Managing Water Resources


Over 30 years ago, I began working for the City of Baltimore’s Water Quality Management Program[1]. One of my first projects was working on a monumental study of the nation’s urban waterways, the Nationwide Urban Runoff Program (NURP). Under this program, the Jones Falls was one of 28 watersheds, nationwide, selected to investigate the water quality of urban runoff and examine the performance and effectiveness of mitigation-focused management practices. The results demonstrated the intractable nature of urban runoff pollution and the few management options available to control it.

Reveling in their success in regulating the point source community, the U.S. Environmental Protection Agency (EPA) deliberated over the NURP results for almost a decade before deciding to shift gears and exercise their authority to focus on diffuse pollution from urban areas. This led to the Clean Water Act amendments of 1987 which resulted in a comprehensive national program for addressing stormwater discharges. In the early 1990’s, municipalities with separate storm sewer systems (MS4) such as Baltimore were issued 5-year permits that required the control of stormwater through programs such as capital improvements (e.g., wetland creation), public education, stormwater runoff control from development sites, and sediment and erosion control.

Runoff Simulation
Baltimore NURP Study: Simulating urban runoff. JHU School of Public Health with Dr. Vincent Olivieri

In the early years of the permit program, permitees were required, among other things, to focus considerable effort in characterizing the quality of urban runoff through monitoring studies. These studies, at least in theory, were designed to help provide the basis for prioritizing remedial actions such as stream restoration and constructed wetlands. This later led to studies designed to determine the collective effectiveness of best management practices (BMPs) at a watershed scale. Unfortunately, not enough time or scientific rigor was put towards this effort and science became the enemy of progress in meeting the restoration goals for our waterways. Implementation became the cry from the impatient public, which was heard clearly by policymakers and regulators.

The City of Baltimore and other jurisdictions heard this cry and as a result, they have implemented millions of dollars worth of BMPs including stormwater wetlands, bio-retention, street sweeping and stream restoration. However, the rationale for deciding how many and what kinds of practices would satisfy permit conditions was not clearly established. While undoubtedly the results of these projects have had some benefit to local waterways, there is no standardized yardstick for measuring this benefit. As a result, the quality of our waterways has continued to decline despite the best intentions of the MS4 program.  

Bioretention Cells
Bioretention cells with tree-planter box drains in Baltimore City intercepts and “treats” stormwater

An underutilized program of the Clean Water Act could be the key to making the MS4 permits more effective by developing consistent performance standards that are tied to water-quality based outcomes. State environmental agencies are required to identify “impaired” waterways and establish standards to determine the maximum amount of pollution that each waterway can assimilate without exceeding standards. This measurement is known as the Total Maximum Daily Load (TMDL). TMDLs exist for tens of thousands of water bodies across the nation but, ironically, few plans have ever been fully implemented leading to attainment of a given TMDL.

That is changing. Today, the new paradigm for MS4 permitting in the State of Maryland is the incorporation of TMDLs within the MS4 permits, thereby requiring the permittee to develop an implementation plan and schedule for reducing contaminants and meeting the TMDL. This should eliminate the rather haphazard manor at which restoration efforts have been implemented and provide a standard yardstick for measuring progress. Much more is needed however, to meet our water quality goals and protect our waterways from urbanization.

Not only have restoration efforts been hampered by a consistent standard for gauging its success, the MS4 Program suffers from its program-centric structure. Programs required by the permit, such as those that control sediment and runoff from new development, are typically operated in isolation with little or no integration with other related programs (e.g., stream restoration). This often results in program goals having little connection to water quality-based outcomes such as the TMDLs.

Bioretention Cells
Permeable paver parking lot, Baltimore Zoo promotes infiltration of rainfall

Until recently, the MS4 permits in Maryland required permitees to develop watershed restoration plans and implement a program to control sediment and runoff from construction sites. However, there is no requirement to integrate these two programs. Therefore, the impacts from new development are not accounted for in watershed restoration plans, making it almost impossible to achieve a water-quality based outcome. What adds to this problem is that historically, stormwater management programs have failed to mitigate for the effects of development and redevelopment. This failure is because BMPs used to control stormwater were not integrated into the site planning process, which severely limited the kinds of BMPs that can be used and their effectiveness.

Although far from perfect, progress is being made to at least address this latter problem. The State of Maryland recently adopted the Stormwater Management Act of 2007 (SWM 07); SWM 07 requires new and redevelopment projects to use environmental site design to manage stormwater. Environmental site design (ESD) is a revolutionary approach to stormwater management that integrates the management of stormwater via low impact development (LID)[2] techniques into every facet of development and site planning in order to reduce the rate and volume of stormwater discharges. However, while controlling stormwater runoff through integrated site planning represents significant improvements over past approaches, it has become increasingly clear that a more comprehensive approach is needed.

A case in point, SWM 07 has been fervently challenged by some members of the development and planning community as being contrary to smart growth. Their argument is based on a few desktop studies that demonstrate that providing runoff volume control using ESD-LID is too costly and impractical and can result in a loss of density (e.g., buildable lots). As a consequence, green field development becomes a more cost-effective option than redevelopment. Whether these studies have merit or not, the cost of ESD-LID practices, especially on redevelopment sites, can be extremely expensive. It will be almost impossible to justify their widespread implementation, given other priorities in a municipal budget, unless the greater societal benefits of ESD-LID practices are considered.

"Even though it will take years to determine the effectiveness of the WRE in managing our water resources, it is a step in the right direction ... in supporting the national green cities movement"

The key to effective program integration of the MS4 program lies in the broadening of the water quality goals to include more comprehensive societal benefits. Comprehensive watershed planning bridges the gaps between the MS4 permit and local planning by integrating the subset of MS4 permit requirements with a land use and water nexus. The potential of ESD-LID can be maximized when it is integrated into a comprehensive watershed plan. Decisions about where and how to develop within the watershed are evaluated through a planning process that considers, in addition to surface water quality, transportation and water and sewer infrastructure. Once these decisions are made, ESD-LID can then be used to mitigate the impacts from development at a watershed rather than site scale.

The planning process allows for watershed-based offsetting and trading which assures the most cost effective mix of restoration options and addresses many of the issues raised by the development and planning community. This broadens the measurement of success beyond water quality outcomes and integrates water resources, economic and community development goals, and promotes smart growth.

The State of Maryland has made tremendous strides in integrating water resources objectives into the comprehensive planning process. In 2006, the state of Maryland passed House Bill 1141, also known as the Water Resources Element (WRE) that required local jurisdictions to modify their comprehensive plans to assure that existing and future development can be supported by water and wastewater resources (e.g., source water, disposal, infrastructure). The WRE also requires that plans provide goals, policies and strategies for conservation, pollution reduction, and prevention of water quality degradation. Essentially, the plans have to address whether there is enough water and wastewater capacity to support future growth and how much development the watershed(s) can accommodate before the nutrient load threshold (e.g., TMDL) is exceeded. The results must then provide guidance and recommendations in developing the comprehensive land use plan.

Bioretention Cells
Bio-swale for conveying and treating stormwater in San Francisco

Even though it will take years to determine the effectiveness of the WRE in managing our water resources, it is a step in the right direction and could be an essential tool in supporting the national green cities movement so prevalent these days. Baltimore, for instance, has adopted a “Forest Canopy” goal of 40 percent within 30 years. Placing this goal within a watershed planning framework would help round out the economic benefit of this goal by tying it to the full range of societal benefits. For example, the City of Philadelphia developed a master plan to control their combined sewer overflows (CSOs)[3]. Using what is termed as triple bottom line[4] assessment, they estimate that using a combination of traditional and green infrastructure can save them billions of dollars in reducing CSO and meeting their water quality objectives.

Great hope lies ahead in our efforts to meet our water quality goals. We have developed new technology (e.g., green infrastructure), and have identified a comprehensive planning process to effectively implement this technology and consider its value. What must we do to adopt this process globally? The answer lies in part in scientific validation. I made a point earlier that science was regarded as an impediment to implementation and it still is. That is not to say that there haven’t been substantial contributions from science that have led us to this path. However, the state-of-the-art trends in environmental restoration have far outpaced the science to support these approaches. Perhaps the enormity of the task will provide the incentive to allow science to catch up to practice, leading to real progress in managing water resources.


[1] I had the privilege of working with the former JHU Bloomberg School luminary, Dr. Vincent Oliveri
[2] LID practices are commonly referred to as green infrastructure and uses vegetation as a key component in controlling stormwater runoff.
[3] CSOs are discharges of sewage and stormwater into natural waterways which typically occur during storms in cities that have a combined pipe network for sewage and stormwater.
[4] Triple bottom line is a full cost accounting process championed by the sustainability movement that factors in the cumulative social, economic and environment value.


Clean Water Act, TMDL, MS4 Permits, stormwater, low impact development, watershed planning

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The views expressed in this article are those of the author(s) and do not reflect the official policy or position of Johns Hopkins University or the Johns Hopkins University Global Water Program.