Lower Colorado River Watershed Management Plan
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Lower Colorado River Watershed Management Plan Lower Colorado River Watershed Management Plan Prepared for Clean Colorado River Sustainability Coalition 2330 McCulloch Blvd N Lake Havasu City, Arizona 86403 Attn: Doyle Wilson Prepared by SWCA Environmental Consultants 114 North San Francisco Street, Suite 100 Flagstaff, Arizona 86001 (928)774-5500 www.swca.com SWCA Project No. 40291 September 2018 Lower Colorado River Watershed Management Plan i Lower Colorado River Watershed Management Plan Executive Summary The Lower Colorado River (LCR) Watershed includes the Havasu-Mohave Lakes and Imperial Reservoir hydrologic units that cover nearly 8,639 square miles of land south of Hoover Dam along the Colorado River mainstem in Arizona, California, and Nevada. In the planning area, highly regulated releases from Hoover Dam largely control the flow of the river for 260 miles south towards the United States–Mexico border. Several tributaries have the potential to affect water quality negatively in the LCR due to stormwater pollution runoff. Drought, invasive species, and land development are also possible influences to water quality degradation. Designated uses for the LCR include agriculture (irrigation and livestock watering), full- and partial-body-contact recreation, domestic water supply, fish consumption, and aquatic life and wildlife. Land use consists primarily of barren land followed by agriculture and widely separated urban development. The Watershed Management Plan (WMP) for the Lower Colorado River was written as part of the WaterSMART grant through the U.S. Bureau of Reclamation to expand and diversify membership for the Clean Colorado River Sustainability Coalition (CCRSCo) and develop this watershed management plan. The WMP reflects the goals and objectives identified through a stakeholder driven process, involving landowners, municipalities, Tribes, Townships, and Counties to improve and protect water quality in the Lower Colorado River from various pollutant sources. The goals and objectives of this plan were derived from community stakeholder meetings, public participation, and CCRSCo to address negative impacts to water quality in the planning area. Issues were narrowed down and prioritized, by CCRSCo and various stakeholders, to determine suspected sources and causes of pollution. Information was obtained and analyzed through aerial photographs, topographic maps, plat maps, soil surveys, biological assessments, and reports administered by various state and federal agencies, Tribes, and non- governmental organizations, historical research, and discussions with landowners throughout the watershed. Reducing point and non-point sources of pollution, analyzing future drought effects, eradicating non- native species, and investigating future land development will improve water quality in the LCR through goals described in this WMP. The goals and objectives of this WMP will be accomplished by implementing appropriate best management practices on critical sites and areas, and providing information and education to residents, landowners, Tribes, Townships, and Counties to protect open space, natural floodplains, and water quality health through effective and efficient land use planning and conservation. The primary elements of this WMP include: • Stakeholder participation • Baseline data analysis and summary • Watershed assessment • Watershed management activity recommendations. i Lower Colorado River Watershed Management Plan ii Lower Colorado River Watershed Management Plan Acronyms and Abbreviations % percent °C degrees Celsius °F degrees Fahrenheit μg/L microgram per liter ADEQ Arizona Department of Environmental Quality ADWR Arizona Department of Water Resources AGFD Arizona Game and Fish Department AZ Arizona BIA Bureau of Indian Affairs BLM Bureau of Land Management BMP best management practices CA California CaCO3 calcium carbonate CAFO Concentrated Animal Feeding Operations CAP Central Arizona Project CCRA Clean Colorado River Alliance CCRSCo Clean Colorado River Sustainability Coalition CCRWUP California’s Colorado River Water Use Plan CDBW California Department of Boating and Waterways CDTSC California Department of Toxic Substances Control CDWR California Department of Water Resources CERCLA Comprehensive Environmental Response, Compensation, and Liability Act Coalition Colorado River Regional Sewer Coalition CSWRCB California State Water Resources Control Board CWA Clean Water Act DDE Dichlorodiphenyldichloroethylene DEO U.S. Department of Energy DNR Department of Natural Resources DOI U.S. Department of the Interior DPP Drought Preparedness Plans EA environmental assessment EDC endocrine-disrupting compound EIS environmental impact statement EPA U.S. Environmental Protection Agency ESA Endangered Species Act FIFRA Federal Insecticide, Fungicide, and Rodenticide Act HACCP-NRM Hazard Analysis and Critical Control Point – Natural Resource Management HUC Hydrologic Unit Code I- Interstate IBI Index of Biological Integrity IBWC International Boundary and Water Commission IDD Irrigation and Drainage District kWh kilowatt-hours LCR Lower Colorado River LCR MSCP Lower Colorado River Multi-Species Conservation Program iii Lower Colorado River Watershed Management Plan LCRWQP Lower Colorado River Water Quality Partnership LDCA Laguna Division Conservation Area LUST leaking underground storage tanks M&I municipal and industrial MCL maximum contaminant level mg/L milligrams per liter MHV Lake Mohave groundwater basin mL milliliters mL/L milliliters per liter MWD Metropolitan Water District of Southern California N/A not applicable NDEP Nevada Division of Environmental Protection NGO non-governmental organization NHDES New Hampshire Department of Environmental Services NPDES National Pollutant Discharge Elimination System NPS National Park Service NPSWRD National Park Service Water Resources Division NRA National Recreation Area NRCS Natural Resources Conservation Service NTU Nephelometric Turbidity Unit NV Nevada NWR Imperial National Wildlife Refuge PBT Persistent Bioaccumulative Toxic PCP personal care product PEC pharmaceuticals and other emerging contaminants PG&E Pacific Gas and Electric planning area Imperial National Wildlife Refuge ppb parts per billion PPCP pharmaceuticals and personal care product RCRA Resource Conservation and Recovery Act Reclamation U.S. Bureau of Reclamation RV recreational vehicle SWP System Water Plans TDS total dissolved solids TMDL total maximum daily load TSS total suspended sediments UCANR University of California Agriculture and Natural Resources U.S. United States USDA U.S. Department of Agriculture USFWS U.S. Fish and Wildlife Service USGS U.S. Geological Survey UST underground storage tank VOC volatile organic compound WCP Water Conservation Plans WMP Watershed Management Plan WQARF Water Quality Assurance Revolving Fund WUR Water Use Reports WWTP wastewater treatment plant YPG Yuma Proving Ground iv Lower Colorado River Watershed Management Plan CONTENTS Executive Summary ..................................................................................................................................... i Acronyms and Abbreviations ................................................................................................................... iii Project Partners and Acknowledgements .............................................................................................. ix Chapter 1 Introduction .......................................................................................................................... 1 1.1 Document Overview .................................................................................................................. 1 1.2 Planning Purpose and Process ................................................................................................... 1 1.3 Watershed Management Team .................................................................................................. 4 1.3.1 Public Participation Approach .................................................................................. 4 1.4 Document Organization ............................................................................................................ 6 Chapter 2 Watershed Description ........................................................................................................ 7 2.1 Physical and Natural Features ................................................................................................... 8 2.1.1 Watershed Boundaries and Tributaries ..................................................................... 8 2.1.2 Physical Description ............................................................................................... 11 2.1.3 Topography/Elevation Data .................................................................................... 23 2.2 Biological Resources ............................................................................................................... 24 2.2.1 Vegetation ............................................................................................................... 24 2.2.2 Wildlife ................................................................................................................... 25 2.3 Land Use and Land Cover ....................................................................................................... 30 2.3.1 Open Space ............................................................................................................. 32 2.3.2 Agriculture