By Chris Barlow
Rivers, creeks and streams flow through Wauwatosa, breathing life and vibrancy into our city and enhancing our daily lives. These waterways bring us together and provide beauty, wildlife and a bit of rural scenery to a mostly urban environment.
The ever changing metropolitan setting for this water system creates challenges in flood management and cleanliness which in turn enable us to continue to enjoy their allure. One of the main entities responsible for these tasks is the Metropolitan Milwaukee Sewerage District.
After the Tosa floods of the late 90’s, the MMSD was tasked with assessing what could be done to prevent future disasters from occurring. Floods the size of those 1990’s events are rare, but have a probability of occurrence that ranges from .02 to 1% on any given year. Those percentages are more commonly known as a “100 year or 500 year flood.”
The largest and most publicly visible aspects of this task are the projects on the County Grounds and Hart Park. The strategy employed by the MMSD in these two spots has altered our landscape and changed our city.
“Hart Park used to be about 20 acres,” MMSD Public Information Manager Bill Graffin said. “Through the work we did it is now about 50 acres, and now the park itself stores flood water”
The MMSD began by excavating one foot of soil near the railroad tracks close to State Street and up to three feet of soil near the river bank. After the removal of the soil they put in a levee near the tracks that is made up of a combination of soil and concrete.
The park will remain dry most of the time, but in the event of a flood, the levee will assist in keeping water at bay that could damage homes and businesses. In addition, the efforts should decrease the threat of storm sewer backups that cause basement flooding and sewage overflows.
The houses that were removed from Hart Park after the 90’s floods were not in the flood plane when they were first constructed. Over time development up stream assisted in creating the environment that led to the floods and the damage that resulted.
“Every time you add concrete or asphalt or something nonporous to the ground the rain cannot soak into the ground anymore,” Graffin said “So you’re not capturing water where it falls and that water flows directly into the rivers and streams.”
On the County Grounds, a basin was built that can hold up to 315 million gallons of water. The improvements in this area led to an increase in fauna and wildlife and it sits right next to a 66 acre forest that is managed by the Department of Natural Resources.
“There is about a half mile underground tunnel that takes water from Underwood Creek.” Graffin said “Once the creek rises high enough it spills into an inlet chamber, through the tunnel into the basin.”
Water that is stored in the basin flows into a second chamber that allows it to be released slowly back into the creek. Before this basin was constructed, the water in Underwood Creek used to “slam” into the Menomonee River at a high speeds and that resulted in a very high risk of flooding. The water in the creek flows at a rapid pace due to a concrete base that was installed during the 1960’s.
It was thought at one time that getting the water going very fast was the best way to prevent flooding. As time passed this proved to be the opposite of what occurred.
“The theory was the faster the water flowed it would get out of neighborhoods faster.” Graffin said. “The concrete “supercharges” the flow of water and it gets it downstream quicker.”
The removal of concrete from the County’s waterways began early this century and that included the Menomonee River. In addition to increasing the threat of floods, the concrete bottoms in a creek, stream or river also proved to be a “barrier” that further deadened the waterways. This was due to the fish having difficulty navigating up river because of the lack of vegetation and the speed of the flowing water.
In the Menomonee River 1,100 feet of concrete have been removed in the area south of the Bluemound bridge and extending past Miller Park. In other spots, they have removed barriers that also contributed to the lack of fish making it upstream.
“We naturalized it using rocks, and pools and ripples so that the fish can hang out and rest and then take off and head further up stream,” Graffin said.
The removal of the concrete and now the barriers has resulted in a variety of fish making their way up the water shed. Species such as Salmon, Northern Pike and Trout have been spotted in Tosa and can travel upstream as far as Menomonee Falls.
Flood management was also a focus of the concrete and barrier removal done during the past decade and a half. The water now has a chance to spread out into the soil around the waterways instead of shooting straight through like liquid through a straw. In some cases around the county removing the concrete may not be practical due to buildings that have been built close to the edges.
One of Tosa’s lesser known waterways is Schoonmaker Creek. This creek can be seen running through the Washington Highlands before it dives mainly underground before reaching the Menomonee River. The MMSD did some improvement work near the mouth of the creek also in the name of flood management.
“From the railroad tracks south it was in a culvert for many years,” Graffin said. “We excavated dirt and day lit the creek so that now it meanders from the railroad tracks to the Menomonee in a natural way. “
The MMSD also lowered the topography around the creek and this has reinvigorated and revegetated the area where it flows into the Menomonee. In addition to the flood management, this wetland cleans up the water in a natural process that benefits the rest of the watershed.
Downstream from Schoonmaker Creek on the Menomonee a new pumping station was built in 2010. This facility will assist in abating the probability of basement flooding.
In addition to the work done by the MMSD, the Department of Public Works in Wauwatosa has been busy on the Menomonee River, constructing new storm sewer outfalls. These improvements can be seen near the Menomonee Parkway from Church Street along the river to the north.
“We have been upgrading our system to decrease localized flooding,” Sr. Civil Engineer Maggie Anderson said. “ Some of them are new and some are replacements. The newer outfalls are in connection to the State Street Village Streetscape project (See Page X).”
In the interest of cleaning the rivers, Tosa has seen organizations like the Milwaukee Riverkeepers put together yearly garbage removal projects. The MMSD is designing an “adopt a river” program to enhance the work already being done.
“Companies, organizations or other groups can adopt a stretch of a river,” Graffin said. “They clean it up two or three times a year. We provide the gloves and the bags and pick up all the garbage afterwards.”
Despite all of this effort there is a good amount of garbage that makes its’ way down stream to the harbor and the lake. The MMSD purchased a river skimmer that operates in the harbor and some limited areas of the rivers to alleviate this debris and trash. This device is named Lynyrd Skymmr, which was the result of a naming contest involving the public.
“The band came to Riverside Theatre and someone won a chance to meet them,” Gaffin Said “The boat was there and the band was aware of the name and thought it was very cool. (The skimmer) is great for tourism and giving people a sense that the waterways are clean and not choked with plastic bottles”
The skimmer operates by utilizing a conveyor belt that lowers into the water. It has picked up logs, tires, barricades and event portable toilets. Two people sit at the front of the skimmer and steer garbage and debris onto the conveyor.
Since 1973 Milwaukee County has seen over $150 million in property damage due to flooding. The MMSD and other entities use grants and taxpayer money in the efforts of flood management and river cleanup. The dollars spent is in excess of the previous losses but efforts should lessen the probability of future damage.