Canal Milfoil Fight Beginning With Dewatering

Water levels are dropping in the Friant-Kern Canal, and troops, equipment and key tools are all in place as the Friant Water Authority launches its biggest fight yet in an attempt to control and hopefully eliminate a pesky aquatic weed, the Western water milfoil.

The dewatering process began as scheduled November 1, said Eric R. Quinley, FWA Maintenance Manager.

Unusually warm early November weather speeded dewatering in the canal’s lower reaches (south of Deer Creek in Tulare and Kern counties) with water demands that Operations Supervisor Gary C. Perez said were about four times the Friant-Kern Canal’s normal early November deliveries.


Quinley said full approval has been given by the state’s Departments of Public Health and Pesticide Regulation, and agricultural commissioners in Fresno, Tulare and Kern counties for applications of a pair of chemicals that will be used to rid the canal of the choking weed.

“All projects are predicted to hold to their schedules,” Quinley said. He said FWA equipment as well as rental equipment has been mobilized for not only the milfoil fight but many other non-related major maintenance and repair projects planned along the 152-mile canal.

The FWA will utilize its maintenance staff and has also hired 22 temporary workers.

Western water milfoil is an invasive perennial aquatic plant. It was detected in the canal 14 years ago in Fresno County. Past mechanical eradication and control efforts have been unsuccessful.

It grows rapidly and is generally submerged. Unfortunately, stems bearing reproductive structures not only reach above the surface but break, then being swept downstream to reproduce.


This winter’s dewatering was moved ahead one year because of mushrooming problems caused by milfoil, which has been spreading rapidly and diminishing the canal’s conveyance capacity as well as clogging turnouts and causing problems in distribution systems of districts and farmers.

The just-beginning dewatering process will be longer and more complex than usual because of the scope of work related to the milfoil battle. Canal deliveries are to resume by March 1.

Keys to getting the upper hand on the milfoil problem will be removal of silt from the canal prism – a favorite place for the weed to take root – and carefully timed applications of the chemical treatments that have been designed through a lengthy canal-side study process.

FWA officials stress that abundant safety precautions are being taken at every step.

Among the biggest project challenges have been assisting cities and towns that are municipal and industrial water contractors in making and implementing plans for alternative supplies. Those include Fresno, Orange Cove, Lindsay, Strathmore and Terra Bella.


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