Estabrook Dam Removal


Milwaukee Riverkeeper has joined with citizens, fisherman, property owners and elected officials to call for the removal of the Estabrook Dam. Removing the dam will save millions in taxpayer money, alleviate flooding, and improve water quality and habitat for fish and wildlife.

Milwaukee County built Estabrook Dam in 1937 in order to elevate water levels for recreational purposes. Its construction required both the blasting of bedrock upstream and river straightening to reduceflooding. The Dam has 3 parts: a gated section (with “sharks teeth” that capture woody debris and protect dam gates); the spillover section, which acts like a waterfall when the dam is closed; and an island that the gated and spillover sections rest upon. Historically, the Dam was closed during summer months and opened from fall through spring.

Over time, Milwaukee County failed to maintain and repair the Dam per State Dam Safety regulations. In 2009, due to hazardous conditions created by the ill-maintained structure, the Wisconsin Department of Natural Resources (WDNR) ordered the County to open the Dam gates until the County repaired or abandoned the Dam. The original deadline for this work was July 27, 2012, which was subsequently extended by WDNR to December 31, 2014 and again until December 31, 2016.

Since the County was not obeying DNR orders, Milwaukee Riverkeeper sued Milwaukee County for failure to operate and maintain the Dam in good working condition, and in 2012, the Milwaukee County Circuit Court declared Estabrook Dam a public nuisance. The County prepared an Environmental Assessment (EA), which identifies and analyzes the alternatives available to address the Dam, including repair, a rock ramp alternative, or removal of the Dam. The alternative the County chooses must comply with both the WDNR’s repair/abandon order and the Milwaukee County Circuit Court’s order to remedy the nuisance. If the County chooses an option that does not comply with these Orders, Milwaukee Riverkeeper will go back to the WDNR and to the Court to advocate for a remedy that fully abates the nuisance.


What is the current status on removing the Estabrook Dam?

On October 3, 2016, Milwaukee County Executive, Chris Abele, City of Milwaukee Mayor, Tom Barrett, and Milwaukee Metropolitan Sewerage District (MMSD) Executive Director, Kevin Shafer, announced a plan to move forward with finally removing the Estabrook Dam.

Milwaukee Riverkeeper was supportive of the plan for two reasons:

  1. the plan gives control of the Estabrook Dam, which increases flood risk to hundreds of upstream properties, to the federally designated flood management authority for the area (MMSD), and
  2. the plan will involve only temporarily transferring land from one public entity to another, which after dam removal is finalized, will be transferred BACK to Milwaukee County as public park land and will be rezoned as park by the City of Milwaukee.

After the plan was announced, Milwaukee County sold the dam to MMSD, which required the approval from the City of Milwaukee. As owners of the dam, MMSD applied for a demolition permit, after soliciting input from the public. MMSD has since received all permits to move forward with the removal of the Estabrook Dam. Construction is scheduled to place between February and June of 2018.

Why is an Environmental Impact Statement being conducted?

The Environmental Impact Statement (EIS) is an important step in the environmental decision-making process that should not be ignored. Dams are regulated by the Wisconsin Department of Natural Resources (WDNR). The WDNR issues an operational order or permit to any dam operator in the state. To issue an operational order, the WDNR is required by law (Chapter 31 of Wisconsin Statutes) to prepare an EIS. In other words, regardless of the alternative chosen by the County, the WDNR will need to prepare an EIS before issuing an order allowing the County to operate or remove the Dam.

The WDNR completed it’s EIS on the Estabrook Dam in early April 2017. Unfortunately, the WDNR failed to consider removal as a reasonable alternative to repairing the Dam.

It should also be noted that Milwaukee County may also need Army Corps of Engineers and FEMA approvals for any major project affecting wetlands or water levels during flooding events, which would also likely require an Environmental Assessment.Furthermore, the EIS contains helpful, scientific data and facts to provide a road map for the County to make an informed decision, rather than one based on emotion or politics.

What are the benefits of removal versus repair?

a) Water Quality

The Dam causes major water quality problems. Dams impound or back up water upstream, which can increase water temperatures. Warm water holds less oxygen than cold water, whichharms fish and other aquatic life. Warm water, in combination with excess nutrients, exacerbates algae growth. When algae are broken down naturally in the stream by bacteria, more oxygen is consumed, which can decreaseoxygen levels.This segment of the Milwaukee River (as well areas north to Cedarburg and south to Lake Michigan) is part of the Milwaukee Estuary “Area of Concern,” designated as such in 1987 due toharmful historical modifications and pollutants that are considered toxic contaminants.

b) Sedimentation

Sediment is another concern. Dams cause sediment to build up in the impoundment area, which can negatively affect fish and mussels. The lack of sediment moving downstream of a dam starves downstream areas of sediment needed to create riparian habitats, sandbars, floodplains, and other river features. Eventually, an impoundment will fill up with sediment, impairing water quality and recreational use,andmust be dredged, which is very costly.

Historically, the County operated the Estabrook Dam by opening and closing the gates on a seasonal basis (open in the fall and close in the spring). When the gates were open, large amounts of sediment would be flushed downstream in one big release rather than slowly over time. These large volumes of sediment can cause harm to fish eggs, mussels, and other aquatic life downstream. While some sediment movement is natural and essential to create riparian habitat and to provide nutrients to downstream areas, these large flushes are unnatural and negatively impact the river system.

Sedimentation over the years has made the impoundment very shallow, even prior to 2009 when the Dam was ordered open. This can worsen water temperature and oxygen issues, as the depth of water column decreases in the impoundment.

c) Fish impediment

Impediment of fish passage is another harm caused by the Dam. Removal of the Dam would allow fish to swim upstream to spawning habitats. Healthy and sustainable fisheries are important to paddlers, fishermen, and the community at large. Ozaukee County spent over $8 million upstream to improve fish passage, and the removal of Estabrook Dam would expand the benefit of those projects.

d) Unnatural Water Levels

The historic Dam operations created unnatural water level manipulations. These abnormal seasonal fluctuations can cause “dry out” or “freeze out” of amphibians and other aquatic life that live in the impoundment. They lay their eggs along the shallow shoreline area and when that water disappears with the opening of the gates, the eggs or individuals dry and/or freeze. While the impoundment creates seasonal and limited recreational opportunities, it also increases flooding on properties located upstream of the Dam and within the Milwaukee River floodplain.Removing the Dam would also restore the natural and wild aspect of the Milwaukee River in the Estabrook and Lincoln Park areas.Overall, the ecological health created by a free flowing river offers greater long term value than maintaining the impoundment.

e) Recreation

Recreational opportunities, such as, paddling and fishing would be improved with Dam removal. Removing the Dam would eliminate motorized boating, however it would also remove safety hazards for other recreational uses such as swimming, fishing, kayaking and canoeing.

f) Cost

The estimated cost of repair ($5.13 Million) is three times the estimated cost of removal ($1.67 Million). Why? (see question 5 below).

Why do people want to keep the dam?

The majority of people do not want to keep the Dam. A small group of upstream homeowners have formed a group called MRPA or the Milwaukee River Preservation Association, and they are a vocal minority. They believe their housing values will be negatively affected by dam removal. In addition, several of these homeowners own motorized boats that they have historically usedon the impoundment. Dam removal would make it difficult to use most motorized boats due to lower water levels. Non-motorized navigation by canoes, kayaks, and other small watercraft would still be possible seasonally, similar to upstream and downstream sections of the Milwaukee River. While the number of affected homes in the impoundment has been stated as around 300 during public meetings, the vast majority of those homeowners would like to see dam removal due to the flood risk posed by the Dam and the requirement to purchase expensive flood insurance due to Federal FEMA regulations. These voices are being drowned out by MRPA’s loud (and often false) claims.

How much does dam removal cost versus repair?

The table below includes the estimated costs associated with various options for the Dam. These were taken from the EA and developed by AECOM.

Alternative Estimated Capital Cost Estimated Annual Operations and Maintenance Cost Total Present Worth Estimated Cost (assuming 20 year life expectancy)
Dam Removal $1,674,000 $0 $1,674,000
Rock Ramp Option (gate section removal and 6.3 ft. high rock ramp constructed) $2,419,000 $55,000 $3,318,000
Dam Repair $2,518,000 $160,000 $5,134,000

The estimates in the table are 3 times higher to repair the Dam than to remove it. The operation and maintenance costs for repair do not include administrative costs associated with state and federal permitting, nor future dredging costs when sediment builds up in the impoundment. The repair option also does not include a realistic cost for fish passage. Leaving a few gates open does not mean that the fish will be attracted to those areas or that they will be able to swim upstream as proposed by MRPA.The EA states that repairing the Dam now will provide an approximate 20 years of additional use with proper operation and maintenance. The Dam will be nearly 100 years old at that time, rehabilitation costs are anticipated to grow, and rebuilding of the Dam will likely be the next option.

Is dredging considered as part of removal costs?

The WDNR is just starting the second phase of a dredging project to remove contaminated sediments (from legacy industrial activity) upstream of the Dam. The first phase of the project was completed several years ago to clean up the lower portion of Lincoln Creek and the western oxbow of the Milwaukee River in Estabrook Park, as well as an earlier cleanup near Blatz Pavillion. These projects were funded by the US EPA as a part of the Great Lakes Legacy Program and concentrated on hot spots of contamination. The dredging was not aimed at increasing depth of water for motorized navigation.

Dredging to enable navigation was not included in the EA. If the Dam were repaired, there would likely be dredging costs for sediment removal in the near future in order to keep it open for motorized boat recreation. The costs associated with the continual maintenance and operation of the Estabrook Dam is a poor use of taxpayer money. The best option is to return the river to a natural, free-flowing state.

What are the structural and operational problems of the dam?

The most recent repair/abandon order from the WDNR in 2009 goes into significant detail about the structural problems of the dam in the “Findings of Fact” section of the Order, which is what we are relying on. This Order also identifies work that still needed to be done from 1995, 2004, and 2008 Dam Safety Inspection reports. Aside from the structural problems of the Dam, the original design and operational procedures for the Estabrook Dam are not good for the environment. Extremeincreases and decreases of water levels on a river or a lake wreaks havoc on the ecosystem as a whole. At the time it was constructed, the dam gates were not supposed to be opened and closed each season, despite how the County operated it historically. While some seasonal fluctuation in water levels is normal, the water level variability caused by draining the impoundment is not normal and is harmful. The Dam is an old, outdated structure that does not improve water quality or wildlife habitat. It wastes taxpayer money that could be spent on more worthy infrastructure improvements.

Does the dam structure reduce or cause flooding?

There is a widespread misconception that the Estabrook Dam helps to prevent flooding upstream; it does quite the opposite. Dams raise water levels upstream. During smaller to medium storms, the gates were sometimes opened to drop water levels upstream to alleviate potential flood risk that causes biological damage, as detailed above, as well as safety concerns for paddlers and fishermen. During more severe storm events, like the 100-year storms and greater, the Dam gates are usually underwater and not useful for flood management.

A new hydraulic analysis by the Southeast Wisconsin Regional Planning Commission (SEWRPC) has shown that when the Dam gates are closed, flood risk increases upstream. In a 100-year storm, water elevations would be increased by up to 1.5 feet at the Dam. Historically, the County has not employed or designated a dam operator and there were problems opening and closing gates during heavy rains. If the County waited too long, it was impossible to open the gates due to the pressure from the water. WDNR’s current operational order requires the County to only drain 6 inches of water at a time, although the County has not operated the Dam in that way. Several of the gates have not worked properly for years.

Hypothetically, if the County Board decides that the existing policy to repair the dam will stand, then the County will need an operational order from WDNR. That process will determine how the dam will be operated in the future. It is unlikely the DNR will allow the County to operate the dam the way that it did historically due to the damage that gate opening and closing causes to the river and wildlife. In other places in the State, the WDNR has been requiring “full pool” impoundments, meaning that the gates would have to remain closed permanently except during rain events. If the gates were closed permanently, flooding would become an even more significant issue for the homeowners on the impoundment and upstream. Milwaukee County could also be liable for future flood damage if the Dam gates were not opened in a timely fashion during major storm events. Flood insurance premiums are higher for upstream residents as a result of the Dam. Removal of the Dam would likely decrease those premiums.

Does the dam help to replicate the original condition of the Milwaukee River?

Prior to the original construction of the Dam, the river had higher water levels. Blasting of bedrock and the straightening of an “S curve” upstream to alleviate flooding, decreased the flow of the river around the Dam area. The Dam was constructed to increase water levels; however, no lake existed above the Dam historically. The river was a narrow, deep channel that was surrounded by wetlands that would flood during heavy rains.

Dam removal will not return the river to its original state, but repair doesn’t best replicate the original condition of the Milwaukee River either. No alternative currently under consideration by Milwaukee County would do that. Removing the dam will restore the river to a natural condition and to a free-flowing river. A natural state that is the most protective of water quality and wildlife habitat includes removal of the dam.

What will happen to the sediment accumulated in the impoundment?

As mentioned above, the WDNR has done extensive dredging of contaminated sediments as a direct result of the build-up of sediment. For 6 years, the DNR dredged more than 175,000 cubic yards of contaminated sediment upstream of the dam at a cost of $49 million. If the Dam were removed, water levels would not be expected to change significantly from what they are today (and have been since 2009). Efforts to remove non-native invasive vegetation and encourage re-establishment of more desirable native vegetation would likely be required. There are also legacy piles of debris from the Dam that are unsightly and have been stacked next to the dam for years, if not a decade or longer. There are several groups that could help with this effort, as well as funding sources that could help finance this work, but none have been willing to fundraise without knowing the ultimate fate of the Dam. Significant restoration and shoreline restoration should be a component of any alternative.

What about current development and property owners?

It is true that past development has occurred based on the water level created by the dam (which is not the original river water level or river location), but that shouldn’t negate taking a hard look at this dam to determine the best outcome. This includes not only the cost to fix it (which is three times higher than removal), the maintenance required (which currently doesn’t consider sediment dredging and other costs), and the likelihood that within the next 20 or so years, the County will have to take it out or rebuild it, and incur significant capital costs due to its limited life expectancy. Maintaining the dam will also bring continued environmental impacts and flood risks.

Not every dam can or should be removed, but it makes sense to take a fresh look at the facts and make a reasoned decision. It does not make sense to spend millions to fix this dam, given the maintenance problems that are likely to continue, to only have to spend millions more in the near future on more repair costs, rebuilding, or removal of the dam. Instead, it is best to get on with the restoration work now and try to lessen impacts to existing infrastructure. Restoration will improve access to the river which will increase the area’s recreational use as well. Arguably, the water level after removal of the dam will likely be the same as it is today with the gates open. Removal of some of the contaminated sediments will also help with navigation for human-powered craft.

Documents & Additional Resources


Estabrook Dam Repair Order, July 2009
Estabrook Dam Municipal Dam Grant, October 2009Full position paper on Estabrook Dam
The following groups signed on to Milwaukee Riverkeeper’s position paper calling for the removal of the Estabrook Dam in Glendale:
Sierra Club Great Waters Group
Trout Unlimited-Southeast WI Chapter
Milwaukee Steelheaders
Milwaukee Lake and Stream Fly Fishers
Milwaukee County Conservation Coalition
Greater Milwaukee Green Party
Glendale Natural Areas Group
Riverwest Neighborhood Association

Do you live in the floodplain?

Click here to view this map in Google Maps (type your address into google maps to see if your property lies in the floodplain)

1) When google maps opens, simply type your full address into the search bar at the top of the screen and then click the little magnifying glass next to the search box.

2) A placemark will appear on the map; use the ” ” and “-” buttons on the bottom right corner of the map to zoom in and out, and click the map and drag your mouse to pan across the map.

3) You can turn the 2 layers (100 yr flood and 500 yr flood, located in the upper-left portion of the screen), by checking and unchecking the checkbox next to the layer name.

The Parks Department is very understaffed right now and it has been for years. The Parks Department is in charge of operating the Dam, and they have said they cannot ensure that there will be a staff person available during a storm to open the gates. They are calling for removal. The Parks Department has concerns about how the Dam has been operated in the past and how it will be operated in the future. A responsible policy would take into account the limitations of the staff. Based on the facts, removal is best for the river and the community as a whole in order to avoid these issues related to flooding and the operation of the dam.