Ecorse Creek Flood Control Solutions

Study Approaches

There are many different opinions on how to fix the North Branch of the Ecorse Creek’s flooding problems. The Wayne County Department of Environment is focused on finding the best one. The problems lies in the fact that the North Branch of the Ecorse Creek’s watershed is almost entirely developed, which means there is a lot more impervious surface (roof tops, parking lots, sidewalks, streets, etc.) now than when it was agricultural. There are nearly 46,000 properties from nine different cities within the North Branch of the Ecorse Creek watershed—that’s a lot of roof tops and driveways shedding storm water directly into the drainage system.

An initial screening of all possible flood control measures took place to identify which solutions were viable and warranted further analysis. These initial flood control measures consisted of:

Channel Improvements
Crossing Improvements
Stormwater Detention
Stormwater Diversion
Stormwater Tunneling
Floodplain Management

Based on these concepts, four (4) flood solution approaches for the NBECD were identified, these are:

Storm Water Detention Intensive Approach
Greenway Approach
Tunnel to Rouge River Approach
Tunneling toward Detroit River Approach

Storm Water Detention Intensive Approach Explained

The concept of this approach is to construct many large regional storm water detention facilities along the NBECD. The purpose of storm water detention is to temporarily hold storm water that can not be handled by the drain. This is the water that causes flooding. Once the drain can handle the water after the rain event has passed, the held water slowly drains out of the detention areas down the drain.

A primary advantage of a storm water detention intensive approach is that by temporarily holding excess storm water, the required improvements to the drainage channel and bridges is minimized. The disadvantage is that hundreds of acres of land adjacent to the drain would be required to provide the required volume of storm water detention to effectively mitigate the existing flooding problems. Also, for the Ecorse Creek, providing storm detention alone is not sufficient to solve flooding problems. Improvements to the drainage channel and bridges are also required to convey water into and out of storm water detention facilities.

Greenway Approach Explained

The concept of this approach is to construct large scale channel and bridge improvements to increase flow capacity of the drain thus allowing storm water to rapidly drain to the Detroit River with out large scale flooding problems. A Greenway channel works in such a way that, during normal or low flow situations, water is confined to a very small portion of the overall channel (look at the diagram above). The narrow waterway is designed to maintain a deeper, cooler, and more active water flow than a typical flat-bottom channel. This type of flow creates favorable conditions for fish, waterfowl, and other native species. The larger parent channel only becomes utilized during heavy storm events. During dry periods, this parent channel provides a natural buffer area along the drain. In the event of a heavy rain storm the banks of the normal flow channel would be exceeded causing the drainage system to utilize the larger parent channel to retain and convey storm water. Storm water would then slowly recede back to the normal flow channel once weather conditions improve. The advantage of this approach is that it eliminates the need to use large areas of land for storm water detention facilities and it is cost effective. The disadvantage is the drain has to be substantially widened in areas therefore properties adjacent to the drain must be converted from current use and incorporated into the drainage channel.

Tunnel to Rouge River Approach Explained

The concept of this approach is to construct a large diameter tunnel to collect storm water from the Ecorse Creek and convey it to the Rouge River. In smaller storms, storm water would still go through the Ecorse Creek channel to the Detroit River. In larger events, excess storm water would overflow into the tunnel and be conveyed to the Rouge River. The advantages of this approach are large scale improvements to the channel and bridges are not required. The magnitude of channel widening is much less than the greenway approach therefore it would have less impact on the properties adjacent to the creek. The disadvantages are that this approach costs significantly more than the greenway approach, and it impacts the Rouge River. This approach has higher long term maintenance and channel improvement needs. In addition, environmental impacts on the Rouge River would need to become a part of this project and easement and property acquisition for building the tunnel and it access shafts would be needed.

Tunneling toward Detroit River Approach Explained

The concept of this approach is to construct a large diameter tunnel parallel to the drain to collect storm water from the upper reaches of the Ecorse Creek and convey it toward the Detroit River. In smaller storms, storm water would still go to through the Ecorse Creek channel to the Detroit River. In larger events, excess storm water would overflow into the tunnel and be conveyed toward Detroit River. The advantages of this approach are that large scale improvements to the channel and bridges are not required. The magnitude of channel widening is much less than the greenway approach therefore it would have less impact on the properties adjacent to the creek. A disadvantage is this approach costs significantly more than the greenway approach. Similar to the Rouge tunnel approach, this also has higher long term maintenance and channel improvements needs and easement and property acquisition for building the tunnel and it access shafts would need to done.