Buy Credits

Developers can save money with StormStore. StormStore is a tool to help you get the most out of recent legislation changes enabling stormwater credit trading in Cook County, Illinois. Eligible projects could have saved on average $175,000 each with StormStore from 2006-2019.

The StormStore team can help you get the most out of the newly established stormwater credit trading market in Cook County, Illinois. Trading is a cost-effective way for developers to meet stormwater requirements while ensuring all communities benefit from local flooding solutions built where they are needed most.

Reach out to the StormStore team today! We help clarify the murky waters of stormwater credit trading by providing pro bono assistance for municipalities, private developers, community groups, and landowners in Cook County. Let us help you take advantage of the cost-savings benefits of participating in stormwater credit trading.

Is your project eligible?

How would StormStore work for your project?

If your project is eligible, you now can use credits to meet a portion of your stormwater management obligations. Developers stand to save on average $175,000 in avoided stormwater management costs and can free up to 30,000 sf of land for other use. Follow the steps below to see where StormStore can help you navigate this innovative program and help save you money.


To take advantage of this pilot, developers will need to do the following:

  1. Identify need - Work with your project engineer or planner to determine how many credits you can use.
  2. Secure Credits - Find credits from an offsite facility in the same watershed. You can check with your municipality to determine if there are available credits for sale or visit MWRD's pilot website to see a list of approved credit supply projects.  Reach out to the credit supplier for the cost of available credits,
  3. Obtain Permit Approval - Submit a watershed management permit to MWRD that documents your agreement with the credit supplier and the number of credits you will use to meet your stormwater management obligations.  Agreements will come in the form of a binding contract between you, the Buyer, and the credit Seller and can be used as proof of purchase.
  4. Construct Project - Once you have received your permit, you are free to construct your project. You are responsible for the maintenance of the infrastructure on your site. The Seller from who you purchased credits is responsible for maintenance of their site in perpetuity.

Frequently Asked Questions

Simply put, it's a unit of stormwater storage. Each stormwater credit represents 1 acre-ft of stormwater retention or detention storage. You can buy and sell more or less than 1 acre-ft per trade depending on your project needs. Currently MWRD’s WMO caps the number of credits that can be purchased or traded by developers in order to minimize the rise of damage to local community and regional water resources and adjacent properties. Today developers can meet their stormwater management requirements by trading or purchasing up to 50% of their volume control or retention storage needs and the difference between the 10-year and 100-year detention volume needs. Reach out to the StormStore team to help you figure out how many credits you are eligible to buy or check out MWRD's WMO for more details on how to calculate your project’s stormwater management requirements.
In the Little Calumet or Lower Des Plaines Watershed Planning Areas any developer who triggers the MWRD’s watershed management ordinance (WMO) is eligible to purchase credits to meet their compliance obligations. Per the WMO, most developments over 0.5 acres are required to provide stormwater management onsite, but starting in May 2020 MWRD is allowing developers to meet a portion of their stormwater management requirement using off-site facilities. StormStore can help developers find and match with available offsite facilities so that you can more cost-effectively meet your management obligations.
During this pilot phase there is no cost to participate in StormStore so it's a great time to consider StormStore to meet your stormwater compliance needs! The StormStore team is currently providing administrative services pro bono to early participants who are looking at buying or selling credits. Let us help you assess your site, find your match and negotiate a trade...
The cost of each credit will need to be negotiated on a trade by trade basis between the buyer and seller. Typically the seller will set the sale price based on the total pre-planning, planning, design, construction and long-term maintenance costs for the facility they build. Even with all these costs included the credit price will often result in cheaper, easier, and greener stormwater management projects for buyers. Currently there is no maximum or minimum credit price - however we have seen early estimates of credit prices that range from $150,000 to $300,000 per credit (or per acre-ft of storage). This number will vary and generally depends on the type of credit being offered (detention vs volume control) and the type of stormwater facility used to generate the credit (grey vs green). The StormStore team can help credit generators figure out the right price point for them and walk you through how to negotiate with potential buyers.
There are no conditions that limit who can build, buy or sell projects as long as eligibility criteria are met or restrictions on where projects can be built and traded in the pilot Lower Des Plaines and Little Calumet watershed planning areas. The only requirement is that credits can only be traded within the same watershed. This means that if you build a rain garden in the footprint in the Little Calumet Watershed Planning Area you can only sell or trade credits to potential buyers who are developing projects in the Little Calumet watershed area.
MWRD does not currently certify credits but does track trades through their existing stormwater permit process. To ensure compliance with MWRD’s WMO and secure a trade, buyers must submit a stormwater permit for approval and identify the offsite facility that will be used to meet stormwater management obligation using the offsite facility’s MWRD issued permit number. The buyer will also need to share the purchase or trade agreement made with the offsite facility owner with MWRD prior to project construction.
Developers in the scoping and planning stages of a new development or redevelopment project that is likely to trigger MWRD’s WMO should also consider looking to see the cost-benefit of offsite compliance. Projects that have shown significant cost savings are those that may have site limitations like poorly infiltrated soils, suspected contamination, significant number of underground utilities, or require the use of underground detention facilities.


Let's Talk StormStore (Infographic)

StormStore: So buyers and sellers of stormwater credits can easily make a deal! Learn more »

Training Webinar (Video)

Designed for civil engineers, this webinar showcases the pilot program and answer questions about what projects are a good fit. It will also describes the pro-bono support available through the StormStore partnership. Learn more »

Municipal Guide (PDF)

Brief handout for municipal staff who are interested in StormStore. Learn more »


Contact the StormStore team today!

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