Two Moose Creek
Gravel pit pollution dumping directly into King salmon habitat
Two Moose Creek is a tributary to the Anchor River. It runs year-round, and is a stream where King salmon, Silver salmon, Dolly Varden, and Steelhead are known to spawn and rear. Cook Inletkeeper has monitored water quality at Two Moose Creek since 2002 just above the culvert which runs under the Sterling Highway (just after milepost 160, on the north side of the Sterling Hwy).
On April 30, 2012, one of our Citizens’ Environmental Monitoring Program volunteers was taking water quality samples at this site. He came back to the lab with some concerns about the slope above the creek culvert, and the surrounding riparian area. Last fall we had noticed that cutting was done along the banks of the highway, which are quite steep through this small valley. During April more cutting had occurred and logs from that job fell into and over the culvert, restricting the flow of Two Moose Creek into the Anchor River.
At the same time, trouble was brewing upstream. A dam that was built to hold back water from a large gravel pit broke sometime between April 30 and May 14. This breach sent a huge amount of sediment and water downstream all at once. The trees just below the inflow point lost their bark on the upstream side, and all the trees had mud in them over six feet high. Both sides of Two Moose Creek are now covered in two to three feet of sand and mud. The steep banks along the left side of the creek were scoured and continue to slough off into Two Moose, sending more sand and gravel into the creek bed.
Cook Inletkeeper staff and interns began monitoring Two Moose Creek weekly for turbidity. We set up 4 sampling locations: our regular CEMP site just above the culvert, approximately 15 feet up the gravel pit inflow stream, Two Moose Creek approximately 30 feet upstream of the gravel pit inflow, and downstream approximately 50 feet where the inflow waters and the background creek waters were fully mixed.
Turbidity is a measure of water clarity, and gives you an idea of the amount of sand and other fine materials suspended in water. As these sand particles travel, they fall out onto the creek bed, filling in spaces between rocks where fish food – aquatic insects – live. High turbidity has also been linked to stressing spawning salmon, growing juvenile salmon, and the overall reproductive health of salmon.As seen in this chart, the gravel pit inflow (red bars) contributes water significantly more turbid than Two Moose Creek (the blue bars) through the summer and fall of 2012. The state of Alaska’s water quality standard is exceeded when the discharge is more than 5 NTUs (Nephalometric Turbidity Units, the units we use to measure turbidity) above the background. Since sampling began on June 25, the gravel pit discharge has exceeded state water quality standards during the majority of our visits. During the middle and end of September, inflow exceeded background turbidity by over 100 NTUs!
Cook Inletkeeper has attempted to engage the Dept. of Environmental Conservation (Division of Water), the Department of Fish & Game (Div. of Habitat), the Environmental Protection Agency, the Borough and state legislatures on the ongoing degradation of a King salmon stream on the Lower Peninsula. As of December 2013, we have seen no enforcement action and no efforts to remediate the ongoing water quality standard violations. Sedimentation of the creek is continuing, and the riparian zone around this creek is heavily degraded and unstable.