Stormwater Utility

The stormwater utility fee is similar to a water or sewer fee. In essence, customers pay a fee to convey stormwater from their properties. The utility is the result of unfunded United States Environmental Protection Agency (EPA) and the Michigan Department of Environmental Quality (MDEQ) mandates that force cities like St. Clair Shores to manage stormwater within their jurisdiction. The fee is used to finance annual compliance with the National Pollutant Discharge Elimination System (NPDES) permitting standards. The NPDES is the compliance system for the Clean Water Act (CWA) and requires that all stormwater discharges that enter waters of the United States must meet minimum federal water quality requirements.

Stormwater begins as rain or snowmelt that flows over land rather than seeping into the ground. It flows over hard surfaces (impervious surfaces) such as roofs, driveways, walkways, and pervious surfaces such as grass, gardens, and woodlands into the city’s combined sewer system. The more hard surface (impervious surface) on your property, the more stormwater runoff is contributed to the sewer system.

This drainage either flows into the same underground pipes as sewage and must be treated at the Great Lakes Water Authority (GLWA) wastewater treatment plant before it can be released back into the environment or Lake St. Clair through a separate stormwater sewage system.

The SESMD bills the City of St. Clair Shores for the conveyance and treatment of combined sewage at GLWA.

While stormwater is a result of rain and snowmelt, the stormwater fee is not related to how much rain falls on your property, but rather the facilities used to manage stormwater such as sewers, manholes, catch basins and wastewater treatment. The more hard surface a property has, the more it uses the stormwater system components.

Since 1993, the city has had a stormwater utility ordinance that requires property owners to pay a user fee related to the operation and maintenance of the city’s stormwater system. The current stormwater utility ordinance was developed based on a 1992 Stormwater Utility Implementation Report prepared by McNamee, Porter & Seeley, Inc. This 1992 report is now 30 years old and has not been updated based on recent court rulings. The Michigan Supreme Court has since ruled on stormwater service charges, in particular as related to violating the “Bolt Criteria.”  The Michigan Supreme Court ruled that the stormwater service charge imposed by Lansing was unconstitutional and void on the basis that it was a tax for which voter approval was required and not a valid use fee. The Court established three criteria for distinguishing between a fee and a tax:

1. a user fee must serve a regulatory purpose rather than a revenue-raising purpose
2. a user fee must be proportionate to the necessary costs of the service; and
3. a user fee must be voluntary--property owners must be able to refuse or limit their use of the commodity or service

The outcome of this study recommends the City adopt an updated methodology as a basis of billing for stormwater charges that meets the three aspects of the “Bolt Criteria.” This study has determined a methodology to assign all properties within the City their proportional share of the service cost to capture, convey, and treat the stormwater that runs off each property and to meet the needs of the City’s stormwater regulatory obligations. The study recommends using the direct impervious vs. pervious surface area and total property area to determine the property’s direct runoff potential. This entails an individual review of each residential lot by size/zoning classification and every non-residential property to calculate square feet of imperviousness for each parcel. Once PRP is determined, there are no zoning classifications or groups of properties. All calculations are based solely on impervious vs. pervious area and the particular benefit each property receives due to the stormwater system. Other general items that were looked at that affect stormwater were topography, soils, property maintenance, and access to stormwater facilities.

This fee considers all aspects of managing and maintaining a separate stormwater management system. The previous charges did not adequately capture the total operation, maintenance, and capital improvements cost. The new fee provides the necessary revenues to make sure the city meets its responsibilities under Federal and State requirements.  This is done by ensuring proper maintenance and operation of the city’s forty-plus pumping stations, conveying water off properties and roads into the drainage system, and providing for continued stormwater system upgrades. The expenditures for the stormwater management system are approved each year by the Mayor and City Council as part of the city’s fiscal budgeting program.

The fee is based upon the property runoff potential, or PRP, of each parcel in the City of St. Clair Shores.  PRP is based upon hydrologic engineering principles for calculating runoff that uses both the impervious surface area and the pervious surface area.  All surfaces will generate some amount of runoff during precipitation events and can be assigned a runoff coefficient to represent the fraction of the precipitation that results in runoff.

Runoff potential is based on the following formula:  

• Property Runoff Potential(sft) = .20 x [Total Area-Impervious Area] + 0.9 x [Impervious Area]

This factor is then multiplied by the per square ft rate that is determined by the fiscal budget

Areas identified as impervious: 

• Hardened surfaces on or near the ground: sidewalks, private roads, private streets, parking lots, walkways, patios, concrete slabs, runways, taxiways, aprons, or other hardened surfaces consisting of asphalt, concrete, or other paving material
• Hardened surfaces above ground: buildings, foundations, storage tanks, rooftops, athletic courts, and tracks 
• Gravel and dirt driveways and pavers that do not meet requirements to be classified as pervious
• Paved decks adjacent to pools 
• Wooden decks covered by a roof or having an impervious underlying surface
• Surface water that is not part of the public conveyance system

Areas identified as pervious: 

• grass 
• gardens 
• landscaped areas without impervious underlying membrane 
• natural rock formations 
• dirt paths 
• pavers set in porous fill (photos, design plans, and specifications must be submitted) 
• porous pavements (photos, design plans, and specifications must be submitted)

The Southeast Michigan Council of Governments (SEMCOG) conducted an aerial survey of the region in 2015 that was analyzed to determine the building footprints and impervious surface areas. The resulting data sets were provided to each community, and the building footprint and impervious surface area data sets were used for this study and supplemented with other commercially available data sets. The impervious surface area measurements made using the SEMCOG data were verified for properties of different types by visually analyzing aerial photographs of the individual parcels. This factor also corresponds to the factor used in the 2017 Stormwater Asset Management Plan.

Yes, Roads and public rights-of-way maintained by the city are not exempt from the stormwater utility fee. City-owned properties such as parks and parking lots are also subject to the stormwater utility fee. Fees owed by the city as part of this stormwater utility are budgeted in the city’s General Fund or Streets Fund.

The revenues from the Stormwater Utility can only be spent on stormwater-related activities. They will provide a steady funding source for much-needed operations and maintenance activities, maintenance of stormwater structures, replacement and installation of pump stations, and the city’s federally and state-mandated stormwater quality management program.

Fairly accurate, but the impervious area analysis images are not without error. A review and appeal process exists within the city’s Code to address those errors and ensure every landowner is paying their fair share.  

You can implement a few features on your property to gain credit.

Rain barrels harvest and store water from your rooftop by collecting it from a gutter downspout. The stored runoff can be used for watering or other purposes that don't require drinking water. Rain barrels offer several advantages. Using the runoff for watering can reduce your water bill, benefit your plants, and help rain percolate into the ground and recharge groundwater supplies.  A credit equal to 100 sft of impervious area per rain barrel is in use.

Rain gardens are planted depressions of deep-rooted native vegetation designed to absorb excess rainwater runoff from a house or other impervious area with the purpose (besides being beautiful) of allowing rainwater to pool in a low spot just long enough to percolate into the ground. Cisterns are water management devices that provide retention storage volume in above or underground storage tanks. 

Cisterns are often larger than rain barrels, with some underground cisterns having a capacity of 10,000 gallons. Only one credit can be taken for utilizing a dry well or cistern.

Drywells are small, excavated pits backfilled with aggregate and used to infiltrate “good quality” stormwater runoff, such as uncontaminated roof runoff. Drywells are not to be used for infiltrating any runoff that could be significantly contaminated with sediment and other pollutants, such as runoff from high-potential pollutant loading areas and parking lot runoff. Only one credit can be taken for utilizing a dry well or cistern.  Credit for these depends on the design capacity for each.  

The amount will be credited on the following quarter’s water/sewer bill.