Surface Water Quality
Attention to the impacts of irrigated agricultural practices on water quality in public waterways of California has heightened over the past 15 to 20 years and in particular during the last four years. In 2003, a Conditional Waiver for discharges of storm water and irrigation runoff from irrigated lands was first adopted by the Central Valley Regional Water Quality Control Board and has, since, resulted in increased monitoring of watercourses that are in predominantly agricultural areas but eventually contribute to public watercourses further down gradient. There is also a growing interest in adoption of farm management practices that continue to protect water quality or improve water quality where there is evidence that a water body has been impaired by irrigated farming practices.In response, UC Cooperative Extension has strived to help landowners and operators stay current on the status of the Conditional Waiver and to contribute applied research. The applied research has focused on: 1) farm management aspects; and 2) policy aspects.
Status of Central Valley Conditional Waiver
Formation of Coalition Groups
One outcome of the Conditional Waiver as originally adopted by the Regional Board in 2003 and then when renewed in 2006 is the formation of Coalition Groups. Coalitions are organized groups of landowners and operators of irrigated lands throughout different areas of the Central Valley with uniquely different farm settings and hydrologic conditions. Landowners and operators within these different Coalitions work together to comply with the Conditional Waiver by conducting their own, but Regional Board approved, surface water quality monitoring and work together to respond to water quality concerns identified by the monitoring program and clearly associated with irrigated farming practices. Coalitions address surface water quality issues from a watershed perspective rather than on an individual farm basis. Many view this approach as an efficient and effective way of implementing a water quality management program for the agricultural industry in the Central Valley.
Currently, their are nine Coalition Groups throughout the Central Valley of California ranging from Kern County in the south to the Oregon Boarder in the north. A fact sheet giving background about the Conditional Waiver, a copy of the Conditional Waiver for Coalition Groups, and a list of the Coalition contacts throughout the Central Valley is provided below:
Fact Sheet-Conditional Waiver for Irrigated Lands
Conditional Waiver for Coalition Groups, adopted August 2006
List of Coalitions and Contact Information for Central Valley
List of Local Coalition Groups in the Sacramento Valley
Joining a Coalition
The voluntary formation of Coalitions throughout the Central Valley has been underway since January 2003. In August 2006, the Regional Board adopted a deadline of December 31, 2006 for irrigated landowners to join the appropriate Coalition(s) directly. Since April 2008, irrigated landowners desiring coverage as a Coalition member have limited opportunities to join and new membership requires approval by the Regional Board. More information and an application form to join a Coalition are available below:
APPLICATION FOR NEW MEMBERSHIOP INTO A COALITION
Sacramento Valley Water Quality Coalition (SVWQC)
The SVWQC is one of the nine Coalitions in the Central Valley and it seeks to provide a vehicle for irrigated landowners and operators in the Sacramento Valley to comply with the Conditional Waiver and protect and enhance surface water quality. The SVWQC employs a "nested watershed" approach to manage and protect water quality, where the Sacramento Valley is divided into eleven sub watersheds each with unique agricultural settings and hydrologic conditions. Each sub watershed is founded on local agricultural leadership through an assortment of private and public entities such as County Farm Bureaus, local watershed groups, County Agricultural Commissioners, Resource Conservation Districts, and with support from UC Cooperative Extension. Oversight of the larger Sacramento Valley Water Quality Coalition is administered by the Northern California Water Association. A list of contacts for the eleven sub watersheds in the Sacramento Valley is provided below:
SVWQC Subwatershed Contacts
Shasta-Tehama Water Education Coalition (STWEC)
The STWEC is one of the eleven sub watersheds making up the Sacramento Valley Water Quality Coalition and assisting with implementing this agricultural water quality management program. STWEC currently provides waiver coverage to 1,602 landowners and an operator in southern Shasta and Tehama Counties who discharge or could potentially discharge storm water or irrigation runoff into public water ways and encompasses 75,460 irrigated acres.
The STWEC is headquartered in Cottonwood, California and administration of sub watershed activities and communication is undertaken by the Cottonwood Creek Watershed Group. Contact information and past newsletters are available below:
Shasta-Tehama Water Education Coalition
P.O. Box 158
Whitmore, CA 96096
STWEC Newsletter, January-June 2007
Applied Research Activity
The University of California Cooperative Extension in cooperation with UC faculty conduct research on different facets of the irrigated agricultural water quality issue. Some of the research has focused on farm management aspects and other research has studied policy aspects.
Farm Management Aspects
During 2006, a collaborative study involving UC Berkeley faculty and UC Cooperative Extension was conducted to evaluate and demonstrate the effectiveness of three management practices to reduce suspended sediments in irrigation runoff and insecticides bound to them. The study will be modified to some extent and repeated in 2007. The three management practices evaluated in 2006 included:
- Vegetated tailwater ditches to filter sediments from runoff as it leaves the field;
- Sediment basins to allow sediments to settle out of runoff as it leaves the field; and
- Polyacrylamide (PAM), an amendment added to the irrigation water before it is applied to the production field to reduce field erosion and suspended sediments in runoff.
This study focused on row and vegetable crop production with specific interest in managing suspended sediments and pyrethroids, a specific class of insecticides, that bind to the sediment. Pyrethroids are an important management tool in irrigated agriculture but are also a specific concern to sediment quality in stream and river channels. The research is being conducted on the CSU-Chico Farm, UC Davis Farm, and on a farm in the Salinas Valley. Findings from this study may also be of use to manage some nutrients and pathogens that also bind to suspended sediments.
After one year of evaluation, PAM and vegetated tailwater ditches appeared to be more effective at managing suspended sediments and pyrethroid insecticides bound to them than sediment traps. Reports and PowerPoint presentations are provided below:
2006 Technical Report- Management Practices for Mitigating off-site Transport of Soil-Absorbed Pesticides
Figures to Accompany 2006 Tehnical Report
Management Options to Reduce Pyrethroid in Tailwater from Row Crops-2007 Proceedings of the California Chapter American Society of Agronomy
PowerPoint - BMP's to Manage off-site Transport of Pyrethroid Insecticides, 2008 Nat'l Water Conference
PowerPoint - BMP's for Irrigation Runoff 2007, Chico Field Day
Policy Aspects of Water Quality
From 2003 through 2005, the University of California Cooperative Extension in collaboration with faculty at UC Davis conducted and completed a mail and telephone survey throughout the Sacramento Valley. It was a survey of producers' opinions about agricultural water quality management in the Sacramento River Valley.
Over 1200 producers from the Sacramento Valley responded to the survey, which coincided closely with the timing of the Central Valley Regional Water Quality Control Board's adoption of the Conditional Waiver for Irrigated Lands. The goal of the survey was to enhance the information available for forming agricultural water quality management policy. Hopefully, if policy makers better understand the opinions of producers they can enact more effective policy with lower costs, more benefits, and improved support and participation from the agricultural community. To read more about the survey findings refer to the report below:
Local Networks as Pathways to Sustainable Agriculture in the Sacramento River Valley, California Agriculture, Vol: 6, No. 3, Page 131
PowerPoint - Local Diffusion Networks, 2008 Nat'l Water Conference