SW005 Combined Sewer Overflow Improvements

Project Details:

Project Start Date: 1/1/22

Ongoing Program: Y

Submitting Department: Public Works

Contact Person: Kelly Moriarity

Level of Need: Significant

Estimated Project Completion Date: 12/31/27

Department Priority: 5 of 6

Contact Phone Number: 612-673-3617

Website: TBD

Project Location:

Address: citywide

City Sector: Citywide

Affected Neighborhoods: Citywide

Affected Wards: All

Description of Location

Project Description:

The purpose of this program is to remove the direct inflow of stormwater to the sanitary sewer system and redirect it to the storm drain system where appropriate. This program was developed to remove inflow from public sources and provide facilities for private disconnections where no storm drain currently exists in the area. This program is also used to complement an inflow and infiltration (I&I) reduction program consistent with the Metropolitan Council Environmental Services (MCES) Ongoing I&I Surcharge Program. Inflow is typically flow from a single point where stormwater is entering the sewer system directly through stormwater inlets or discharge from sump pumps, downspouts, and foundation drains. Infiltration usually means the seepage of groundwater into sanitary sewer pipes through cracks and joints. Specific activities typically consist of adding new storm drains.

Purpose and Justification:

The purpose of the program is to implement projects that will reduce the amount of clear water in the sanitary system and reduce the risk of overflows of untreated sewage mixed with stormwater to the Mississippi River during severe rainstorms. The program is necessary because the City’s storm and sanitary sewer systems were originally built as combined systems.

The City is required under the National Pollutant Discharge Elimination System (NPDES) program to eliminate point source discharges to surface waters. And, the reduction of clear water in the sanitary sewer system is required by MCES, which provides regional wastewater collection and treatment. The MCES ongoing I&I Surcharge Program is based on peak flows from the city sanitary system which occurs during large rain events. The program requires communities to continually invest in the system and make progress in removing I&I.

Project Visuals and Map:

Project Cost Breakdown

Department Funding Request


Have Grants for this Project been secured?

None at this time

Describe status and timing details of secured or applied for grants or other non-City funding sources:


Describe any collaborative arrangements with outside project partners, including who they are and what their role is with the project:

Several projects require collaboration with various watershed districts or organizations. We also look to coordinate these projects with other planned work including street reconstruction both by City and external agencies.


State Law Chapter 462.356 (Subd. 2) requires review of all capital improvements for compliance with the comprehensive municipal plan. Chapter 13, Section 4 of the City Charter requires Location and Design Review for the purpose of approving the sale of bonds for these projects. Describe how the project is consistent with the adopted City/Park Board comprehensive plans and how the project implements goals and policies as stated in the adopted plans, including specific policy references:

Goal 11 - Clean environment: In 2040, Minneapolis will have healthy air, clean water, and a vibrant ecosystem. (Policy 72:Sustainable Water System Management, Policy 73:Stormwater Management, Policy 74:Integration of Water Management into Development)

Goal 10 - Climate change resilience: In 2040, Minneapolis will be resilient to the effects of climate change and diminishing natural resources, and will be on track to achieve an 80% reduction in greenhouse gas emissions by 2050. (Policy 72:Sustainable Water System Management, Policy 73:Stormwater Management, Policy 74:Integration of Water Management into Development)

This project is consistent with planning and policy guidelines set forth in the City’s comprehensive plan Minneapolis 2040

Provide the date that Location and Design Review was conducted for the project, the outcome of that analysis and the date formal action was taken by the Planning Commission:

Location and Design Review for this project took place on May 4, 2009. The project was found consistent with the City’s comprehensive plan. No additional review is required

Economic Development

Will the project contribute to growth in the city’s tax base? No

Describe the economic development impact of the project:

Recovering capacity in the sanitary sewer system thru separation of stormwater can allow for new/increased sanitary flow from development.

Does the project support redevelopment opportunity that without the project would be infeasible?



Is the proposed project on an existing or planned transitway, transit route, or high-volume pedestrian corridor? If yes, provide details on how the project will improve the transit and/or pedestrian experience.


Does the proposed project anticipate multi-modal enhancements (sidewalks, bicycle or transit facilities)? Provide details.


Is the right-of-way constrained and do you anticipate that modes of travel will be competing for space? Provide details, is there potential for innovative design options? Provide details


Operating Impacts

Operations & Capital Asset Maintenance:

Is this request for new or existing infrastructure? New

What is the expected useful life of the project/Improvement? 100 years

Year that Operating Incr/(Decr) will take effect?

What is the estimated annual operating cost increase or (decrease) for this project? N/A

Any Prior Year Remaining Bond Authorizations? No

Prior Year Remaining Bond Authorizations:

Describe how operating cost increases or decreases were determined and include details such as personnel costs, materials, contracts, energy savings, etc:

There is a very small increase in the overall 566 mile storm drain system as a result of this program for the remaining CSO locations. Clear water is also removed from the sanitary sewer system as a result thus reducing the City's sewage treatment costs.

If new infrastructure, discuss how the department/agency will pay for the increased annual operating costs:

Any increase would be paid from the Stormwater Utility enterprise fund.

For new infrastructure, describe the estimated timing and dollar amount of future capital investment required to realize the full expected useful life of the project:


Project Coordination

Describe completion status for ongoing projects and how and when the department/agency plans to use the prior year remaining bond authorizations:


If this is a new project, describe the major project phases and timing anticipated for completing the project:


Scalability/Funding Allocation Flexibility – discuss any flexibility to increase or decrease funding among the years in the five-year plan and the most that could be spent in a given year:

This program funding has decreased from past levels to reflect the overall status of the CSO program and the transition from a CSO permit environment to an Integrated MS4 permit. There is also some flexibility among years, although it is most effective to have the consistent program amount available each year.

Minneapolis Goals and Strategic Direction

Minneapolis is a growing and vibrant world-class city with a flourishing economy and a pristine environment, where all people are safe, healthy and have equitable opportunities for success and happiness.

Stormwater system analysis, design and operation activities are driven by data and computer models. Using data to define these activities reduces the potential for bias and results in a more equitable service level across the city. Providing storm sewer capacity where needed to keep rain water out of the sanitary sewer system minimizes the risk of sanitary backups and combined sewer overflows to the Mississippi River. New facilities are planned to address expected outcomes from climate change. Below is a description of how this project meets City Goals.

Public Services

The City prioritizes reliable and equitable access to high-quality public services.

Work collaboratively between City departments to ensure utility budgets are adequately funded to maintain aging infrastructure systems

Prioritize and reserve the City’s sanitary and storm sewer capacity for its intended purpose and prohibit groundwater or other waste streams from entering the storm or sanitary sewer infrastructure unless the City gives approval.

Environmental Justice:

The City prioritizes sustainable practices and renewable resources to equitably address climate change while restoring and protecting our soil, water and air.

Manage the city’s surface waters, groundwater, stormwater, wastewater and drinking water equitably and sustainably, while minimizing the adverse impacts of climate change.

Use hydraulic and water quality models and data about infrastructure condition and risks to prioritize and inform investments in sanitary and storm infrastructure.

Continue work to reduce risk of overflows from the historically connected sewers and work to reduce infiltration and inflow into the city’s sanitary sewer system through infrastructure improvements.

Consider climate forecasts in stormwater feasibility and modeling work to inform infrastructure investments.

Explore the impacts of flooding on public safety, the protection of property, public infrastructure and the environment.

Improve the tree canopy and urban forest.

Built Environment & Transportation:

The City prioritizes high quality neighborhoods, streets, infrastructure and equitable access to multimodal transportation in all parts of the City through thoughtful planning and design.

Manage and design transportation infrastructure with a priority on water quality through the reduction of stormwater runoff and pollutants including road salt.

Maximize the use of public property to meet flood mitigation and water quality goals via green infrastructure and other stormwater best management practices

Use infiltration best practices and bio-infiltration to reduce stormwater impacts on surface waters.

Encourage and require reductions in amounts of impervious surfaces. Pilot and promote permeable surface solutions as alternatives to impervious surfaces.

Additional Information

Add any additional information you feel is important for the CLIC committee, Mayor, City Council members or the general public to know about this potential project and why it should be approved: