August 28, 1997 in Nation/World

It’s War On Muskrats In The Netherlands Prolific Pests Are Destroying Country’s Dikes With Their Incessant Digging

William J. Kole Associated Press
 

Across the lush lowland echoes a triumphant “Yes!” Within seconds, a furry carcass lands with a thud atop the dike.

“There,” says Jaap de Wit, one of 500 government-hired muskrat trappers. “One less rat to make holes in the dike.”

The latest threat to the Netherlands’ vast system of medieval levees that protect two-thirds of the country from submersion isn’t erosion or even old age: It’s the incessant tunneling of muskrats.

“This is a war we cannot win. But if we didn’t do this, we’d have a disaster in the whole of Holland on our hands,” said Brand Klijnstra, one of 40 official “muskrat fighters” in the central province of Utrecht.

For centuries, the Dutch have paid careful attention to their earthen dikes, some of which date to the Middle Ages. The watch has taken on new urgency since 1995, when widespread flooding of the Maas, Waal and Rhine Rivers forced the evacuation of 250,000 people.

The dikes survived, but inspectors identified dozens of weak points, prompting the government to speed up a $1.4 billion repair and reinforcement plan.

So, it is “zero tolerance” when it comes to the insidious and prolific muskrat, which thrives in the Netherlands’ hundreds of thousands of miles of waterways. There are even muskrat hotlines, part of a $15 million a year effort to thin them out.

“By tunneling beneath the dikes, it’s possible at any minute that a dike could break and unleash floodwaters capable of devastating destruction,” said Ton Tempels, who supervises trapping in the Utrecht region.

“It only takes a few rats in one area to destroy a dike - and we have millions,” he said.

The varmints have been gnawing on the dikes since soon after a Czech count brought six of them from North America to the Netherlands in 1906. He released them and - with no natural predators - they thrived in the abundant wetlands.

One pair can produce up to 50 babies a year, and by midsummer those born in spring are bearing their own young. Within 10 years, naturalists say, there were several million.

In addition to making Swiss cheese of the dikes - a single Dutch muskrat digs out about 13 wheelbarrows of sand each year - the tunnels can collapse beneath the weight of a tractor.

Last year, a Rotterdam farmer drowned in a silty canal when his combine hit a muskrat hole and flipped.

Flooding, though, is the biggest worry.

When muskrats tunneled completely through a dike in South Holland recently, water spurted out and workers frantically patched it before it could give way completely.

The noticeable dips in paved roads atop muskrat-infested dikes have even convinced most animal rights activists of the need for the annual kill-off.


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