Goal 1: Protect, Maintain and Improve Water Quality
Photos here
Current Status and Issues of Concern
Based on feedback from community meetings, stakeholder interviews, and questionnaires, two issues top
the list of natural resource concerns in the Colusa Basin Watershed: water quality and water supply. This
is not surprising given the watershed’s geographical location and the agriculturally-based economies that
dominate the watershed. A healthy and abundant water supply is essential for human health, crop and
livestock production and healthy natural resources. The following list outlines the major water quality
concerns in the Colusa Basin Watershed as identified by stakeholders, the Colusa Basin Watershed
Assessment, and other related reports:
Sediment: Seasonal flood flows cause land and channel erosion and disturbed channel beds, which lead
to high levels of turbidity in waterways.
Stormwater runoff: Runoff carries contaminants and sediment to waterways.
Salinity: Salinity can occur when water supply is lacking. Threats to our future water supplies increase
the likelihood of high salinity levels.
Pesticide and chemical discharge: Runoff from agricultural land and urban landscapes carry pesticides
and chemicals to waterways.
Dissolved Oxygen (D.O.): Low flows and stagnant water lead to increased water temperatures and low
percentages of D.O. Adequate D.O. is necessary for healthy aquatic systems.
Nitrates: High levels of nitrogen in water can cause oxygen depletion, affecting survival of aquatic insects
and fish, and degrading water quality.
Supply: Too much water causes flooding and stormwater runoff while too little water can cause water
quality issues that include salinity, low D.O. and concentrated levels of pesticides and chemicals.
Water quality issues in the upper watershed are primarily a result of erosion and sedimentation. Water
quality in the valley and lower watershed is affected by agricultural field drainage and reuse of irrigation
water. The majority of irrigation water is supplied to the Colusa Basin Watershed primarily by a variety
of water suppliers who pump from the Sacramento River. This water is considered of excellent quality
(CH2MHill 2003). Both drainage and reuse, however, cause increases in salt and sediment loading and in
some cases, pesticide and fertilizer impacts. Municipal wastewater treatment plant discharge and
stormwater discharge from Willows, Williams, Maxwell, Dunnigan, and Colusa also contribute to
degradation of water quality (Harvey et. al 2008).
The Central Valley Regional Water Quality Control Board has adopted regulatory requirements for
discharges from irrigated lands (tailwater, water from underground drains, stormwater runoff) to waters
of the State under a Conditional Waiver of Waste Discharge Requirements. The Irrigated Lands
Regulatory Program (ILRP) regulates such discharges located within the jurisdiction of the Central Valley
Water Board, which extends from the Oregon border south to the northernmost tip of Los Angeles County
(Region 5). Water quality coalitions have been formed throughout the Central Valley in response to the
Conditional Waiver. Under those coalitions, local Subwatershed groups have formed to coordinate the
program at the local level. These Subwatershed groups coordinate water quality monitoring and
reporting and also provide education and outreach to promote practices that improve water quality in
discharge from irrigated lands. In the Colusa Basin Watershed, the Colusa Glenn Subwatershed Program
and the California Rice Commission work at the local level to meet the requirements of the ILRP.
Considerations
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Focus on multi-use and multi-benefit solutions
Outreach, education and community awareness are necessary elements in protecting water
quality
Groundwater and surface water quality are equally important
Best Management Practices (BMPs) should be encouraged
Many regulatory issues exist in the realm of water quality
Objectives and Actions
Objective #1: Identify Water Quality Issues
Action
Coordinate with the local Subwatershed Programs
to remain aware of sources of water quality
impairments
Evaluate current conditions and identify methods
of improvement
Entities involved
 RCDs
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RCDs
Subwatershed groups
Objective #2: Recommend water quality improvement measures for urban and rural areas
Action
Entities involved
Work with City and County Agencies
 RCDs
Support flood control programs
 RCDs
 Local governments
Support multi-benefit solutions
 RCDs
Objective #3: Provide community awareness of causes of water quality impairment
Action
Entities involved
Provide outreach and Education
 RCDs
Create a Community Awareness Campaign
 RCDs
Promote voluntary actions to prevent pollution
 RCDs
from such sources as: fertilizers, pesticides, motor
oil, illegal dumping, soil erosion, hazardous waste,
etc.
Objective #4: Encourage and implement measures to protect groundwater from contaminants
Action
Entities involved
Support implementation and updates of County
 RCDs
groundwater Management Plans
 Boards of Supervisors
Avoid groundwater overdraft
 Groundwater users
Promote utilization of surface water supplies
Improve groundwater infiltration and protect
existing recharge areas
Encourage proper sealing of abandoned wells
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Local water authorities
RCDs
NRCS
Landowners and land managers
Local Departments of Environmental
Health
Objective #5: Recommend Best Management Practices (BMPs) for agricultural and rangeland areas
to reduce soil erosion and associated sediment loading into drainages
Action
Entities involved
Promote erosion control efforts
 RCDs
Encourage and assist in implementation of BMPs,
 RCDs
including filter strips, grassed waterways, off NRCS
stream grazing, etc.
Where feasible, restore flood plain connectivity
 RCDs
along streams
 NRCS
 Other conservation organizations
 Landowners and land managers
Objective #6: Provide technical advice for implementing BMPs
Action
Entities involved
Work with NRCS to provide local outreach
 RCDs
regarding Farm Bill programs
Resources
The following resources are available for information and technical assistance:
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California State Water Resources Control Board
http://www.swrcb.ca.gov/
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California Department of Water Resources
http://www.water.ca.gov/
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Colusa Glenn Subwatershed Program
530.934.4601, ext. 120
email: cgsubwatershed@sbcglobal.net
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Natural Resources Conservation Service
Colusa County
100 Sunrise Blvd., Suite B, Colusa CA 95932
530.458.2931
Glenn County
132 North Enright Avenue, Suite C, Willow, CA 95988
530.934.4601 X3
Yolo County
221 W. Court Street, Woodland, CA 95695
530.662.2037
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Resource Conservation Districts
Colusa County
100 Sunrise Blvd., Suite B, Colusa, CA 95932
530.458.2931 X3
www.colusarcd.org
Glenn County
132 North Enright Avenue, Suite C, Willow, CA 95988
530.934.4601 X5
www.glenncountyrcd.org
Yolo County
221 W. Court Street, Woodland, CA 95695
530.662.2037
www.yolorcd.org
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U.C. Davis California Rangeland Watershed Laboratory
www.rangelandwatersheds.ucdavis.edu
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County Departments of Environmental Health
Colusa County
Glenn County
Yolo County