Friday, March 22, 2013

TNC lobbies for Silver Creek projects

Advocates say dredging, wetlands are good for system

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By KATHERINE WUTZ
Express Staff Writer

Silver Creek, south of the city of Bellevue, is a fly-fishing mecca for many locals and visitors. Advocates of two projects aimed at restoring Kilpatrick Pond say the projects will lower water temperatures and relieve stress on rainbow trout, but opponents worry that the projects will raise stream velocity and make the area harder to access for anglers. Courtesy photo by Brian Tuohy

    Conservationists, engineers and a Picabo landowner argued during a public hearing Tuesday that a 1,100-foot stream restoration project in Silver Creek would make the watershed healthier without harming fishing or access.
    Dayna Gross, Silver Creek watershed manager for The Nature Conservancy, said her organization and Picabo Livestock Co. President Nick Purdy have been contemplating such a plan for more than 20 years.
    “It’s taken a long, long time to get to this point,” she said.
    Gross said that at its heart, both the portion of the project upstream from Kilpatrick Pond owned by The Nature Conservancy and the portion downstream owned by Nick Purdy are about making the Silver Creek watershed healthier and a better ecosystem for the rainbow trout and mayflies that make the area their home.
    Gross said Kilpatrick Pond is essentially a heat sink, held in place by a 100-year-old dam that causes sediment deposits in the pond. During the summer, the pond heats up, increasing the water temperature not only in the pond but in the entire creek downstream.
    “The surface area [of the pond] is so large that the water warms up and goes over the dam and just stays hot in the system,” she said. “This pond is just a big blockage in the system. Until you address this dam, Silver Creek is not going to be a fully functional spring creek system.”
    The new dam will include a fish passage where fish can go upstream and down through a series of foot-high drops. It will also have a series of “underflow” pipes, which will help the cool water at the bottom of the pond flow into the stream.
    Gross said the pond’s health is marred by sediment, which raises the bed of the pond as well as the temperature, promoting the growth of algae and reducing the amount of healthy vegetation and flies that survive. Below the pond, she said, there are significantly more brown trout than rainbow trout, because brown trout can better adapt to the higher water temperatures.
    Gross said much of The Nature Conservancy’s plans are to dredge the channel, using sediment to fill in areas where the water is shallow and unfishable, creating wetland habitat.
    Chuck Brockway Jr., a partner in engineering firm Brockway Engineers, said Purdy plans to dredge the pond and part of the stream as well, using the sediment to raise the center of the pond and create a wetlands island.  
    Brockway said the island will create two relatively wide channels on each side, and the total area where water can flow will remain the same; instead of being at the bottom of the pond, the sediment will just be in the middle.
    As a result, he said, the average velocity of the stream will remain the same, enabling anglers to still use floating tubes and wade out to fish—a major concern for most anglers. Gross said the same is true of The Nature Conservancy’s portion, though the stream will not look terribly fishable or healthy during construction.
    “It looks really bad when you’re working on it, but it sure comes around pretty quickly,” she said.
    John Huber, a fly-fishing guide and operator of Picabo Angler, said during public comment that he has heard anglers express concern that public access will be cut off.
    “There’s been a lot of fear-mongering about what this project will do about our access,” he said. “The nature of the access may change but the access won’t.”
    Other anglers, however, said they still had concerns about water temperature and velocity. The hearing brought a standing-room-only crowd and garnered what County Commissioner Larry Schoen called “among the highest” volume of written public comment he had seen as a commissioner.
    No decisions were made Tuesday, but the commissioners said they would continue discussions next month.
Kate Wutz: kwutz@mtexpress.com