Water & Infrastructure in the ReFresh Milwaukee 2018 Progress Report
Briant Novinska-Lois, Community Engagement & Education Graduate, University of Wisconsin Milwaukee
(Current Master Student in City & Metropolitan Planning, The University of Utah)
ReFresh Milwaukee 2018 Progress Report/Photo citation: https://city.milwaukee.gov/ImageLibrary/Groups/cityGreenTeam/documents/2018/ReFresh2018ProgressReport.pdf
Introduction
The ReFresh MKE Plan (2013) sets forth ambitious environmental sustainability goals to preserve and/or improve the integrity of the surrounding natural environment, in order to meet the needs of current and future generations of Milwaukeeans and invigorate the local economy. This approach is congruent with the definition of sustainable development in Planning for Sustainability: Creating Livable, Equitable, and Ecological Communities: “Sustainable development is development that improves the long-term health of human and ecological systems” (Wheeler, 2005, p. 24). With keeping the maxim of sustainable development at the fore, the local government of Milwaukee aims to reduce stormwater runoff (from increasingly devasting rainfall events), which damage the immense historic and economic value of surrounding bodies of water in the greater Milwaukee area.
In the ReFresh MKE Plan (2013), several important topic areas have been decided upon, such as buildings, mobility, energy, resource recovery, food systems, water, human capital, catalytic projects, land and urban ecosystems, and implementation (p. 5). In a quick glance of the topic areas and subsequent goals of the ReFresh MKE Plan, it provides the impression that they were chosen to support the definition of sustainable development previously mentioned, in that they focus on balancing natural ecological structures and systems with the continuation of human activity and health. As for the purposes of this research paper, the topic of “water” in Milwaukee’s ReFresh MKE Plan has been chosen for further investigation.
In regard to the specificities of water, the ReFresh MKE plan has set goals to protect Milwaukee’s fresh water supplies, which come from nearby Lake Michigan and interconnecting rivers and estuaries. This is incredibly important to the city of Milwaukee’s local economy, as these bodies of freshwater provide the city access to an astounding $483 billion [water] market (ReFresh MKE, 2013, p. 61). Included in these water-related goals are plans to: “Reduce stormwater runoff and clear water from entering sewer system”; “Achieve swimmable and fishable waters in Milwaukee watersheds and the near shore of Lake Michigan”; “Establish Milwaukee as America’s Water-Centric City”; and “Prevent new Aquatic Invasive Species (AIS) from entering Lake Michigan and Milwaukee area waterways” (p. 63).
In this paper, the goal to “reduce stormwater runoff…” will be the subject of specific investigating in order to determine its efficacy and possible room for improvement. One strategy to mitigate the detrimental effects of stormwater runoff that the city of Milwaukee seeks to implement is green infrastructure (ReFresh MKE, 2013, p. 64). Some of the green infrastructure recommendations will be incorporated through the Green Street Stormwater Management Plan (n.d.). In 2008, according to this plan, city ordinances were passed to allow green infrastructure, with pilot studies and projects taking place between 2008 and 2011 (slide 2). Priorities of the Stormwater Management Plan are to implement “green space where available” and “incorporate innovative pavement types” (slide 3). Since concrete is impermeable to [rain] water, green space in Milwaukee is seen as key to limiting the disastrous effects of flooding, as up to 25% of the city consists of concrete streets (slide 5). Some suggested green space techniques included in the Stormwater Management Plan are vegetated medians, terraces, and street-adjacent open spaces (slide 4). Specifically, techniques include planting trees that allow for drainage to occur at a quicker rate, as well as pavement surfaces and structure that allow water to pass through or drain faster (i.e. porous), such as streets and alleys that include brick-type materials, as opposed to solid concrete (slide 4). These strategies will have the added benefit of not only limiting flooding events (that cost hundreds of thousands of dollars to property owners), but also improving water quality, as there would potentially be less pesticide, fertilizer, or industrial runoffs from surrounding farms, residential properties, and factory sites. Furthermore, specific green infrastructure that the ReFresh MKE plans wants to implement through the Stormwater Management Plan include “bioretention in medians, tree trenches, and bioretention in terrace grass or natural landscaping” (slides 8-10).
Another green infrastructure intervention are bioswales. The City of Milwaukee Common Council passed the Green Infrastructure Plan, which lays out the implementation of techniques and strategies that increase green space throughout the city and region. One of those techniques include installing bioswales, which are “… vegetated or mulched channels that provide water treatment and retention as they move stormwater from one place to another. Vegetated swales slow, infiltrate, and filter stormwater. They are particularly suitable along streets and parking lots due to their linear shape” (City of Milwaukee Green Infrastructure Plan, June 2019, p. 23). Bioswales offer an intriguing green, low-cost alternative to grey infrastructure in channeling stormwater runoff, in that they have the potential to create jobs (building & maintenance), increase property values, reduce instances of crime by their inherent design, create recreational and educational opportunities, and improve water, habitat, & air quality (p. 21).
The purpose of this paper, then, is to explore and answer two questions with relevant data, findings, and cases(s): 1) Since Milwaukee’s Green Infrastructure Plan dictates that installed green infrastructure needs to catch at least ½ inch of water per rain event (p. 13) are these bioswales sufficient enough to accomplish this stormwater runoff mandate and limit the intensity of flooding events that occur in the future? And 2) if bioswales appear to be sufficient tools in limiting the effects of harmful stormwater runoff and the ill effects of stormwater flooding, how should Milwaukee move forward in leveraging this inexpensive intervention that is both economically and environmentally beneficial?
Problem
Milwaukee is experiencing 50- and 100-year flood events, not every 50 or 100 years, as one might expect, but every, to every other, year. Significant flooding events have occurred most recently in Milwaukee in 2018 and 2020, which dropped upwards of an inch of rainwater in a short amount of time, about 24 hours (Kuffel, Jun. 14, 2020). These disastrous flooding events are becoming more and more common and increasingly intense as weather patterns are interrupted due to global warming and subsequent climate change. Essentially, the problem is massive amounts of [rain] water being dropped too quickly, which has a one-two punch effect: infrastructure that is designed to drain stormwater cannot clear the rainwater fast enough, which overwhelms the sewage systems. This is due to the fact that the primary drainage infrastructure is grey infrastructure consisting of impervious materials, such as concrete, which currently constitutes 47% of Milwaukee’s surface area (City of Milwaukee Green Infrastructure Plan, Jun. 2019, p. 26). This, in turn, results in rain and sewage water backing up and saturating the surrounding soils, which magnifies the effects of flooding that are caused by rainfall events in the Milwaukee area.
Solution
There is mounting evidence that demonstrates the effectiveness and urgency to install green infrastructure in all types of communities, but especially that such installation needs to occur in urban communities given the concentration of grey (impervious) infrastructure and pollutants in these types of environments. The data below (included in the appendix) demonstrates how bioswales have the ability to filter and/or absorb toxic compounds and elements in the soil after a rainfall event, which would normally accumulate in the soils of urban environments. Other data included in the appendix, but specifically this data/example alone, underscores the importance of how green infrastructure can mitigate the harmful effects of toxins that can cause adverse health effects for urban dwellers. as well as other general information regarding the advantages, disadvantages, costs, and purposes of bioswales. There has been evidence to suggest that bioswales in particular are especially suited to reduce the impacts of stormwater runoff, which harms Milwaukee’s valued waterways. It has been cited by the American Society of Landscape Architects (ASLA) that a bioswale the size of just 4 square meters can reduce stormwater runoff by as much as a 25 percent (ASLA, n.d.). These are incredible results, especially given the fact that bioswales are inexpensive to install, easy to maintain, and increase property value. Such metrics also become especially important given that Milwaukee’s average amount of rainfall per year is 88.42 centimeters (The Weather Channel, n.d.), with about 126.7 days of rainfall (Weather Atlas, n.d.). This averages to .697 centimeters per rainfall event, or a little more than a quarter inch of rain (.27 inches). Given that the Green Street Stormwater Management Plan mandates that ½ inch of stormwater must be collected per rainfall event, aggressive installation of bioswales seem like the logical response.
Data Collection Profile
The two cited cases in this paper are related to storm water. In the first case Anderson, B. S., Phillips, B. M., Voorhees, J. P., Siegler, K., & Tjeerdema, R. (2016), storm water is collected and analyzed, and the effectiveness of bioswale implementation is assessed to determine how well such implementations intervene in lessening storm water toxicity and output. Sites where data was collected were from residential and commercial areas over a two-year period in Salinas, California. In the second case, 8 neighborhood sites were assessed to gauge the public attitudes towards and various aspects of bioswales (both good and bad) in Portland, Oregon. Attitudes were gathered through in-person interactions between researchers and 45 residents in these sites.
At these sites, during three, separate storm events, it was demonstrated that bioswales captured a staggering amount of the stormwater toxins that would have been released into waterways and drinking water. Specifically, the bioswales significantly reduced toxins by 29% to 100% of the output water samples (Anderson, et al. 2016, p. 3131). This is due, in part, to the capacity that bioswales have in retaining stormwater, which effectively prevents toxins from leaching, as cited above.
Strategy
Within the city limits of Milwaukee, there are just short of one dozen officially designated bioswales. The actual count of bioswales is totaled at 11, according to “Existing Green Infrastructure Strategies” (City of Milwaukee Common Council, MMSD, City of Milwaukee DPW, City of Milwaukee DNS, Fund for Lake Michigan, The Brico Fund, . . . Tom Barrett, 2019), and is plotted on the map included in the appendix below. There seems to be a strategy to how these bioswales are placed: 8 of the 11 officially mapped bioswales lay within the boundary of the watersheds just underneath the city of Milwaukee. This would enable or position the bioswales to absorb most of the stormwater run-off before reaching watershed depths and prevent consequential flooding from occurring.
Now, given that these watersheds cover a significant area underneath the city and county of Milwaukee, it would be prudent of the Milwaukee region to greatly bolster the number of bioswales within these areas. Specifically, the watersheds underneath the city and county of Milwaukee are the Kinnickinnic River basin, the Menominee River basin, and the Milwaukee River basin (south branch). These river basins combined equal an area of about 337.37 square miles. As cited above, a bioswale that is about 4 square meters in size (about 43 square feet) can absorb25 percent of fallen stormwater, which would mee the required efficacy benchmark laid forth by the ReFresh MKE Plan (with the Green Infrastructure Plan) and the Green Street Stormwater Management Plan. As 1 square mile is equal to 27.8 million square feet, 648,334 green bioswales could fit within the city and county of Milwaukee’s watersheds and river basins. As placing nearly 700,000 bioswales is not at all feasible, it is, then, much more reasonable to attempt in spreading them out. As the city of Milwaukee becomes increasingly concrete the closer to the city-center one gets, and since concrete is impermeable to water, it would make more sense to place these bioswales here, such as in parks (Lake Park, Veterans Park, Washington Park, King Park) and along the Milwaukee River. Additionally, the city of Milwaukee, and the state of Wisconsin, can offer homeowners take incentives to install their own bioswales, as they would also likely increase their property values.
Conclusion
The value of bioswales, as a green infrastructure, is immense. Not only do bioswales have the potential to increase property values, lower crime rates, improve air quality, reduce toxins in water, and generally appear more pleasant than concrete structures, they can also provide cities/municipalities and property owners with an inexpensive and low-maintenance strategy to reducing their risk of flooding events (Core Themes and Sub-Themes developed from coding interview transcripts, Everett, G., Lamond, J., Morzillo, A., Matsler, A., & Chan, F, 2015). As flooding is a major concern for the continued integrity of waterways in the Milwaukee region (as evidenced by the increasing occurrences of heavy rainfall events), it is imperative, then, that the city and county of Milwaukee greatly bolster the number of bioswales in the area. The city and county of Milwaukee would benefit the most by placing more bioswales in areas with high concentrations of grey infrastructure and providing monetary incentives to Milwaukeeans to install bioswales of their own.
Appendix
“Sensitivity of Hyalella azteca and Chironomus dilutus: LC50s and EC50s used to calculate toxic units (TUs) for selected chemicals detected in storm water”,
Anderson, B. S., Phillips, B. M., Voorhees, J. P., Siegler, K., & Tjeerdema, R. (2016).
“Hydrology results from three storm events”,
Anderson, B. S., Phillips, B. M., Voorhees, J. P., Siegler, K., & Tjeerdema, R. (2016).
“Percent reduction of concentrations and contaminant loads* of select chemical classes”,
Anderson, B. S., Phillips, B. M., Voorhees, J. P., Siegler, K., & Tjeerdema, R. (2016).
“Toxicity and chemistry of bioswale inflows and outflows monitored during three separate storms”,
Anderson, B. S., Phillips, B. M., Voorhees, J. P., Siegler, K., & Tjeerdema, R. (2016).
“Core Themes and Sub-Themes developed from coding interview transcripts”,
Everett, G., Lamond, J., Morzillo, A., Matsler, A., & Chan, F. (2015)
“Existing Green Infrastructure Strategies”,
City of Milwaukee Common Council, MMSD, City of Milwaukee DPW, City of Milwaukee DNS, Fund for Lake Michigan, The Brico Fund, . . . Tom Barrett. (2019).
Citations
Anderson, B. S., Phillips, B. M., Voorhees, J. P., Siegler, K., & Tjeerdema, R. (2016).
Bioswales reduce contaminants associated with toxicity in urban storm water. Environmental Toxicology and Chemistry, 35(12), 3124-3134. doi:10.1002/etc.3472
City of Milwaukee Common Council, MMSD, City of Milwaukee DPW, City of Milwaukee DNS, Fund for Lake Michigan, The Brico Fund, . . . Tom Barrett. (2019).
City of Milwaukee Green Infrastructure Plan (pp. 1-70, Publication). Milwaukee, WI: City of Milwaukee.
Eco City of Milwaukee, W. (n.d.). Green Infrastructure. Retrieved October 04, 2020, from
https://city.milwaukee.gov/eco/WCC/GI
Everett, G., Lamond, J., Morzillo, A., Matsler, A., & Chan, F. (2015). Delivering Green Streets: An exploration of changing perceptions and behaviours over time around bioswales in Portland, Oregon.
Journal of Flood Risk Management, 11. doi:10.1111/jfr3.12225
Howard, M., Mason, M., Adams, L., Buford, E., Campbell, M. C., Cole, P., . . . Polenske, J. (2013). ReFresh Milwaukee (pp. 1-106, Publication). Milwaukee, WI: City of Milwaukee.
Kuffel, S. (2020, June 14). Extreme flooding: Exploring Wisconsin’s growing problem with flood-producing rains. Retrieved October 04, 2020, from
Milwaukee River basin. (n.d.). Retrieved October 29, 2020, from
https://dnr.wisconsin.gov/topic/Watersheds/basins/milw
Milwaukee, WI Monthly Weather Forecast. (2020, November 01). Retrieved November 01, 2020, from
https://weather.com/weather/monthly/l/39.6440,-104.9826
Professional Practice. (2020). Retrieved November 01, 2020, from
https://www.asla.org/bioswales.aspx
Yu Media Group, Weather Atlas. (n.d.). Milwaukee, WI – Detailed climate information and monthly weather forecast. Retrieved October 30, 2020, from
https://www.weather-us.com/en/wisconsin-usa/milwaukee-climate