HomeMy WebLinkAbout3008; Calavera Creek Channel Mitigation Monitoring; Calavera Creek Channel Mitigation Monitoring; 2011-04-13Annual Mitigation Monitoring Report for 2010 Calavera Creek Channel Protection Project Carlsbad, California Plot 1, April 16,201 1 April 13,20 1 i Prepared for: BROOKFIELD HOMES 12865 Pointe Del Mar, suite 200 Del Mar, CA 92014-3859 Prepared by: PLANNING SYSTEMS 1530 Faraday Avenue, Suite 100 Carlsbad, CA 92008
Annual Mitigation Monitoring Report for 2010 Calavera Creek Channel Protection Project Carlsbad. California Table of Contents page ................................................................................. 1.0 Summary of Year 1 Monitoring 1 2.0 Introduction ....................................................................................................... 1 ........................................................................................ 2.1 Project Information 2 ....................................................................................... 2.2 The As-built Project 2 ........................................................................................ 3.0 Monitoring Methodology 3 ..................................................................................... 3.1 Final Success Criteria 3 ....................................................................................... 4.0 Year 1 Monitoring Results 3 ................................................................................ 4.1 Standard Success Criteria 3 .................................................................................. 4.2 Function-Based Criteria 4 .................................................................................. 4.3 General Site Conditions 5 ................................................................................................. 5.0 Recommendations 5 ....................................................................... 5.1 Year 2 Supplemental Irrigation 6 .......................................................................... ................. 5.2 Year 2 Weeding 1. 6 ............................................................ ............................. Figure 1 . Regional Map , 8 .............................................................................................. . Figure 2 Revegetation Map 9 ................................................................. . Photograph Comparison Installation to Present 10 .............................................................................. Photographs of Transects - March 2011 11 ................................................................ Plant Species Occurring in Belt Transects 1 and 2 12 15BFARAD.\Y (7Wj AVENUE 911m XliTE FAY IIU (7UV 911-5:44 C2UUSAAD . Ch9W April 13. 2011 # 081119
Annual Mitigation Monitoring Report for 2010 Calavera Creek Channel Protection Project Carlsbad, California April 13,20 1 1 1.0 Summary of Year 1 Monitoring The Calavera Creek Channel Protection revegetation project is a 0.162 acre southern willow scrub creation plot that is revegetation mitigation for non-wetland waters project related impacts. The revegetation is located in the Calavera Creek flood plane of upstream of the improvements project site in Carlsbad, CA. The approved mitigation program calls for a minimum of five years of monitoring and maintenance to be provided by the project proponent. Year two riparian scnib growth and establishment of the plot is very good. Based on quantitative monitoring, the revegetation has met all of its function-based performance criteria, and also its standard success criteria for a two year old installation. The native wetland cover was an outstanding 89% absolute cover, composed of tree, shrub, and ground cover layers. Several wetland indicators were observed on the revegetation plot, including scouring, deposition of sandy material, algal mat formation, emergent species natural recruitment, and obligate wetland plant species presence. Year two maintenance will focus on irrigation delivery and weed control. Supplemental irrigation was utilized to assist the project in years one and two establishment. For year three, irrigation will be withheld to the extent possible so that the establishing plants acclimate to the natural hydrologic regime of the site. Irrigations will be restricted to the amount necessary to keep riparian scrub species from significant damage or death. The primary maintenance activity during the coming year is aggressive weed control. 2.0 Introduction Monitoring Report 2 describes the status of revegetation to mitigate for impacts to jurisdictional waters as described in, Calavera Creek Channel Protection Proiect Jurisdictional Waters Impacts Mitigation Program for the Citv of Carlsbad Bridge & Thoroughfare District No. 4. Carlsbad. California. The project is the result of rainstorm induced erosion damage to stream bank located along Calavera Creek near the confluence with Little Encina Creek. To remediate this damage, the project applicant agreed to provide the City of Carlsbad Bridge & Thoroughfare District No. 4, the following work: 1. Repair erosion damage to a portion of Calavera Creek by installing gunite and rip rap, 2. Creek bank plant restoration of 0.08 acre of temporarily impacted stream channel, and 3. Creation of 0.162 acre of Corps jurisdictional wetlands adjacent to an existing 8.3 acre wetland creation site located in basin BJB near the Cannon RoadICollege Boulevard intersection. Items 1 and 2 have been completed. The subject of this report is Item no. 3, the creation of 0.162 acre of southern willow scrub revegetation. The installation phase of this project was certified complete by Planning Systems' restoration ecologist on February 5,2009. A Post-project Mitigation Implementation Memo was issued on April 1,2009 and provided to USACE, CDFG, RWQCB, and City of Carlsbad, which stated that the revegetation was installed per the approved plans. This revegetation has now been installed for approximately two years. Monitoring data for this report was collected on March 16,201 1. Calavera Creek Channel Protection Project Revegetation Monitoring Report for 2010 1
2.1 Project Information Permit1 Authority - U.S. Army Corps of Engineers Nationwide Permit Authorization No. 200500957-KJC - CA RWQCB Clean Water Act section 401 Water Quality Certification No. 05C-063 Mitigation Program This report is provided in partial satisfaction of revegetation implementation requirements described in Calavera Creek Channel Protection Proiect Jurisdictional Waters Impacts Miti~ation Program for the Citv of Carlsbad Bridae & Thoroughfare District No. 4. Carlsbad, California, by Planning Systems, July 5,2007. Ownership Brookfield Homes 12865 Pointe Del Mar, suite 200 Del Mar, CA 92014-3859 Mitigation Required Creation of 0.162 acre of southern willow scrub that is Corps jurisdictional wetlands. The mitigation site is adjacent to an existing 8.3 acre wetland creation site located in basin BJ near the Cannon RoadICollege Boulevard intersection (figure 1). Installation Date The revegetation installation began on 10-3 1-08 and the installation was completed on 2-5-09. Irrigation Shut-off Date Supplemental irrigation was utilized during 2009 and 2010, and is anticipated to be used as needed during 201 1. The target date for the cessation of supplemental irrigation is anticipated to be no later than February 5,20 12. 2.2 The As-Built Project The project was initially installed per the approved plans. As per the Program, plot grading was not required to change site hydrology; however, a channel was grooved into the plot to direct seasonal storm water flow through the plot. Irrigation was installed and non-native grasslands were herbicided during three grow and kill cycles (existing desirable wetland plants were protected in place). Container plants were installed, and then seed was sown and scratched into the soil. The plot was installed adjacent to the existing Calavera Hills Phase 11 Wetland Restoration Project in a floodplain of Calavera Creek known as Basin BJ, northwest of the College Blvd/ Cannon Road intersection in Carlsbad. A minor adjustment in plot configuration and location was made to insure that a common boundary is shared with the Calavera Hills Phase 11 Wetland Restoration Project (figure 2). To assist underperforming areas, a remedial planting was installed on July 2,2009. Species from the approved planting list and two additional southern willow scrub species observed establishing in the adjacent Calavera Hills Phase 2 Mitigation Area were installed. The additional species were Rosa californica, and Juncus arcticus var. mexicanus. Calavera Creek ChanneI Protection Project Revegetation Monitoring Report for 2010
3.0 Monitoring Methodology As per the approved mitigation plan, the revegetation will be monitored both qualitatively and quantitatively. Qualitative monitoring will include function-based assessments, wildlife observations, plant list including weeds, and a general site assessment. Quantitative monitoring will be measure revegetation development using protocols of the California Native Plant Society Plant Communities Project (Sawyer and Keeler-Wolf 1995). 3.1 Final Success Criteria I) The mitigation area will be monitored for at least five years and include 5 annual reports. 2) The mitigation sites will be assessed using two methods; standard success criteria and the functional evaluation accepted by the U.S. Army Corps of Engineers (Stein 1999). 3) General site conditions such as wildlife use, diversity of native wetland plants, resilience, and presence of wetland indicators will be evaluated. 4) All wetland types to be created, restored, or enhanced shall meet the three-parameter wetlands criteria that include hydrophytes, hydric soils, and natural hydrology. 5) Evidence of natural recruitment of milltiple species at the end of five years. 6) 0% coverage for Cal-IPC7s "lnvasive Plant Inventory" species at the end of 5 years 7) No more than 10% coverage for other exoticlweed species at the end of five years. 4.0 Year 2 Monitoring Results Monitoring results for year 2 are provided below. Assessment criteria for this report includes: I) monitoring using standard success criteria, 2) monitoring using function-based criteria, and 3) reporting on general site conditions. 4.1 Standard Success Criteria Standard success criteria are used to assess the quality and composition of the vegetation being grown. Quantitative data was collected on March 16,201 1, using (2) twenty-five meter x 5 meter belts. Transect measurements indicate that 12 native species were "hit" over the 100 transect b'points" measured: two tree species, two shrub species, and eight ground cover species. Within the 5 meter wide belt, six additional native species were observed. Five weed species were recorded as transect measured "hits", and two other weed species were observed in the belt. In terms of cover, absolute wetland native cover of 89% was measured, 5% of weed cover was measured, and 6% bare ground was measured. All three of these categories indicate improvement over year on monitoring data. At 89% native cover the plot has grown over 10% move native cover during the past year. The 5% weed cover meets the target project weed cover percentage and indicates 3.5% less weed cover than year one. Six percent bare soil is acceptable for year two growth. Table 2 below summarizes transect measurement results. Calavera Creek Channel Protection Project Revegetation Monitoring Report for 2010