Science and Policy Approaches to Managing Urban Hydrology

Most modern urban hydrology management practices focus on storm water, combining elements of flood protection, groundwater recharge³, runoff reduction and protecting natural areas, and are based on widely accepted scientific understanding⁴.

Extreme weather events can produce very high pollutant concentrations during initial phases and can have a thermal impact from the “first flush” of standing water heated by hardened surfaces. Real time sensors used by some jurisdictions evaluate storm water quality to ensure adequate initial treatment, storage and then gradual treatment and release when water quality standards have been attained. Other innovative practices include the use of green roofs that incorporate living plants or pervious⁵ pavement to allow rain and melting snow to percolate through to the subsurface and water gardens. Although best management practices can be easily identified in scientific literature and may be well understood by professional government agency staff, they are less familiar to local officials, citizens and developers who are making everyday land use decisions. A regional database of such practices and an information-sharing network among basin communities could provide an inventory to be used by local public and private decision makers. A U.S. initiative by the National Low Impact Development Clearing House illustrates how this could benefit Great Lakes developers and decision makers, and has particular merit for the binational context of the Great Lakes basin.⁶

The most innovative approaches recognize that successfully managing urban hydrology is more complex than simply managing storm water⁷. By applying concepts of ecological sustainability to land use management, a broader understanding and appreciation can be gained of a locality’s natural processes, impacts and specific conditions. For example, the same commercial development may impact water quality differently depending on where it is located in that basin. Very specific everyday activities, such as the timing and frequency of street cleaning, can also affect water quality. In other cases, so-called best management practices can exacerbate negative impacts if not implemented in ecologically sound ways ⁸. Most local and regional planning efforts fail to adequately link the fundamental relationship between the natural and built environments in this way, and thus inadvertently undermine the region’s precious land and water resources.

In the United States and Canada, urban runoff is managed and regulated through a combination of federal, state and provincial programs implemented at the local level. The U.S. Environmental Protection Agency’s (EPA) overall approach is one of pollution prevention within a larger context of watershed planning. The concept of watershed plans – as contrasted to community plans within city, township or county geopolitical boundary lines – is relatively new. Several planning commissions, councils of governments, and county and township planning boards throughout the region in the U.S. have written and adopted watershed and sub watershed plans. Many involve planning and implementation cooperation among neighboring local units of government. This degree of cooperation demonstrates that storm water management can be effectively addressed as a matter of national or regional policy, and then implemented at the local level using planning and best management practices⁹.

Ontario’s experience of watershed planning represents one of the earliest water resource planning activities adopted by any jurisdiction in North America. Under the Conservation Authorities Act in 1946, Ontario established a system of conservation authorities throughout most of the province. In 1997, the province reaffirmed its commitment to watershed planning after an inter-ministerial review program that commenced in 1994 and culminated in a final report, An Evaluation of Watershed Management in Ontario ¹⁰. The report concluded that successful integrated planning for land and water uses depended on planning for entire watersheds. The importance of watershed management gained further impetus in May 2002, when Justice Dennis O’Connor released theWalkerton Inquiry, Part 2 report ¹¹. This report emphasized protecting the source of drinking water and pollution prevention, based on the premise that poor water quality at the source increases health risks at the tap. To implement the Walkerton Inquiry’s recommendations, Ontario has proposed to establish 24 watershed-based planning areas to develop source water protection plans ¹².

Several policy initiatives in the United States and Canada have explored broad land use issues under the general term smart growth ¹³. Smart growth encompasses a range of land policy and management concepts, including adopting a longer term vision in order to sustain economic and community development, while at the same time protecting the natural environment.

Urban policy issues of greatest relevance to water quality -- land use, transportation and infrastructure -- are also central to managing growth and protecting water resources ¹⁴. Basin jurisdictions developing smart growth strategies and best practices should share these, which might collectively form the basis for future binational cooperation and coordination among local, state/province and federal governments. Future progress under the Agreement, particularly in relation to urban land use, will be further advanced by involving these local governments of Great Lakes cities who have created the programs and policies outlined. Their participation in broader policy and decision-making will recognize their potential role in the achievement of the broader purpose of the Agreement.