DRAFT Chacon Creek, Laredo, Texas Biological Assessment April 2018 Prepared by: Tetra Tech, Inc. 6121 Indian School Rd. NE, Suite 205 Albuquerque, New Mexico 87110 Laredo, Texas April 2018 Table of Contents 1 - Introduction ............................................................................................................................. 1 1.1 Federal Action and Authority ........................................................................................... 1 1.2 Project History.................................................................................................................. 2 2 - Location and Site Description ................................................................................................ 2 2.1 Description of the Action Area and Project Sites ............................................................ 2 2.2 Study Setting .................................................................................................................... 6 3 - Biology and Distribution of Listed Species............................................................................ 7 3.1 Federally-Listed Species and Critical Habitat .................................................................. 7 3.2 Status of the Species within the Action Area ................................................................... 9 Ocelot ...................................................................................................................................... 9 Gulf Coast Jaguarundi........................................................................................................... 14 Texas Hornshell .................................................................................................................... 17 4 - Description of the Proposed Action ..................................................................................... 19 4.1 Proposed Action ............................................................................................................. 19 4.1.1 Flood Risk Management .............................................................................................. 19 4.1.2 Ecosystem Restoration ................................................................................................. 20 4.1.3 Recreation .................................................................................................................... 20 4.2 Best Management Practices (BMPs) .............................................................................. 21 Species Specific BMPs for the ocelot and jaguarundi: ......................................................... 22 4.3 Ecosystem Restoration Measures ................................................................................... 22 4.4 Maintenance Activities ................................................................................................... 23 Flood Risk Management ....................................................................................................... 23 Ecosystem Restoration .......................................................................................................... 23 Recreation ............................................................................................................................. 23 4.5 Monitoring during Implementation of the Proposed Action .......................................... 23 During Construction.............................................................................................................. 24 Post-Construction .................................................................................................................. 24 5 - Effects of the Proposed Action ............................................................................................. 24 5.1 Direct Effects.................................................................................................................. 25 Vegetation Removal/Mowing ............................................................................................... 25 Temporary Noise from Construction Activities ................................................................... 25 Chacon Creek, Laredo, Texas Biological Assessment i Laredo, Texas April 2018 5.2 Indirect Effects ............................................................................................................... 26 5.3 Cumulative Effects ......................................................................................................... 26 Vegetation ............................................................................................................................. 26 Wildlife ................................................................................................................................. 27 Threatened and Endangered Species .................................................................................... 27 Recreation ............................................................................................................................. 27 Aquatic .................................................................................................................................. 28 Water Quality ........................................................................................................................ 28 5.4 Effects Determination .................................................................................................... 28 6 - References and Personal Communications Cited ............................................................... 30 7 - Appendices ............................................................................................................................. 37 7.1 Appendix A. Federally threatened, endangered and proposed to be listed species list in proposed project location, 02ETTX00-2018-SLI-0394 ............................................................ 38 7.2 Appendix B. Custom Soil Resource Report for Webb County, TX .............................. 39 7.3 Appendix C. Chacon Creek Monitoring and Adaptive Management Plan ........................ 40 List of Figures Figure 1. Study Location................................................................................................................. 3 Figure 2. Study Location Reaches .................................................................................................. 5 List of Tables Table 1. Threatened, Endangered and Candidate Species in Study Area ....................................... 8 Chacon Creek, Laredo, Texas Biological Assessment ii April 2018 1 - Introduction The U.S. Army Corps of Engineers (USACE), Fort Worth District in partnership with the City of Laredo (City) as the non-federal sponsor completed the Chacon Creek, Laredo, Texas, Draft Feasibility Study and Environmental Assessment (Study) in 2007 and updated the Study in 2018, which evaluated ecosystem restoration needs and opportunities for Chacon Creek. The purpose of the Study was to identify potential measures that could reduce the risk of flooding, restore degraded aquatic ecosystems, and provide increased recreational opportunities. These measures include, but are not limited to, three primary objectives: • Flood risk management measures that would reduce the risk of future damages along Chacon Creek • Ecosystem restoration measures that would restore degraded aquatic and riparian habitat and increase ecosystem function to a more natural condition • Increased recreational amenities that would integrate and compliment ecosystem restoration 1.1 Federal Action and Authority Section 7(a) (2) of the Endangered Species Act (ESA) of 1973 assures that, through consultation with USFWS, federal actions “…are not likely to jeopardize the continued existence of any federally proposed or listed endangered species or threatened species, or result in the destruction or adverse modification of critical habitat of such species…”. The purpose of this Biological Assessment (BA) is to comply with this requirement and assess potential actions outlined in the Study on proposed or listed ESA species within the project action area. There are an estimated 503 structures located in the Chacon Creek 500-year floodplain that are at risk of flooding in Laredo, Webb County, Texas. Urban growth and other watershed perturbations, such as increased imperviousness, have altered flow regimes leading to exacerbated flooding along Chacon Creek during high rainfall events. Flood events in 2002 prompted the city to permanently evacuate three houses along Chacon Creek. Flooding in 2007 impacted the City and resulted in extensive property damage and the first flooding death in Laredo’s history. Laredo received five to eight inches of rain in a four-hour period during 2007 flooding events, whereas average annual precipitation is 20 inches. Eighteen homes were reported to have received major damage, and an additional 50 homes received varied damages. Rapid urbanization within the watershed and associated changes in storm runoff timing and volumes into Chacon Creek have also caused hydrogeomorphological effects including erosion and loss of wetland habitats and vegetation. The stream provides flood conveyance, but it also serves as a local natural resource with considerable recreational, educational, and economic potential. The city also has a sizable deficiency in terms of the number and size of its park facilities, particularly passive recreation amenities such as trails, pavilions and shelters, picnic tables, and playgrounds. 1