and Measuring Timber in the Private Woodland, www.extension.un-lrLedu/distrlbutlon/naturalresources/components/DD3025-03.hmtl