Authorized: Flood Control Act of 1958

Construction: 1965-1977; $130 million as part of the Saylorville Lake Project.

Location/Description:
The Saylorville Lake Project also includes the Big Creek Remedial Works which consists of three dams and a diversion channel, spillway and pump station. The Remedial Works protects Polk City, Iowa.

History: The Big Creek Remedial Works Project was awarded the 1976 Chief of Engineers Distinguished Design Award. Originally Polk City was to be protected with a system of levees, but placing dams both above and below the city eliminated the need for those levees. The Iowa Department of Natural Resources manages the ponding area behind the Barrier Dam as an inviolate refuge during a portion of the year to protect waterfowl.

Big Creek Remedial Works Structures:

• Barrier Dam: The dam protects Polk City from rising water in Saylorville Lake.

• Pump Station: Excess water can be drained into Saylorville Lake via gravity flow through a conduit in the Barrier Dam or pumped when Saylorville Lake levels rise. The primary station has three pumps with 350 h.p. motors which are each capable of pumping 17,000 gpm when Saylorville Lake level is high with 50’ of water head pressure above the pumps. The supplemental pump station has three pumps with 500 h.p. motors which each are capable of pumping 29,940 gpm at 50' of head water.

• Diversion Dam: The dam formed the 880 acre Big Creek Lake and protects Polk City from floodwaters within Big Creek Watershed. A minimum 3 cfs water quality release is maintained from the Diversion Dam through Polk City into the Ponding Area.

• Diversion Channel & Terminal Dam/Spillway: Diverts floodwater from Big Creek Lake into Saylorville Lake. The spillway with a crest elevation of 920.0 NGVD keeps the lake level relatively stable at that elevation.