Spillway Construction Project

St Cloud Hydroelectric Dam and Mississippi River
The St. Cloud Dam is the largest city-owned hydroelectric facility in Minnesota. It can generate 8.86 megawatts of electricity per day. Although very successful, its current spillway gates have reached the end of their useful life - making the Dam less efficient and safe than it could be. The City of St. Cloud is partnering with the Minnesota DNR to address this problem by installing a new gate system.

A bubbler system installed upstream of the new spillway gates will prevent ice buildup that can cause the gates to fail. This will reduce the need for hydro operators to cut ice from frozen gates - a difficult and dangerous task.
 
Large ice chunks gathering at the St. Cloud Dam during Spring Ice Break-up
Diagram of the Obermeyer Gate System
The Obermeyer Gate System at the St. Cloud Dam on the Mississippi River

The Obermeyer Gate System

 
An Obermeyer spillway gate system has been chosen for the St. Cloud Dam. The system has a row of steel gate panels supported by inflatable air bladders. The elevation of the reservoir is adjusted and maintained by controlling the pressure in the bladders.
 
Obermeyer gates can be set at an infinite number of positions between fully raised and fully lowered. The gates use no high-precision parts of bearings - enhancing the service life and requiring minimal maintenance.
 

 

Benefits Include
  

  • Reduced fluctuations in river levels – increasing opportunities for recreational use and improving conditions for nearby fish populations

  • Increased and consistent energy production

  • Reduced gate icing due to upstream bubbler

  • Improved safety conditions for hydro operators

The St. Cloud Dam