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Home My WebLink About3537; North Agua Hedionda Interceptor West Segment; North Agua Hedionda Interceptor West Segment; 2010-03-01FINAL MONITORING REPORT forthe NORTH AGUA HEDIONDA INTERCEPTOR WESTERN SEGMENT REALIGNMENT PROJECT Prepared for: City of Carlsbad 1635 Faraday Avenue Carlsbad, California 92008 Contact; Mork Biskup 760 602 2763 Prepared by: 605 Third Street Encinitas, California 92024 Contact: Vipul Joshi vjoshi@dudek.com MARCH 2010 Printed on 30% post-consumer recycled material. Final Monitoring Report for the North Agua l-ledionda Interceptor Western Segment Realignment Project TABLE OF CONTENTS Section Page No. 1.0 INTRODUCTION 1 2.0 PROJECT CONSTRUCTION/MONITORING ACTIVITIES 1 2.1 Western Staging Area 2 2.2 Central Staging Area 2 2.3 Eastern Staging Area. 8 3.0 IMPACTS 8 3.1 Post-Construction Survey 9 3.2 Impacts Summary '. 10 4.0 MITIGATION 10 APPENDIX A Photo Documentation LIST OF FIGURES 1 Regional Map 3 2 Vicinity Map 5 3 Impact Map 11 6520-01 DUDEK March2010 Final Monitoring Report for the North Agua Hedionda Interceptor Western Segment Realignment Project INTENTIONALLY LEFT BLANK DUDEK 6520-01 March 2010 I I 1 I I I I 1 I I I I I I I I I I I I I i I I I I I 1 I I I t I 1 I I Final Monitoring Report for the North Agua Hedionda Interceptor Western Segment Realignment Project 1.0 INTRODUCTION The purpose of this final monitoring report is to summarize the construction and monitoring activities of the completed North Agua Hedionda Interceptor (NAHI) Western Segment Realignment Project (Project) arid related impacts to demonstrate compliance with the permit conditions set forth in Coastal Development Permit No. 6-07-92 issued by the California Coastal Commission (CCC) August 12, 2008. The NAHI Project is constructed primarily by means of micro-tunnel installation, as opposed to traditional trench excavation and installation. Consequently, the impacts of the Project are limited to construction staging areas and access roads. The Coastal Development Permit (CDP) requires that all staging and storage areas be maintained within the proposed staging areas located outside of sensitive habitat. The Project's construction monitoring activities are provided here to demonstrate compliance with this condition. This report also provides the results of a 90- day post-construction survey conducted February 23, 2010, as required under CDP. The applicant for the Project is the City of Carlsbad (City). The Project involved relocating the existing NAHI located along the northern shoreline of the Agua Hedionda Lagoon farther inland using micro-tunneling techniques. The Project site is located in the City, within the County of San Diego, California. The Project site is located along the north shore of Agua Hedionda Lagoon from Hoover Street in the west to Cove Drive in the east. It is situated on the U.S. Geological Survey 7.5-minute San Luis Rey topographic quadrangle, Section 8, Range 4 West, Tovraship 12 South (Figures 1 and 2). 2.0 PROJECT CONSTRUCTION/MONITORING ACTIVITIES Construction began on February 2, 2009, with clearing of the western staging area. Construction monitoring was conducted to ensure compliance with permit conditions regarding avoidance of native biological resources. Monitoring confirmed compliance with the CDP Special Condition (SC) #8 that all staging and storage areas shall be maintained within the proposed staging areas located outside of sensitive habitat. Photographs for photo documentation were taken during each site visit. Pre-construction, during construction, and post-construction photographs are provided in Appendix A. The monitor also attended weekly progress update meetings during the initial stages of the Project. 6520-01 DUDEK 1 March 2010 Final Monitoring Report for the North Agua Hedionda Interceptor Western Segment Realignment Project 2.1 Western Staging Area Vegetation was cleared and silt fencing installation began February 2, 2009, prior to drill arrival on site. This area was mapped as disturbed habitat and consisted primarily of fig-marigold {Carpobrotus edulis). There were no impacts to native vegetation. The coastal salt marsh along the southern boundary was not included within the staging area as this area did not require disturbance. ^ The vegetation clearing initially followed the flagging that had been established prior to construction. However, after referencing the construction plans, it became clear that the global positioning system (GPS) used to delineate the boundaries must have not been calibrated correctly. Triangulation was used to correct this error, making the staging area extend farther west on the western side. No native vegetation was impacted as a result of this change. Vegetation clearing continued and pipes were unloaded onto the staging area February 4, 2009. Drilling began after this and continued through February 11, 2009. A steel pipe was installed after drilling ceased. Work subsequent to that included filling the pipe and moving material around to set up the staging area. The steel pipe had been installed and the drill was no longer set up at this staging area by February 13,2009. The construction trailer was set up at this staging area in March. 2.2 Central Staging Area Dudek biologists flagged and recorded the limits of native vegetation using a global GPS prior to construction on September 25, 2008. This established the limit of work outside of coastal sage scrub habitat. Trenching for the installation of silt fencing began February 2, 2009, and installation was completed February 4, 2009. Sandbags were placed along fencing on February 5, 2009. Grading of disturbed vegetation followed installation of silt fencing. _______ 6520-01 UUDEK 2 March2010 Pacific Ocean Mexico DUDEK 6520-01 MARCH 2010 FIGURE 1 Regional Map FINAL MONITORING REPORT for the NORTH AGUA HEDIONDA INTERCEPTOR WESTERN SEGMENT REALIGNMENT PROJECT DRAFT Final Monitoring Report for the North Agua Hedionda Interceptor Western Segment Realignment Project INTENTIONALLY LEFT BLANK 6520-01 DUDEK 4 March 2010 Final Monitoring Report for the North Agua Hedionda Interceptor Western Segment Realignment Project INTENTIONALLY LEFT BLANK _ , ,r^g-t, 6520-01 DUUCK 6 March 2010 Final Monitoring Report for the North Agua Hedionda Interceptor Western Segment Realignment Project Dudek biologists walked the perimeter of the staging area, which was already flagged, with the contractor as he painted the limits for the installation of the silt fencing to ensure no native vegetation would be impacted. Silt fencing was installed outside of all native vegetation (i.e., coastal sage scrub). The surveyors established where the drill pit would be placed on February 4, 2009. There was an approximate 20-foot buffer around this location, which enabled the crew to install and operate the drill without extending the silt fencing outward and impacting coastal sage scrub. Grading continued within the limits established by the silt fencing to improve the access "road" through the staging area for the drill rig to be moved to this location February 12, 2009. i The drill rig was set up at the southern end of the staging area. A sound wall intended to reduce noise levels at adjacent occupied California gnatcatcher {Polioptila californica) habitat was installed. The sound wall consisted of K-rails with 20-foot-high posts lined with plywood and sound blankets and was located around the area where the drill was to be operating in the southern portion of the central staging area. A Dudek biologist reported at the weekly update meeting on February 18, 2009, that although the Project was out of compliance with the Mitigated Negative Declaration (MND) regarding California gnatcatcher mitigation, both the City and the U.S. Fish and Wildlife Service (USFWS) were in agreement that work could be allowed to continue given the establishment of a sound barrier. California gnatcatcher monitoring had not reported the birds to be nesting at that time. Drilling at the central staging area was scheduled to begin February 19, 2009, and be completed February 25, 2009. At the subsequent weekly update meeting, the status of the California gnatcatcher was discussed. Specifically, the birds were found nesting on February 23, 2009, and the agencies (California Department of Fish and Game (CDFG) and USFWS) had been notified. California gnatcatcher monitoring would no longer be necessary and noise walls would remain in place at that time. Drilling at this staging area was competed February 26, 2009 and demobilization followed. Roads were closed as the drill was moved from the work area. At the weekly update meeting on March 4, 2009, it was reported that the California gnatcatcher should not be a concern unless noise levels increased. However, it was agreed that the issue would remain on the agenda to address potential noise increases associated with mobilization of the micro-tunneling effort, which was not scheduled until April. 6520-01 DUDEK 7 March 2010 Final Monitoring Report for the North Agua Hedionda Interceptor Western Segment Realignment Project The sound wall was restored after wind knocked it down in late March. While the noise wall was beneficial and the resource agencies had asked for it during the drilling phase of the Project, dismantling it at this stage was determined to not be a concern. Micro-tunneling from the center staging area westward begari in April. The noise generated by the micro-tunneling process was generally lower than the ambient noise generated from freeway traffic near the California gnatcatcher nest location. 2.3 Eastern Staging Area On February 24, 2009, silt fencing was installed where a 15-foot-wide easement exists. Native vegetation was flagged at this staging area. An area of approximately 8 x 15 feet located at the northeastern edge of the coastal sage scrub would be impacted by the installation of a 6- inch pipeline. This area primarily consisted of an immature stand of California encelia (Encelia californica), but also included prickly-pear cactus (Opuntia littoralis), California sagebrush {Artemisia californica), California buckwheat (Eriogonum fasciculatum), coyote bush (Baccharis pilularis), and deerweed {Lotus scoparius), all small in stature. Mustard {Sisymbrium sp.) and bare ground also composed approximately 25% cover in this area. However, this area does not require additional mitigation, since it had already been mitigated for and thus authorized by the CCC for impact. The City and Dudek reviewed the existing conservation credit purchase agreement and acknowledgement obtained by the property owner, and determined that the impacts would be allowable under the existing agreement. The conservation credit purchase agreement and acknowledgement confirmed that the property owner had purchased 0.5 credit fi-om the Carlsbad Highland Conservation Bank for construction of a two-story single-family residence at 4485 Adams Street in the City of Carisbad (APN 206-200-04), for which the CCC had issued a permit (Application No. 6-68-14) in 1998. Initial work at the eastern staging area involved prepping for the installation of the 6-inch pipeline, which involved excavating a trench north of the silt fencing. 3.0 IMPACTS Hydroseed application followed completion of construction and was completed November 23, 2009. Hydroseed was applied to all impacted staging areas in accordance with the landscaping/replanting plan. Biological monitoring was conducted to ensure the correct seed mix was applied in the appropriate manner. The following species were included in the hydroseed mix: _ , — 6520-01 DUUCK 8 March 2010 Final Monitoring Report for the North Agua Hedionda Interceptor Western Segment Realignment Project Big saltbush {Atriplex lentiformis) Bush monkey flower {Mimulus aurantiacus var. aurantiacus) Common yarrow {Achillea millefolium) Golden-yarrow {Eriophyllum confertiflorum) Salt heliotrope {Heliotropium curassavicum) Deerweed Purple needlegrass {Nassella pulchra) Foothill needlegrass {Nassella lepida) Coast range melic {Melica imperfecta) Salt grass {Distichlis spicata) Deergrass {Muhlenbergia rigens) California poppy {Eschscholzia californica) Owl's-clover {Castilleja exserta) Miniature lupine {Lupinus bicolor) Arroyo lupine {Lupinus succulentus) Dot-seed plantain {Plantago erecta) Fringed willowherb {Epilobium ciliatum), which replaced hummingbird trumpet {Epilobium canum) after approval due to availability. 3.1 Post-Construction Survey A post-construction survey was conducted February 23, 2010, by Dudek biologist Kathleen Dayton (from 8:15 a.m.-9:45 a.m.; conditions were surmy, clear, little to no wind). Each stagirig area was walked and observations regarding existing conditions in terms of impacted areas, vegetation, and general site conditions were recorded. Photographs wei"e taken to document conditions and the location of the silt fencing was recorded with a GPS unit to document the final limits of impact. The silt fencing installed prior to construction was still standing. Straw wattles were also still in place as erosion control features at each staging location. Fericing to control access had been installed along the northern boundary of the central staging area and along the road at the eastern staging area. DUDEK 6520-01 March 2010 I Final Monitoring Report for the | North Agua Hedionda Interceptor Western Segment * Realignment Project No impacts outside of the established silt fencing were evident at the time of the post- construction survey at each staging area. Minimal evidence of erosion was present at each staging area. Total vegetative cover of the hydroseeded western staging area was relatively low. However, evidence of hydroseeded plants were observed, such as lupine {Lupinus sp.), purple owl's-clover, and dot-seed plantain. Vegetative cover along the edges of the staging area was greater than at the center, which was covered by more bare ground. Total vegetative cover was greater at both the central and eastern staging areas. These areas were primarily dominated by ||| non-native species, including mustards and wild radish {Raphanus sdtiva). Since impacts were limited to approved staging area locations within disturbed/non-native habitat and previously mitigated land, no temporary impacts remain that would require additional mitigation or restoration. 6520-01 DUDEK 10 March 2010 I I I 3.2 Impacts Summary | I Impacts documented during NAHI western segment alignment activities did not exceed the permitted impacts (Figure 3). The western staging area consisted entirely of disturbed habitat dominated primarily by fig-marigold. The cismontane alkali marsh south of this staging area was not impacted. All of the coastal sage scrub was avoided at the central staging area via pre- construction flagging and verified during monitoring of silt fence installation. Although minor impacts to native vegetation occurred at the eastern staging area (120 square feet), this area was previously mitigated. I 4.0 MITIGATION 1 1 I 1 The City plans to maintain the staging areas for at least 1 year and maintenance needs will be re- evaluated in the future in order to meet the 5-year standard stipulated in the CDP. The CDP requires a landscape monitoring report to be completed 5 years from the date of issuance of the permit (issued March 6, 2008). This report will include photo documentation of plant species and I coverage in order to ensure that all on-site landscaping complies with the approved landscape/planting plan. A revised supplemental landscape plan will be required if landscaping is ^ not in conformance with the landscape/planting plan or if it has failed to meet the specified .1 performance standards. I I I I DUDEK 6520-01 MARCH 2010 SOURCE: DIGITALGLOBE 2008. FIGURE 3 Impact Map FINAL MONITORING REPORT forthe NORTH AGUA HEDIONDA INTERCEPTOR WESTERN SEGMENT REALIGNMENT PROJECT DRAFT DUDEK Final Monitoring Report for the North Agua Hedionda Interceptor Western Segment Realignment Project INTENTIONALLY LEFT BLANK 12 6520-01 March 2010 APPENDIX A Photo Documentation APPENDIX A Photo Documentation PRE-CONSTRUCTION Western Stage Pre-construction Survey. Photo taken 1/22/09 Pre-construction Survey. Photo taken 1/22/09 DUDEK A-1 6520-01 March 2010 APPENDIX A (Continued) Central Stage Pre-construction Survey. Photo taken 9/25/08 Pre-construction Survey. Photo taken 9/25/08 DUDEK A-2 6520-01 March 2010 APPENDIX A (Continued) Pre-construction Survey. Photo taken 9/25/08 Pre-construction Survey. Photo taken 9/25/08 DUDEK A-3 6520-01 March 2010 APPENDIX A (Continued) Pre-construction Survey. Photo taken 9/25/08 Pre-construction Survey. Photo taken 9/25/08 DUDEK A-4 6520-01 March 2010 APPENDIX A (Continued) Eastern Stage Pre-construction Survey. Photo taken 1/22/09 Pre-construction Survey. Photo taken 1/22/09 DUDEK A-5 6520-01 March 2010 APPENDIX A (Continued) DURING CONSTRUCTION Western Stage Vegetation clearing of staging area and silt fence installation. Photo taken 2/2/09. Staging area set-up. Photo taken 2/3/09. DUDEK A-6 6520-01 March 2010 APPENDIX A (Continued) Set-up with construction trailer. Photo taken 5/28/09. Central Stage Silt fence installation and vegetation clearing. Photo taken 2/4/09. DUDEK A-7 6520-01 March 2010 APPENDIX A (Continued) Stage preparation for drill rig set-up. Photo taken 2/11/09. Drill and sound wall. Photo taken 2/19/09. DUDEK A-8 6520-01 March 2010 APPENDIX A (Continued) Micro-tunneling. Photo taken 4/14/09. Eastern Stage Excavation for installation of the 6-inch pipeline. Photo taken 3/4/09. DUDEK A-9 6520-01 March 2010 APPENDIX A (Continued) Pipeline installation prep. Photo taken 3/16/09 POST-CONSTRUCTION Western Stage Post-construction Survey. Photo taken 2/23/10 DUDEK A-10 6520-01 March 2010 APPENDIX A (Continued) Post-construction Survey. Photo taken 2/23/10 Central Stage Post-construction Survey. Photo taken 2/23/10 DUDEK A-11 6520-01 March 2010 APPENDIX A (Continued) Post-construction Survey. Photo taken 2/23/10 Post-construction Survey. Photo taken 2/23/10 DUDEK A-12 6520-01 March 2010 APPENDIX A (Continued) Eastern Stage Post-construction Survey. Photo taken 2/23/10 Post-construction Survey. Photo taken 2/23/10 DUDEK A-13 6520-01 March 2010 APPENDIX A (Continued) INTENTIONALLY LEFT BLANK 6520-01 DUDEK A-14 March 2010