Improving Our Community Waterways Together

Wet Weather Team Document Repository

In summer 2006, MSD chartered a Wet Weather Team to assist with the development of an integrated Wet Weather Program (now known as the Integrated Overflow Abatement Plan or IOAP) to address the community’s problems with combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs) that may occur under wet weather conditions. Project WIN (Waterway Improvements Now) is MSD’s initiative to implement the IOAP.

The Wet Weather Team consisted of community representatives, elected officials, and MSD personnel. This group of stakeholders assisted MSD in making decisions in the design of the IOAP, so that these decisions could be made wisely and in ways that best meet the needs of the local community. The Wet Weather Team met 22 times from July 2006 through December 2008 during the IOAP development process.

The Wet Weather Team completed its charge in December 2008, when it submitted the Vision for the Integrated Overflow Abatement Plan and a Stakeholder Support Memo to the MSD Board. Both the Vision and the Stakeholder Support Memo received full consensus support from the Wet Weather Team stakeholder group.

MSD is committed to keeping stakeholder participants in the Wet Weather Team informed and engaged during the implementation of the IOAP. Starting in May 2009, MSD has invited former stakeholder members of the Wet Weather Team to participate in periodic IOAP implementation meetings. These meetings are expected to occur semiannually.

The technical team’s analysis of the IOAP according to the WWT’s programmatic values yielded the following conclusions. 

For a list of meeting summaries and materials from Wet Weather Team meetings and IOAP implementation meetings conducted to date Click Here.

Customer Service

The IOAP ensures service continuity by eliminating several small WQTCs and pump stations and by incorporating redundant equipment and standby generators in the proposed projects.  Odor control guidelines have been consistently applied across all projects.  Most storage basins proposed in the IOAP will be covered to minimize odors.  Other storage basin and pump station improvement projects incorporate odor control equipment.

Economic Vitality

MSD’s current rates are near the national average.  The anticipated annual rate increases of 5 to 6.5 percent are consistent with initial estimates of program costs, and they include allowances for future MSD programs as well as IOAP implementation.  Even with these rate increases, MSD’s rates are anticipated to remain at or near the national average, assuming other communities face similar inflation and regulatory pressures.  These estimates are based on current data; many unknown factors (such as, bond market, construction market conditions, etc.) will also affect future rates.


Education is an integral and essential component of the IOAP.  It supports a number of IOAP objectives, including promoting and sustaining participation in green infrastructure and source control efforts, and building a sense of personal responsibility and support for clean water initiatives.

Environmental Justice and Equity

The site selection process followed uniform criteria across the county, with most solutions placed near overflow points and with no homes or private businesses permanently displaced.  Furthermore, the configuration of facilities was based on a uniform application of written design criteria and odor control criteria.  Other nuisance conditions, such as noise, dust, and traffic disruptions will be minimized during the design and construction phases of projects.

Financial Equity

MSD’s rate structure is based on a cost-of-service model tempered by consideration of customers’ ability to pay.  The rate increases proposed to fund the IOAP and other MSD programs will continue to be based on the cost of service, but MSD will recommend to the MSD Board that the existing low income, senior citizen discount program be expanded.  The IOAP also proposes subsidies and incentives for green infrastructure and inflow and infiltration (I/I) control based on their business value for overflow abatement.

Financial Stewardship

As described above, the IOAP is based upon a rigorous benefit-cost analysis that considered a broad range of technology alternatives and different levels of control that met or exceeded regulatory guidelines.  The “knee of the curve” evaluations of IOAP projects demonstrated that the IOAP provides a high level of control, but does not exceed the point of diminishing returns.

Materials for additional meetings will be posted following each meeting.

To view documents for the Wet Weather Team, click here to view the Wet Weather Team folder in the Library. 

Return to Integrated Overflow Abatement Plan (IOAP) Page