Minneapolis Public Works 101: Stormwater Tunnels

Deep beneath our downtown streets, as well as in parts of Southeast Minneapolis, Public Works maintains several miles of large underground stormwater tunnels. These tunnels are 100 feet below the surface. They were carved out of the sandstone that lies beneath the bedrock limestone in the 1930s to funnel stormwater to the Mississippi River.

When the tunnels were installed 80-some years ago, the builders didn't backfill around them. That situation was exacerbated over the decades by groundwater pressure, allowing void spaces to open up around the outsides of the tunnels and causing some shifting and cracking in the tunnels themselves. The 20-person crew that inspects and maintains these tunnels has been working on filling the void spaces for several years. Because the storm tunnels can quickly fill with water during even a minor rain event, the crews can only undertake this type of major rehabilitation work during the winter months.

The work itself isn't for everyone. New employees are taken down to the tunnels for a mile walk underground before they're hired to ensure that they won't have issues with this specialized workplace. The crews need to be prepared to work in boots, raincoats and gloves in tunnels with water that is sometimes ankle-deep or higher.

Supplies are lowered through access points and then moved by wheelbarrow through tunnels that are often less than 6 feet high. In addition to the water, workers also encounter the occasional bewildered raccoon or albino fish in the tunnels close to the river.

Just like the streets one hundred feet above, the tunnels even have street signs (like the one for 1st Ave N at left) to let workers know where they are.

This stormwater tunnel work is just one example of the many jobs undertaken by the City of Minneapolis Public Works Department.

(Photos courtesy of Shannon McDonough)

Pay Attention to Your Water Lines in Winter

When our winters get really cold, freezing temperatures force the frost line deeper underground where it can reach the water service line to your home. This can freeze water in the pipes and prevent it from getting to your faucets.

While water mains are maintained by the City, lines that bring the water from the mains into homes and buildings are the responsibility of property owners. If your service line is frozen, you’ll need to contact a qualified contractor who specializes in thawing frozen service lines. Call 311 for information on contractors who do this type of work.

For more information, including tips on preventing water lines from freezing, go to the City’s website.

Minneapolis Water Works Wins Award

Minneapolis Water Treatment and Distribution Services is among just nine public drinking water systems in the nation to receive the Sustainable Water Utility Management Award from the Association of Metropolitan Water Agencies. This is the first year the association has presented the award, which recognizes water utilities that have made a commitment to management that achieves a balance of innovative and successful efforts in economic, social and environmental endeavors.

Minneapolis was recognized for incorporating strategies and financial procedures such as requiring the water division to maintain a minimum cash balance equal to approximately three months of operating expenses to keep cash flow available and implementing a five-year capital improvement program that details each construction project, its estimated cost and where the source of funding. The association also noted the addition of a fixed rate in utility billing that helps stabilize revenues from fluctuations in water use due to weather and the declining water demand by customers. Minneapolis was also recognized for encouraging its customers to use water wisely and being engaged in other environmental stewardship initiatives, including sustainable design in capital projects, efficient vehicles, collaboration on source water protection, supporting urban farms and community gardens, promoting the value of drinking water and reducing the use of disposable water bottles.

This is not the first time Minneapolis has received an award from the Association of Metropolitan Water Agencies. The City received the organization’s Platinum Award for Utility Excellence in 2011 and the Gold Award for Exceptional Utility Performance in 2002.

City’s Director of Water Treatment & Distribution Services Retires

Bernie Bullert The very recently retired Bernie Bullert served for several years as Director of Water Treatment and Distribution Services for the City of Minneapolis.  At first glance, his position may not seem to have much to do with the daily lives of Minneapolis residents. However, changes and improvements Mr. Bullert made to the state’s largest water utility have had an impact on every Minneapolis water user. When he first took on his position, Minneapolis water rates were rising at an unsustainable rate. Under his supervision and focus on operational efficiencies, the projected annual rate of increases was reduced by 40%. At the same time, he was instrumental in developing plans for a back-up water supply, eliminating longstanding taste and odor issues, and addressing deferred maintenance. The contributions he has made to the Water Division will last long after his departure, so remember him the next time you enjoy a glass of Minneapolis water.