Repair and Safety Improvements
Dakota County has completed numerous large-scale projects over the last 10 years to improve the safety and operations of the Byllesby Dam.
The process started in 2007 with a letter from the Federal Energy Regulatory Commission (FERC) requiring Dakota County to increase the capacity of the Byllesby Dam from 40,000 cubic feet per second (cfs) to 80,800 cfs which is 100 percent of the Probable Maximum Flood, the most severe possible flood calculated by combining information about precipitation, geology and water management strategies.
To meet this requirement, Dakota County upgraded the Byllesby Dam with two new 65-feet wide by 14-feet tall hydraulically operated crest gates to provide flood control. The total project cost $7.5 million dollars, one half of which was provided by the Minnesota Department of Natural Resources Dam Safety Grant Funds.
In 2015-2016, Dakota County also completed repairs to the existing dam structure. Improvements included:
- Large scale bedrock repairs
- Repairing the existing concrete face of the dam
- Adding piers and a bridge over the overflow structure
- Repairing the existing gate systems on the top of the dam
Turbine Upgrade Project
The turbines inside the dam are about 107 years old. They have had several major overhauls and need to be replaced.
Combined with an aging powerhouse structure, it has been determined that an upgrade will be required. Dakota County has finished preliminary designs and determined the process moving forward to replace the turbines and upgrade the powerhouse.
As part of the 2017 legislative session, Dakota County was allocated $6 million dollars in bonding toward the completion of a turbine upgrade project at the Byllesby Dam. The project is working through the design phase and has several hurdles to clear before breaking ground. Dakota County will be utilizing the Best Value Contracting Process to select a turbine manufacturer and a general contractor to complete the project.
Tentative project schedule
Fall-Winter 2017: Selection of turbine manufacturer
Spring 2018: Selection of general contractor
Fall 2018: Start of construction
June 2022: Tentative completion date
Please refer to the Lake Byllesby Dam Projects page for more information on proposals, bidding and potential contracts with Dakota County to complete this project .