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Macroinvertebrate Assessment on Kilpatrick Pond


Conducted in cooperation with
Partner's logo
Partner's logo

Silver Creek's natural channel widens and slows at a stretch known as Kilpatrick Pond. Sediment has built up behind an irrigation dam built in the late 19th century, slowing water velocities and increasing water temperatures to levels that stress trout and other cold-water adapted organisms. The Nature Conservancy has documented that during summer months, water temperature in Silver Creek increases by as much as 10°F as it flows through Kilpatrick Pond. This amount of increase can severely stress fish and other cold-water adapted organisms

Hester Dendy sampling device.
Hester Dendy™ sampler provides
artificial substrate for insects to
colonize. Photo USGS
Kilpatrick Pond flows through land owned by The Nature Conservancy (upstream of the Kilpatrick Road bridge) and the Picabo Livestock Company (downstream of the bridge). The two entities have proposed joint projects to remove sediment, form wetland habitat, restore a channel to increase stream velocity, and replace the irrigation dam to allow fish passage.

The primary goal of the projects is to restore Silver Creek’s cold-water ecosystem within and downstream of the project area.

How the USGS Helps

Beginning in June 2013, we installed sampling devices at seven sites: five sites within the pond and one each upstream and downstream of the pond. The sampling devices provide artificial substrate that aquatic insects such as mayflies, caddisflies, and stoneflies can colonize. We're also measuring water velocity, depth, temperature, and dissolved oxygen.

Three macroinvertebrate sampling devices.
Three macroinvertebrate sampling
devices. Photo USGS
Sampling will continue seasonally—spring, summer, and fall—for two years after the restoration project is completed. Initial samples collected before restoration begins will provide baseline data. Comparisons with data gathered during and after the restoration project will assess how well and how quickly aquatic insects recolonize Kilpatrick Pond.


We will publish a report in 2017 to summarize results after monitoring is completed.