Submitted to: Weed Science Society of California Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/28/2009
Publication Date: 6/10/2009
Citation: Macarthur, R.J., Rabidoux, A., Shvidehenko, A., Anderson, L.W., Cruey, B. 2009. Developing science-based strategies to manage water conveyance and control weed and sediment in irrigation and potable water supply canals. Proceedings of 61st Annual California Weed Science Society. p. 37-45. Interpretive Summary: Timely and adequate supplies of irrigation, potable and industrial use water are essential for successful agricultural production, domestic supplies (healthy water) and for a range of industrial uses. The Solano Irrigation District, which supplies multiple-use water is plagued with both nutrient/soil runoff loading as well as infestations of several non-native aquatic plants. This study documented the number, size and seasonal change in problematic aquatic plants as well as soil erosion sourced inputs. Better and more efficient “weed screens” need to be developed to reduce the chronic input of aquatic plants to the upstream end of the systems. Bank stabilization and weed management practices are being evaluated to determine the optimal and most cost-effective methods.
Technical Abstract: This paper describes on-going applied research, field monitoring, laboratory analyses and hydrologic investigations being conducted by Northwest Hydraulic Consultants (NHC) with the Solano County Water Agency (SCWA) in collaboration with USDA-ARS and Solano Project Operators to identify the sources and magnitude of sediment, turbidity and aquatic vegetation entering and affecting the Putah South Canal (PSC), located in Solano County, California. The presence and highly variable concentrations of these constituents in the PSC cause increasing canal maintenance and operational costs, and water quality problems for water users that rely on PSC water for their primary source of irrigation, municipal or industrial water supply. Types and distribution of aquatic plants were determined as well as the extent of plant propagule introduction from upstream “nursery” habitats. We found large numbers of viable fragments of various sizes were “imported” via downstream water movement from impounded and natural habitat sources. Potential sources of nutrient loading (e.g. runoff and bank-sloughing), coupled with assessments of current “weed” screening apparatus suggest that alternatives may provide a more sustainable and effective management strategy.