Gestion_par_bassins_versants

Diana Qing Tao, BPR

Watershed management is a holistic approach to water resource and water quality management that is based on the watershed, which is water’s fundamental geographic unit. The terms “catchment” and “basin” are often used as well. Watershed management examines issues based on all water uses, inputs and withdrawals in the watershed and develops management plans and solutions to problems in an integrated fashion. It focuses as much on the uses of land as it does the inputs and withdrawals of water.

Watershed management is a centuries-old concept that has more recently developed into a new approach and terminology which focuses on quality and land use issues. Today, watershed management has technical, political and managerial implications.

- From a technical perspective, watershed management requires examination of all water uses and land uses that might impact water, all in the context of the watershed geographic unit. It also implies a rigorous scientific assessment that quantitatively links causes, actions and effects.
- From a political perspective watershed management implies wide stakeholder involvement in the entire process from goal setting, to scientific studies, to alternative evaluations, to final planning and prioritization.
- Last, from a managerial perspective, watershed management includes a range of solutions and management actions, not only control of pollutant discharges and water withdrawals but also changes in land uses and physical features in terms of and how they impact quality, quantity and uses in the water body.

Watershed management efforts globally have been quite varied and are at different levels of evolution and different focus. In Asia and Australia, watershed management is rooted mostly in managing water availability but quality issues are quickly growing. In Europe, both availability and quality have been a long concern but a focus on land sources is now evolving. In developing countries like Africa, watershed management is very resource limited and generally only focuses on small sub-watersheds. Central and Latin American countries also have resource limitations, but have found innovative ways to improve watersheds by paying for environmental services. In the United States, watershed management is the standard paradigm for water quality management but the effectiveness of these programs is mixed.

This presentation will explore the fundamentals of watershed management for stakeholder involvement and goal setting, to problem assessment and finally watershed management plans. The presentation will highlight and compare examples of how watershed management has been applied in various areas around the globe.

Paul Freedman, LimnoTech

The Clean Water Act (CWA) section 301(a) prohibits the discharge of any pollutant from a point source into waters of the United States except in compliance with certain enumerated provisions of the CWA, among them section 402. CWA section 402 establishes the National Pollutant Discharge Elimination System (NPDES) program, under which The Environmental protection Agency (EPA) or states and tribes authorized to administer the program issue permits that allow the discharge of pollutants into waters of the United States.

Since 1994, the EPA has recognized the critical importance of integrating the precepts of watershed management into the NPDES permitting process. With the released of the first-ever NPDES Watershed Strategy, EPA presented a framework for addressing point source permitting issues within the context of limited resources and diffuse environmental impacts and priorities. This concept has become known as “Watershed-based NPDES permitting”. This approach to developing NPDES permits for multiple point sources within a defined geographic area (watershed boundaries) is different from the current approach to permitting because it considers watershed goals and the impact of multiple pollutant sources and stressors, including nonpoint source contributions.

Watershed-based permitting may encompass a variety of activities ranging from synchronizing permits within a basin to developing water quality-based effluent limits using a multiple-discharger modeling analysis. The types of permitting activities will vary from watershed to watershed, depending on the unique circumstances in the watershed and the sources affecting watershed conditions. The ultimate goal of watershed-based NPDES permitting, however, is to develop and issue NPDES permits that consider the conditions of the entire watershed and address the diverse sources within the watershed, not just an individual point source discharger.

This presentation will discuss the basic concepts of a watershed permitting analytical approach, explain what resources are available to stakeholders, and touch on a few real world case studies where watershed-based permitting has been successful in the United States.

Danielle Stephan, US EPA

Water and Energy are emerging as the two critical resources facing humanity. Water shortages are already present in various urban and agricultural watersheds in Canada and the USA and increased climatic variability will accelerate these emerging problems. At the same time non-point sources of water pollution from urban, agricultural and forested land uses are providing new challenges for drinking and wastewater treatment operations. New approaches are needed to control demand and share scarce water resources between human and environmental use. Source water protection has now been given serious considerations and innovative approaches to stormwater management are being introduced into new urban development. The shift is from directing stormwater runoff into local stream to detaining and infiltrating water into soils wherever possible. Introducing beneficial management practices in all land use activities will help protect water supplies and water quality. A shift needs to be made between blue and green water management and serious considerations need to be given to measuring the water footprints for every land use, domestic and industrial activity.

Climate change and land use intensification both occur at the same time and the combined impact on water resources is difficult to isolate. However, there is clear evidence that climate change is increasing the variability and intensity of storms, and land use change is altering the runoff, evaporation and infiltration component of the hydrological cycle. In different parts of North America this will result in earlier snowmelt and longer dry periods. Such a shift will require significant changes to the way we store and manage water resources. We also have to deal with many new emerging contaminants and higher pollution loadings in rivers.

Individuals in North America are the largest water consumers and introducing efficient demand management practices can go a long way in reducing water scarcity. More careful management of nutrients and other chemicals is also readily possible. If we make a concerted effort to adopt innovative approaches to all these problems we can significantly reduce the risk of water scarcity and water contamination and many of the effective actions will be highlighted in the presentation.

Hans Schreier, University of British Columbia

Diana Qing Tao, BPR

In light of the many global environmental challenges our world faces, now is the time to apply the tools, methods and philosophies that can make a positive difference for the future of our planet. Since Ian McHarg’s development of the weighted overlay modeling technique in his 1969 seminal text, Design with Nature, significant strides in computer technology have made the technique powerful and widely applicable to the fields of planning, design, science, and engineering. McHarg’s message of thoughtful planning and design that integrates natural systems with the built environment remains pertinent, yet many times unobserved. When integrated into the design and planning process, purposefully applied GIS modeling can extract an understanding of the structure and function of natural systems, which can help guide future decision making and restore the balance of environmental health with the human need for development and resource utilization.

This session will present an overview of a flexible GIS modeling process that has been developed and applied for a variety of projects in the Mid-West United States, ranging from area plans, stormwater green infrastructure planning, roadway alignment alternatives, and parks and greenway planning. The author will present several case studies of the applied GIS modeling process. The case studies include the development of a stormwater green infrastructure locator for Kansas City, Missouri and Omaha, Nebraska, a county-wide Environmental Sensitivity Index (ESI) aimed at helping align a future roadway and develop a parks master plan, and integration of the ESI, green infrastructure locator, and population projection modeling to develop sustainable benchmarks for an area plan within Kansas City, Missouri. The case studies will present both planning scale results from the GIS modeling and site scale design responses derived from the modeling results.

Bryce Lawrence, Patti Banks Associates

Urban watershed planning and management involves a wide range of activities that together are designed to protect public health and ecological systems. A critical aspect of urban watershed planning is to understand how a watershed will react under a variety of environmental conditions. To do so computer modelling tools have been mainstays of the water industry assisting professionals make informed decisions based on a sound technical and scientific basis. The range of models and the application of modelling tools in urban watershed vary greatly, geographically, by agency as well as by professional preference. However, the foundation of these modelling tools, whether for quantity or quality, surface or sub-surface are based on the same fundamentals. The most important question in using models is to understand the modelling objective(s) and selecting the right tool to meet these objectives. This presentation explores these questions through the selection and application process. It also looks at how new technology such as geographical information system and new low impact development approaches are becoming integral to urban watershed planning and management.

Philip Gray, XCG Consultants

Jerry Jones, Malcolm Pirnie

Louise Babineau, Ville de Québec

Paul Freedman, LimnoTech

Christopher S. Crockett, Philadelphia Water Department

The metropolitan Atlanta area has grown substantially over the last 20 years and continues to be one of the faster growing urban areas in the country. This growth has resulted in land use changes that have accelerated stormwater problems including localized flooding and water quality and habitat degradation. In 1996, Georgia and Region IV of the US Environmental Protection Agency (EPA) lost a legal challenge regarding Total Maximum Daily Load (TMDL) development and implementation; primarily related to the continued degradation of water quality for stormwater and associated non point source pollutant loadings. As a result, Georgia was required to meet an accelerated schedule for TDML implementation.

Faced with the challenges of TMDL implementation demands and concerns for the future assimilative capacity of metro area streams, and water supply water quality and availability, Georgia created the Metropolitan North Georgia Water Planning District (District) to address the need for comprehensive stormwater and watershed management in the rapidly developing North Georgia area. A total of 16 counties in the metropolitan Atlanta area were included in the District encompassing over 6,700 square miles. There are six major river basins within the District including the Coosa/Etowah, Chattahoochee, Oconee, Ocumulgee, Flint, and Tallapoosa river basins. Specifically the watershed management plan provided recommendations for programmatic measures that should be applied across the entire District as well as watershed specific measures to address existing or anticipated watershed conditions. In addition, the watershed management plan was coordinated with the water supply and wastewater management plans that were developed concurrently.

Development of the comprehensive watershed management plan focused on leveraging existing programs, where appropriate, and identification of additional management measures required to maintain or improve water quality and aquatic habitat conditions. The overall goal was to develop a long-term program that met multiple objectives including meeting water quality standards, TMDL implementation, source water protection, and reduction in downstream flooding. To meet these goals, a change in overall philosophy was required from the traditional stormwater end of the pipe engineering approach to one that eliminates the causes by proactively preventing stormwater problems before they occur. Greater emphasis on site planning and design to better mimic the natural hydrologic regime will be needed to reduce downstream hydrologic impacts and associated non-point source pollutant loads. In addition, significant watershed restoration activities will be needed in the already developed areas to improve stream conditions to meet designed uses. This watershed management program has been in place for 5 years and despite the comprehensive strategy, the program has had only limited success due to inconsistencies in implementation of local watershed management programs.

Doug Baughman, CH2M Hill

The Boothbay Region Water District is a quasi-municipal water district serving the towns of Boothbay, Boothbay Harbor, and Southport in a peninsular area of mid-coast Maine, a region heavily dependent on tourism and subject to seasonal shifts in population density. The District’s principal water source is Adams Pond; Knickerbocker Lake is its backup supply. The watersheds of both sources are relatively small, 1.50 and 1.59 square miles respectively, and are highly prized resources. Both water bodies are located in Boothbay, but most of the District’s customers live in Boothbay Harbor. This disparity created political friction until the present district was created by consolidating the water districts that had served the two towns.

The Boothbay Region Water District operates a state-of-the-art water treatment plant that treats 2 million gallons per day. Recognizing the importance of the multiple barrier approach, the District first seeks the highest quality raw water and, in the process, reduces treatment costs. In light of rising petroleum prices, chemicals for treatment are becoming more expensive. Plant efficiency is noticeably improved with cleaner source water due to the reduced need for electricity and water treatment.

The Maine Department of Health’s Drinking Water Program completed a Source Water Assessment Program (SWAP) review and determined Adams Pond was the most threatened water supply in Maine. Armed with the SWAP report, the District cooperated with various governmental agencies to address gross non-point source pollution problems. In addition, phosphorous levels in the two water sources necessitated passage of a watershed protection ordinance subject to a town-wide vote. To aid in enforcement of both phosphorous levels and non-point source pollution problems, the District funds, through Boothbay, a dedicated code enforcement officer to educate the public and enforce proper erosion control measures under state and local regulations. The defining moment in watershed protection came during the consolidation of the East Boothbay Water District and the Boothbay Harbor Water System into the present Boothbay Region Water District. Overnight, local Selectmen and Boothbay voters chose to “buy in” to the Boothbay Region Water District, and embrace common goals for the watershed.

The regulatory effort is supplemented by public education through local environmental groups and schools, which increases awareness and support for protecting the water supply. The Knickerbocker Lake Association, composed of owners of lake front property, promotes lake protection and public awareness of sound stewardship practices.

The district has developed tools including land acquisition and forest land protection through a myriad of land acquisition and protection strategies and by forging alliances with the Boothbay Region Land Trust and other philanthropic organizations. In addition the district has initiated best management practices to protect water quality through various partnerships.

The District believes the primary factor for its success thus far is political. The community’s political will enabled watershed protection action. Originally, the District tried unsuccessfully to take a more aggressive approach with Boothbay. Education and voluntary acceptance, or “buy-in,” turned out to be more successful. The survey and SWAP were key factors in informing the public and creating political support. Now, it is “politically correct” to support water quality protection. Still, regulating land use will continue to be a political challenge.

Throughout this process of adopting a watershed-based approach to management, the Boothbay Region Water District has learned the importance of developing a source water protection plan to guide management, devoting staff to plan implementation, staying alert to local opportunities to enhance source protection, building partnerships, leveraging federal and state regulations for local purposes, and educating local citizens and officials.

Jon Ziegra, Boothbay Region Water District

Louise Babineau, Ville de Québec

Paul Freedman, LimnoTech

Tad Slawecki, LimnoTech

Christopher S. Crockett, Philadelphia Water Department

How can water management become more sustainable through the planning and design of urban development projects? Several recent projects highlight the potential to manage stormwater with a very high degree of water quality treatment, beneficial reuse, energy savings, and even flood protection as a result. The best solutions go beyond mere compliance with stormwater regulations, and enter the realm of embracing environmental sustainability on the site scale. Low impact development techniques often include raingardens and biofiltration swales, as well as more mechanized systems for water harvesting, all falling into the category of green infrastructure for water management. Often the true benefits result from synergies between elements. For example, above and beyond the eye appeal and runoff reduction of vegetated roof top technologies, detailed analysis consistently demonstrates that green roofs are a smart choice to save money while delivering improved water quality, air quality, energy savings, and public enjoyment. Ms. Goldsmith will explore the topic of green infrastructure case studies outlining features, benefits, and anecdotes affecting decision-making; computational models for stormwater management functions and life-cycle cost/benefit analysis of green infrastructure; and issues affecting regulatory acceptance including tailored ordinances and incentives.

Wendi Goldsmith, Bioengineering Group