Watershed Protection Plan - Lower Rio Grande Valley Development ...

CONTENTS
ACKNOWLEDGEMENTS .......................................... vii
EXECUTIVE SUMMARY ..............................................1
The Arroyo Colorado Watershed (ACW) Partnership .....2
State of the Watershed ...................................................2
Habitat ......................................................................3
Water Quality ............................................................4
Wastewater Infrastructure ........................................4
Agriculture ................................................................4
Storm Water Management .......................................5
Education and Outreach ...........................................5
Sources and Causes of Pollution ....................................6
Institutional Framework ...................................................6
Elements of the Watershed Protection Plan ...................7
Monitoring and Measuring Progress ...............................7
Watershed-scale Water Quality Monitoring ...........8
Wastewater Effl uent Monitoring ............................8
Project Specifi c Monitoring ....................................8
INTRODUCTION ...........................................................10
Watersheds ...................................................................12
Watershed Stewardship ................................................13
THE ARROYO COLORADO
WATERSHED PARTNERSHIP .................................15
Organizational Structure ...............................................15
Steering Committee ................................................15
Work Groups ..........................................................15
Mission ..........................................................................18
Vision ............................................................................18
Goals.............................................................................18
Background ...................................................................19
Supporting Documents ...........................................20
THE ARROYO COLORADO WATERSHED ........................22
Arroyo Colorado Watershed Characteristics .................22
Water Body and Watershed Description ................23
Topography .............................................................24
Geology and Soils ..................................................24
Climate and Rainfall ...............................................26
Demographics, Socio-Economics,
and Growth ..........................................................26
History of Human Activity .......................................28
STATE OF THE WATERSHED ............................................33
Habitat...........................................................................33
Water Quality ................................................................37
Dissolved Oxygen...................................................40
Biochemical Oxygen Demand ................................41
Nitrogen ..................................................................42
Phosphorus ............................................................43
Chlorophyll-a ..........................................................44
Sediment ................................................................45
Fecal Bacteria.........................................................46
Legacy Pollutants ...................................................46
Wastewater Infrastructure .............................................47
Municipal ................................................................48
On-Site Wastewater Systems and Colonias ...........49
Reuse of Wastewater .............................................49
Agriculture .....................................................................49
Urban Development ......................................................50
Flooding and Flood Control...........................................51
Storm Water Quality Management ................................51
Awareness of Water Quality Issues ..............................52
SOURCES AND CAUSES OF POLLUTION IN
THE ARROYO COLORADO .....................................56
Wastewater ...................................................................56
Colonias ........................................................................57
Agriculture .....................................................................58
Urban Storm Water .......................................................59
Industrial Activity ...........................................................60
The Role of Physical Modifi cations ...............................60
INSTITUTIONAL FRAMEWORK .............................64
Federal Agencies and Programs ..................................64
U.S. Army Corps of Engineers (USACE)................64
U.S. Department of Agriculture (USDA) .................64
U.S. Environmental Protection
Agency (USEPA) .................................................65
Federal Emergency Management
Administration (FEMA) ........................................65
U.S. Fish and Wildlife Service (USFWS)................65
U.S. Geological Survey (USGS).............................65
U.S. International Boundary and Water
Commission (IBWC)............................................66
National Oceanic and Atmospheric
Administration (NOAA)........................................66
January 2007 i Arroyo Colorado Watershed Protection Plan