Carp on a mission to devour canal weeds

April 25, 2002|By LAURA MITCHELL

Staff Writer

The Bard Water District is using 300 weed-eating carp to clean canals that are getting heavy with weeds.

"If we can't keep this canal clean, we can't deliver water to our customers," Bard Water District manager Ron Derma said.

The weeds act like a giant sponge and can cause ditch breaks and clogs in canals, Derma said.

Releasing the carp now can help during the hot summer months when the weeds grow the fastest, he said.

U.S. Bureau of Reclamation engineer Frank Macaluso Jr. compared the carp to goats on a farm eating stubble.

Derma said this is the first time the carp have been released into Bard's canals. The water district is hoping the fish will solve problems that occur when canals are manually cleaned.

The canals are cleaned five or six times a year using a drag chain like a giant net to pull out the weeds. Dragging interrupts the water supply and costs $5,000 for each cleaning, he said.


The district also kills weeds by letting canals run dry when farmers are not using the water, Derma said. The district normally schedules five or six dry-ups a year on the water system.

The Bard Water District bought the fish from the Imperial Irrigation District, which also uses grass carp to clean canals.

The grass carp can consume their body weight in a day and can weigh 40 or 50 pounds. The carp released into canals are all sterile to ensure they don't reproduce, Imperial Irrigation District spokeswoman Susan Giller said.

IID operates the only sterile grass carp hatchery in California, Giller said.

Water weeds are a major problem in the Imperial Valley because the weeds love heat and they love the sun, she said. Pesticides can't be used to clean the weeds because the water is used for growing crops.

Manual cleaning is costly and less effective so IID invested in the hatchery, Giller said.

The Bard Water District paid $15 a fish for the 300 sterile grass carp, she said.

"They're not cheap," Giller said.

At that cost, it's important to make sure the fish don't enter the Colorado River or end up as someone's dinner.

California Fish and Game fisheries biologist Martin Muschinske "scanned" each fish before it went into the canal.

The fish are electronically tagged so they can be traced if one shows up somewhere it's not supposed to, Muschinske said.

The fine for catching a sterile grass carp is $5,000, he said.

Muschinske said the water district is using an exclusion gate at the end of the canal to keep the fish from going into the Colorado River.

Derma said if fish got into the Colorado River, they could upset the ecosystem.

>> Staff Writer Laura Mitchell can be reached at 337-3452 or

Imperial Valley Press Online Articles