Reclamation Information Sharing Environment (RISE)

Nuisance aquatic vegetation growth may detrimentally impact water flow and water quality in delivery systems such as canals. A traditional method of control is the use of federally-approved aquatic herbicides which are commonly added to the water by slug or surface applications. However, these chemicals may not be as efficacious in flowing water systems due to a lack of real-time measurements of diluting concentrations and exposure time. The problem is further compounded when the flow rate in a water delivery system is fluctuating. Uncertainties in the applications of aquatic herbicides such as travel times, length and duration of slug or surface injections, and water delivery parameters cannot be easily determined since aquatic herbicides cannot be detected in real time. This project was successful in demonstrating the capability of improving precision of aquatic herbicide applications in canals that are impacted by nuisance aquatic vegetation (NAV). A fluorescent dye (Rhodamine WT) was successfully used as a surrogate which can be monitored in real time with the use of in-situ fluorescence detectors. Co-injection of aquatic herbicides and dyes may help alleviate uncertainties of aquatic herbicides applications to improve water delivery.