Leopold’s Arboretum–It’s Drowning in Stormwater and Needs Upstream Help


One of the questions that this blog asks is how the science and practice restoration ecology is utilized to address environmental issues and restoration opportunities in urban areas.   This blog examines the challenges and opportunities of restoration ecology through the lens of the contested landscape and policy thicket of Madison/Dane County and the Lake Wingra Watershed.   Madison is home of the University of Wisconsin-Madison Arboretum which has a rich legacy in restoration ecology; so this is a good a place as any to test how the profession is doing.

A Case Study

Unhappily, the restoration process locally does not go as smoothly as you might think.  After 80 years, the outcomes in the UW-Madison Arboretum are less than Aldo Leopold had surely hoped.  “Aldo Leopold’s far-reaching vision to restore historical ecosystems at the UW-Madison Arboretum has been difficult to achieve despite ~80 years of restoration work.” Zedler, Doherty, and Rojas, 2014 water-06-00104.

The explanation for this difficulty (as discussed in an earlier blog post here) may be that ecological restoration is not only a technical exercise but also a public policy matter because it involves decisions about how money, land, and labor are utilized.  Authorities and those in power usually get to make decisions about these kinds of things.  Although “negotiations” to resolve these issues are a common practice, there is a vast gulf between the goals of practicing restoration ecologists and what policy makers will allow.  Two recent articles speak to the difficulties of restoration in an urban environment.

Restoration as a Policy Negotiation.

The first journal article, called “A Policy Analysis Perspective on Ecological Restoration” (Baker and Eckerberg 2013) suggests that in a contested landscape with “a dynamic interplay between technical decision-making, ideologies, and interest politics”,  restoration practitioners are forced to “negotiate” about two issues:  1) restoration policy (will restoration be allowed or not); and 2)negotiate restoration targets (what is allowable and what is not), and restoration implementation (are the required resources provided.)  Policy analysis of ecological restoration

Negotiating Human Impacts on Restoration Targets

The second article in the online journal “Water” supports this notion (water-06-00104)  “Leopold’s Arboretum Needs Upstream Water Treatment to Restore Wetlands Downstream”  Zedler, Doherty, and Rojas, 2014).   “The Arboretum  . . .  case study has broad relevance for urban natural reserves.”, say the authors,  who examine and document the Arboretum’s efforts to come to grips with the management of urban storm water.  They show in painful, exacting, and scientific detail how Arboretum leadership lost the negotiations over restoration/land use policy and restoration targets.

The authors trace  the incremental assaults of urbanization in the Lake Wingra Watershed on the Arboretum from the days of Leopold to today.   Zedler, et. al. point out that the impacts of human activities that degrade native vegetation and restored ecosystems are not unique to the Arboretum.  Nature reserves, parks, and biological field stations in urban or urbanizing areas feel the impacts of  storm water.

Impacts of Storm Water

The authors explain how storm water runoff has become the negative impact on the Arboretum and Lake Wingra–an outcome that Leopold and the other Arboretum founders could not have foreseen.  Stormwater is a problem is several ways.  First, stormwater that runs off  across the landscape towards the lake, replaces rainfall that infiltrates the soil and replenishes the groundwater.  This switch in the original functioning of the ecosystem,  alters the hydrological regime.  For example, some areas are too wet when they should be drier and some wet areas are too dry when they should be wetter; the groundwater level drops and springs dry up.   Among other impacts, storm water causes erosion, and it carries sediment, nutrients, and contaminants that alter ecosystem processes, often fueling the establishment of pest species in the place of native vegetation and the transformation of plant communities.

A tragic example of this process in Arboretum wetlands is the takeover of sedge meadows by hybrid cattails em>Typha X  glauca).  In the Arboretum’s Gardner Marsh (pictured below) a remnant sedge meadow is being over run by hybrid cattail which performs as a pest species.  Gardner Marsh

Gardner Marsh on the Arboretum’s SE corner has one of the finest sedge meadow remnants ( green in the middle third of the photo) in the watershed.  Hybrid cattails (brown vegetation in the lower third of the photo) are steadily advancing into the sedge meadow, putting the sedge meadow’s future at risk.  

Negotiating Over Storm Water Management Approaches

The question in the Lake Wingra Watershed, and other urban areas is:  what should society do with its excess storm water runoff?  There are two basic alternatives:  1) encourage rainfall to infiltrate the soil close to where it falls, say, in your backyard or in a city boulevard strip; 2) encourage rainfall to run across the landscape towards the nearest water body, Lake Wingra in this case.  In the first approach officials take responsibility for the impacts of human activities on the environment.  In the second approach, the problem is shifted downstream where it is ignored.

In the Lake Wingra Watershed, city and university officials, and storm water engineers have selected option 2.  Instead of trying to capture and infiltrate rainfall upstream, officials have chosen to transfer the stormwater problem downstream into the Arboretum. This approach has had unfortunate, and unintended negative consequences for the Arboretum and Lake Wingra.  But, as Zedler, et. al (2014) point out, the choice of the easy path through the Arboretum was understandable:  “Open spaces in general, and those on public lands in particular, are priority locations for installing facilities that are easier to build on flat land that has already been purchased for the public good. The Arboretum accommodated a highway and power lines, despite its mission to restore woodlands, prairies and wetlands.”

If that was not bad enough,  as Zedler, Doherty and Rojas (2014) document, the advocates of the engineered storm water management projects installed in the Arboretum often ignored scientific findings plus they dismissed most of  alternative ecological approaches proposed by Arboretum faculty and staff, rejected a restoration-based approach, and did not insist on post project monitoring.  This narrow view of the problem has had disastrous outcomes for the Arboretum, its uplands and wetlands, and Lake Wingra itself.

The engineered storm water management tactic used in the Arboretum resulted in at best, storm water management projects whose outcomes are unknown because follow-up monitoring was not done.  At worst, the outcomes have been counter-productive as in one of the examples cited, Pond #2 in the south-east corner of the Arboretum.  Here, the stated purpose of the project was to capture phosphorous ℗ carried on storm water, settle it out at the bottom of a storm water pond and thus reduce the amount of P entering wetlands and Lake Wingra.   Instead, the authors document through their own research, that Pond #2 is a net exporter of P into the Lake Wingra Watershed.  In other words the storm water pond releases more phosphorous into the watershed than it captures; it is working the exact opposite of the way it was intended.

“At the Arboretum,  attempts to improve water quality have imposed ~10 ha (23 acres) of infrastructure (ponds, armored channels, graded banks, swales) that disturbed the land and allowed weeds to invade and dominate. Weeds are an undesirable and persistent outcome that violates the Arboretum mission.”

As the Zedler et al narrative makes clear, Arboretum leadership lost on both policy counts:  1) restoration was not allowed to inform storm water management solutions; 2) restoration targets were dismissed as less important than building storm water ponds and infrastructure.

Recommendations

Baker and Eckerberg (2013) suggest that restorationists will be well served if they view restoration as not only a technical task but also a social, cultural, and political policy project.  The implication of this view is that If restorationists understand the policy constraints of negotiating restoration outcomes they may add team members with the appropriate skills to operate successfully in the contested landscape.

Zedler, Doherty, and Rojas (2014) suggest that “Insistence on pre-settlement water quality, and treating TSS,(Total Suspended Solids) N (nitrogen) and P (phosphorous) at their upstream sources, would allow the Arboretum to achieve the wetland component of its mission to restore land for research and education, as well as Leopold’s vision of ecosystems restored to pre-European composition.”  They go on to suggest a range of sustainable management approaches that could be used in the Lake Wingra Watershed.

References

Baker, S., and K. Eckerberg. 2013. A policy analysis perspective on ecological restoration. Ecology and Society 18(2): 17. http://dx.doi.org/10.5751/ES-05476-180217.

Zedler, J.B., J.M. Doherty, and I. M. Rojas.  Leopold’s Arboretum Needs Upstream Water Treatment to Restore Wetlands Downstream   Water 2014, 6, 104-121; doi:10.3390/w6010104.

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About Steve Glass

The blogger is a restoration ecologist practicing and writing in the Midwestern United States.
This entry was posted in Aldo Leopold, Cattails, Ecological restoration, Groundwater, Human impacts on restorations, Lake Wingra, Lake Wingra Watershed, Negotiated landscape, Negotiating restoration outcomes, Phosphorus in storm water, Restoration ecology, Restoration in Madison Wisconsin and tagged , , , , , . Bookmark the permalink.

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