Regulatory flexibility could save $5 million for Decatur taxpayers
The City of Decatur contains many neighborhoods with combined sewers in which sanitary sewage and storm water run through the same pipe. During heavy rains, this can result in basement backups and street flooding as there is a greater volume of water running through the pipe than the pipe’s capacity. There are numerous ways to reduce this problem with two of the most common being: 1) separating the combined sewers into a pipe for sanitary sewage and a pipe for storm water, and 2) separating combined sewers in locations where flooding is most prominent, storing storm water in a retention basin (while sanitary sewage continues to travel to the treatment plant), and then returning the storm water to a downstream combined sewer only after the volume of water in the combined sewer is at a level where flooding and sewer back-ups are no longer a risk. When costs are equivalent, it is financially prudent to separate sanitary sewage and storm water. However, in some cases there are substantial cost differences to alternatives that yield equivalent levels of protection from flooding and basement back-ups. In these circumstances, cities should move forward with a different approach.
At its last meeting, the Decatur City Council voted 4-2 to move forward with a professional engineering services agreement for the Oakland and Grand area sewer separation project that is estimated to cost city taxpayers $15.6 million. While the project has complete separation of sanitary sewer and storm water, it is $4.9 million more expensive than a $10.7 million alternative project that involves temporarily storing storm water in a retention basin (sanitary sewage continues down the pipe) before the water is released back into a downstream combined sewer when volumes of water pose no risk of flooding. Both options will reduce 25-year flood risk and basement back-ups at equivalent levels, one option is 45% more expensive.
In addition to saving taxpayers $4.9 million, there are other advantages to using a retention basin to store storm water. Numerous municipalities have found ways to use retention basins as recreational areas during times when there is no water in the basin (e.g., creation of a skate park). Creation of a recreational area in our urban core can further our neighborhood revitalization objectives, while costing less money.
The city of Decatur could also use the savings to pay for other projects needed to reduce flooding. On August 2 and 3, heavy rains in Decatur damaged at least 5 vehicles parked on W. Prairie Ave. This resulted in $10,000’s of property damage to the vehicles including at least one total loss. I thank the Decatur Public Works Department for their prompt installation of warning signs in flood prone areas as a way to warn people. With that said, a longer-term solution is for the city to spend some of the $4.9 million in potential savings from the Oakland and Grand sewer separation project to ensure that employees and customers of downtown businesses do not have their cars flood while parked downtown.
Decatur’s population has declined every year this century, our labor force continues to remain near decades lows, and we are one of the poorest cities in Illinois. We should not pay $4.9 million more for this project, particularly given that the city has not even formally asked the regulatory agencies including the USEPA and IEPA about possible alternatives. Hopefully, when the city does ask, the USEPA and IEPA will support creative efforts to reduce flooding and sewer backups while saving taxpayer dollars.