What went wrong in June’s flood? Where can Brookfield improve?

According to Director of Public Works Tom Grisa’s memo dated July 11th:

There are numerous reasons for why the City experienced flooding and basement backups during these storms.

The amount and intensity of rain was a major factor. This storm exceeded the City’s design standard of the 100 year storm. The public infrastructure is just not designed to handle the magnitude of this type of storm. In some areas, the City is still in the process of upgrading its systems and we recommend that the City continue to do so in accordance with the approved plans for sanitary sewer and storm sewer improvements.

The City’s storm sewer and ditch system are designed generally to handle a rainfall event of a 10-year design frequency. Ditch enclosures have compromised this system and they should be reevaluated on a case by case basis to see if removal would reduce flooding. After the storm sewer and ditches fill up, secondary drainageways including streets, backyard and sideyard swales, and other drainage courses convey flood waters. These systems should be designed to handle the 100-year event without causing structure flooding. This does not mean however that the flood waters won’t surround a property during such an event.

Power outages for hundreds of properties (up to 5 hours in duration) were a major factor causing sump pumps to not operate leading to flooded basements draining into floor drains resulting in basement backups elsewhere.

Blocked drainage ways, inlets, culverts and storm sewers resulted in flooding of streets and yards. Mulch, branches and mud blocked inlets, culverts and storm sewers. Once these were cleared drainage was typically restored. In some cases structures and landscaping blocked overland drainage paths through drainage easements.

Failed sump pumps for other reasons (not large enough to handle the flow, discharge pipe submerged and could not pump against the high pressure of water, pump burned out, circuit breaker blew, etc.) contributed significantly to flooding of basements and flows in the sanitary sewer system.

The City is still in the process of repairing its sanitary sewer system for leaks and should continue to do so as routine maintenance, just like road maintenance continues each year.

Flow into our sewer system from contract communities of the Fox River Water Pollution Control Center was significantly higher than normal as well indicating they had similar issues as Brookfield. We should continue our work with these communities to tighten up their systems as well.

It appears in some areas underground parking garages were flooded resulting in these flood waters entering the sanitary sewer system and causing basement backups in other locations.

In one instance we had a sanitary sewer pump station fail and the pump did not keep up with the incoming flow. This resulted in basement backups in the area tributary to the station. Staff addressed this failure as soon as we were aware of it and returned the pump station back into service as quickly as possible.

So, 1) a pump failed for a few hours at the Brookfield run treatment facility. It accounts for backups along the tributary to that station. (I’m hoping I can get maps that will help with some of this.)

2) The underground parking garages that are new to Brookfield’s development (thank Mayor Jeff Speaker’s love of dense zoning) caused trouble. In very blunt terms: the new development caused backups for the neighbors. That’s enormously important information the city needs to consider as it approves more high-density zoning projects. Also, the projects may need to be re-engineered so that water from the underground garages goes to the storm sewer system and not the sanitary sewer system.

I hope someone catches this and does something about it very soon. Homeowners have already sacrificed their quality of life as these high density projects have moved next to them. They don’t need sewage in their home as a bonus prize.

3) Failed sump pumps, either from no electricity or other problems, created trouble for neighbors in the same area.

4) Ditches needed for stormwater draining may be compromised where they’ve been filled in over the years. They need to be cleared.

The city has an obligation to improve the areas identified where the city holds responsibility. Homeowners have an obligation, too. About those sump pumps – later today I’ll share Grisa’s review of how every homeowner can protect their property and be a good neighbor.

What happened at last night’s meeting? I’m working to find out.


  1. I’ve been in Brookfield since late 96. We’ve had three hundred year storms since. It might be time to start calling them regular occurrences.

    Brookfield is basically a big swamp. The idea that underground parking structures would not flood is beyond comprehension. My basement is unfinished because eventually a hole in the ground is going to get wet.

    Not that I like it wet. I have two sump crocks, four pumps (and a fifth for emergencies), two marine batteries with alarms to signal when they are in use, a generator, and a separate circuit for backup power. I even have a second discharge outlet for instances when the ditch is too full to pump more into.

    Even so, when the water table rises above the drain tiles, it is hard to pump fast enough. If the water comes in, it goes down the floor drain. Am looking into sump pumps with more horse power, and I’m considering a little backyard retention pond–er, rain garden.

    No sewage here, thank God, but enough to keep us busy.

  2. Not to mention that they need to regularly dredge all the overgrown creeks such as in Beverly Hills Park – that creek has not been dredged in over 12 years. Clearly, Brookfield is not interested in maintenance, just development.

  3. It will be interesting to see how the development of Brookfield East affects the surrounding area which is basically a flood plain. I have heard that different flood planning and documentation is required for developments .5 acres and over. It is also interesting that parts of B.E. are being developed in .49 acre parcels.

  4. Illini – I’ve heard the dredging is held up by DNR permits. Let me know if you’ve heard differently.

    Leapin – what!?! Of course, it’s all nearly approved. If you have details get them out prior to next Tuesday’s council meeting.