In 1999, Puget Sound Chinook salmon and Hood Canal summer chum—two salmonids found in the Dungeness River—were listed as threatened species. In 2000, Dungeness Bay was closed to shellfish harvesting due to high fecal coliform bacteria counts. The network of irrigation ditches in the valley contributed to habitat problems in the river and pollution problems in the bay.
FINDING A COMMON PATH
As a first step towards addressing pollution problems, Clallam Conservation District worked with irrigation districts and companies to upgrade their open ditch irrigation systems to pipeline systems. This led to larger, more comprehensive ditch piping projects that not only eliminated pollution, but also conserved substantial amounts of water that was leaking from the inefficient ditches.
RESULTS ON THE GROUND
In 2001 and 2002, Clallam Conservation District helped pipe three irrigation ditches that had been identified as contributing to pollution in Dungeness Bay. With the implementation of additional projects, water quality steadily improved, and in 2011, 500 acres of Dungeness Bay were upgraded from “Closed” to “Conditionally Approved” for shellfish harvest. Since 2000, nearly 50 miles of irrigation ditch have been piped in the Dungeness Valley, resulting in water savings in excess of 14 cubic feet per second—that’s over 9 million gallons of water per day. This is a 25 percent reduction in irrigation water withdrawals over the past 13 years. In 2013, salmon returned to the Dungeness River to spawn in numbers not seen in half a century.
The piping of 50 miles of irrigation ditch has required patience and perseverance. Some people didn’t believe it needed to or could be done. It has taken over 40 grants from 15 sources, investments in quality design work, and good project oversight to achieve this success.
“The Clallam Conservation District has taken the major part in the leadership and funding of water conservation and water quality in the Dungeness Valley over the past 15 years,” said Gary Smith, Sequim Prairie Tri Irrigation Association member. “Without the District’s leadership and commitment to water issues, the reduction of irrigation water outtake from the Dungeness would be a small fraction of what has been accomplished to-date.”
To learn more about projects involving private landowners, read Conservation in Washington: Powered by People – a collection of conservation district stories about successful natural resource projects on private lands across the state.