Project Reports

Supplemental Environmental Assessment & Finding of No Significant Impact - Sandy Point Bend Chute Complex Adaptive Management

Published July 23, 2015
Expiration date: 8/21/2015

Title: Supplemental Environmental Assessment & Finding of No Significant Impact - Sandy Point Bend Chute Complex Adaptive Management, Harrison County, Iowa
 
Summary: The original project, consisting of two chutes with four intermediate tie channels connected to the main channel of the Missouri River, was constructed in 2012 to function as shallow water habitat intended to benefit the federally endangered pallid sturgeon and other native fish and wildlife species. Over time, the constructed chutes have become deeper and wider than designed, resulting in them currently pulling more water out of the Missouri River main channel than the original design specified.

Measures would include (1) constructing three stone sills across the three Missouri River tie channels to prevent the tie channels from flowing during low flows, (2) modifying existing control structures at the two main channel inlets to allow all life stages of fish (particularly larvae and young-of-year fish) the ability to access the complex, and (3) modifying control structures downstream of the inlets to control the amount of flow entering the chutes. These adaptive management activities would rectify any adverse impacts to Missouri River navigation channel depths and improve habitat quality within the chutes by decreasing depths and velocities.
 
Geographic Scope: Along the right descending bank of the Missouri River between river miles 657 and 658 in Harrison County, Iowa.
 
Impacts: None
 
Decision/Date: Made following close of public comment period.