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Gray's Bay Dam Closed for 2019 Season

Monday, December 23, 2019

The Gray's Bay Dam has officially been closed and winterized for 2019, after Lake Minnetonka reached a level considered optimal for handling spring snowmelt. 

The Gray’s Bay Dam is located at the outlet of Lake Minnetonka into Minnehaha Creek. The dam was built in 1979 to help control flooding on Minnehaha Creek and Lake Minnetonka. MCWD operates the dam according to a detailed operating plan developed over the course of 10 years with local, state, and federal partners.

An important piece of this operation is creating storage space in Lake Minnetonka to store the the spring snowmelt. The operating plan calls for lowering Lake Minnetonka until it reaches an elevation below 928.60 feet above sea level (Zone 6 in the operation plan below). MCWD closed and winterized the dam on December 23, 2019, when Lake Minnetonka fell below that level.  

Winterizing the Dam
The dam uses three control gates to prevent the flow of water out of Lake Minnetonka. Over winter, we raise these gates to prevent damage from ice and replace them with aluminum beams known as "stop logs." These stop logs prevent any water from passing during the winter months. 

Preventing this flow during the winter months is important for preventing ice jams from forming on Minnehaha Creek. Prior to the dam, ice jams caused flooding along the creek, including a significant flood in 1966 that was the impetus for installing the current adjustable structure. 

The stop logs will be removed in the spring as ice conditions allow.   

2019 Stats & Facts

Water Levels Resources