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Watershed Research for Water Management

Watershed research in the U.S. Geological Survey (USGS) is guided not only by the need to expand basic knowledge of watershed processes but also by the needs of other public and private organizations for a better scientific basis for design and implementation of management programs. Among public agencies that depend on the USGS and other endeavors in watershed research are management programs at the federal level, including the Natural Resources Conservation Service (NRCS), Army Corps of Engineers (COE), Bureau of Reclamation (BuRec), Forest Service, Environmental Protection Agency (EPA), Fish and Wildlife Service, and National Weather Service. At the state level are water quality management and other natural resources agencies. Local governments are particularly active in management of watersheds that serve as public water supplies and in management of stormwater from urban watersheds. Many private-sector endeavors also are dependent upon knowledge gained from watershed research, including privately owned water supply and electric power utilities, forest products companies, and other manufacturing industries. The information needs of those users are many, and an appreciation for the nature of watershed activities undertaken by those organizations is important to USGS as it pursues its research endeavors.

WATERSHEDS IN RESOURCE MANAGEMENT

Origins

Use of watersheds or river basins as the fundamental spatial unit for analysis is one of the earliest principles to evolve from American policies for planning and managing water resources. Its roots reach to the middle of the



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Watershed Research in the U.S. Geological Survey 2 Watershed Research for Water Management Watershed research in the U.S. Geological Survey (USGS) is guided not only by the need to expand basic knowledge of watershed processes but also by the needs of other public and private organizations for a better scientific basis for design and implementation of management programs. Among public agencies that depend on the USGS and other endeavors in watershed research are management programs at the federal level, including the Natural Resources Conservation Service (NRCS), Army Corps of Engineers (COE), Bureau of Reclamation (BuRec), Forest Service, Environmental Protection Agency (EPA), Fish and Wildlife Service, and National Weather Service. At the state level are water quality management and other natural resources agencies. Local governments are particularly active in management of watersheds that serve as public water supplies and in management of stormwater from urban watersheds. Many private-sector endeavors also are dependent upon knowledge gained from watershed research, including privately owned water supply and electric power utilities, forest products companies, and other manufacturing industries. The information needs of those users are many, and an appreciation for the nature of watershed activities undertaken by those organizations is important to USGS as it pursues its research endeavors. WATERSHEDS IN RESOURCE MANAGEMENT Origins Use of watersheds or river basins as the fundamental spatial unit for analysis is one of the earliest principles to evolve from American policies for planning and managing water resources. Its roots reach to the middle of the

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Watershed Research in the U.S. Geological Survey nineteenth century when debate began on alternative strategies for managing floods along the Mississippi River, whether the policy should be one of building levees alone in the vicinity of properties exposed to risk or one of levees in combination with reservoirs in headwater streams. It was also at the core of much of the nation's early earth science research, as characterized particularly by the Colorado expeditions of John Wesley Powell, second director of the U.S. Geological Survey. The concept of watershed management was elevated during the conservation movement in the early twentieth century through the work of several commissions during the presidency of Theodore Roosevelt. W.J. McGee, one of several influential leaders in the administration, wrote in an article in 1907 that each stream is an interrelated system in which control of any part will affect, to some extent, every other part. Watersheds became a cornerstone of planning practice beginning in the 1920s as federal agencies, including COE, BuRec, Tennessee Valley Authority, and the Soil Conservation Service (SCS) began planning for development of the nation's waterways. That concept was central to much of the public and private development to improve navigation, control flooding, and develop rivers for hydroelectric power, water supplies, and recreation, activities that reached a peak in the mid-1960s. For much of that period the emphasis in watershed research was on enhancing knowledge about quantities of water and its movement in streams, floodways, and reservoirs. Some problems addressed by those planning activities remain national priorities today. Paramount among them is flood damage. Devastating floods in the Upper Mississippi Basin in 1993 were directly responsible for the loss of 38 lives and fiscal damage estimated to be in the range of $12 billion to $16 billion (Administration Floodplain Management Task Force, 1994). In the 1980s, average annual flood damages were approximately $4 billion in 1985 dollars (Federal Interagency Floodplain Management Task Force, 1992). Erosion and Sedimentation Perhaps the largest national program of watershed management is overseen by the NRCS. Concerns about erosion and sedimentation reached the status of a national priority in the early 1930s, leading to establishment of the SCS in 1933. Among its first initiatives was a set of demonstration projects that proved soil conservation and water conservation were inextricably linked. For the first 20 years of that program, conservation measures were limited to land treatment and minor structures for land stabilization. By the

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Watershed Research in the U.S. Geological Survey Agriculture development of forested lands has dramatically increased sediment yields in basins such as the Cayaguás in Puerto Rico. In this case, the sediment has been deposited in the principal water supply reservoir for the city of San Juan, Puerto Rico, causing a 60 percent reduction in its storage capacity since impoundment in 1954. Source: U.S. Geological Survey. late 1940s, however, a substantial lobby had developed for structural measures in upland areas, and that pressure culminated in the passage of the Watershed Protection and Flood Prevention Act of 1954, also known as P.L. 566. This law provided 100 percent federal funding for flood control structures and 50 percent federal funding for other project purposes, including wildlife and recreation. With those incentives, SCS broadened its agenda, becoming a significant force in a wide variety of project purposes. Since 1954, the SCS (now called the Natural Resources Conservation Service) has initiated nearly 1,600 watershed projects, among which over 300 that started since 1975 are still active. Watersheds on which those projects are located have an average drainage area of about 360 square kilometers. The purposes served by these projects have changed significantly since

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Watershed Research in the U.S. Geological Survey passage of the Water Resources Development Act of 1986. Changes in cost-sharing formulas in that act shifted a much greater burden of the financing to local sponsors, bringing about substantial reductions in the percentage of projects used for flood control and drainage, for recreation, and for municipal and industrial water supplies (Figure 2.1 ). Since 1986, a significantly higher percentage of projects have been used for watershed protection purposes that include erosion control and water quality improvements. Changes in that direction are consistent with NRCS's intent of moving toward "ecosystem-based integrated resource planning and management." Strategic plans for the NRCS include a Water Management Action Plan that envisions the agency providing assistance for integrated resource planning and management on a watershed basis (SCS, 1993, 1994). Water Pollution Control Watersheds also were adopted as basic units for managing environmental aspects of water resources, particularly the control of water pollution. A number of states adopted watershed programs for pollution control in the 1930s and 1940s. Federal-state cooperative efforts in the Scioto and Illinois rivers resulted in one of the first water pollution control surveys for an entire watershed. A study authorized by Congress in 1938 of the Ohio River and published as House Document No. 266 in 1944 became a landmark for pollution aspects of watershed management. By 1951, states and the U.S. Public Health Service had prepared initial reports for all major watersheds in the country (Dworsky, 1971). When federal policy emerged in the 1950s and 1960s, the use of watersheds in developing management programs became even more widespread. Experience from some of the better state programs was incorporated into guidance by the Federal Water Pollution Control Administration, encouraging states to use watersheds and river basins as spatial units for development of implementation plans required by amendments to the Federal Water Pollution Control Act in 1965. With these developments, research needs were expanded to focus added attention on the fate and transport of pollutants in streams. Amendments to the Federal Water Pollution Control Act in 1972 brought about a number of fundamental changes in pollution policy in the United States, several of which were dependent heavily on watershed management. Section 303(e) of the act required each state to prepare plans to achieve water quality standards for each watershed in the state, taking into account nonpoint sources of pollution from urban, agricultural, silvicultural, and mining activities as well as point sources of municipal and industrial

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Watershed Research in the U.S. Geological Survey FIGURE 2.1  NRCS watershed projects by  purposes: 1976–1985 and after 1985. Source: NRCS (1996). pollution. Inclusion of nonpoint sources, widely distributed over the landscape and transported by stormwater runoff, increased the importance of watershed processes in pollution control strategies. Section 208 of the act established areawide planning to embrace all municipal, industrial, and nonpoint sources of pollution in watersheds, particularly in metropolitan areas and other regions where point source controls alone were insufficient to satisfy water quality standards. Slow progress toward control of nonpoint sources led to inclusion of Section 319 in reauthorization of the Clean Water Act in 1987. That program established grants to states for reducing nonpoint source pollution on a watershed basis. Although it was initiated prior to 1987, the Chesapeake Bay Program, described in Box 2.1, provides a good example of efforts to manage a complex watershed in which both point and

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Watershed Research in the U.S. Geological Survey BOX 2.1 Chesapeake Bay Program Chesapeake Bay is the largest estuary in the eastern United States with a drainage area of over 165,000 square kilometers, including portions of six states and the District of Columbia. Its highly productive ecosystem provides a rich abundance of fish and shellfish. Its vast area of open waters and surrounding wetlands and forests constitutes an enormous habitat for waterfowl and wildlife. Those same areas constitute a huge recreational resource. But the quality of these resources has been severely damaged from the cumulative effects of population growth (nearly 15 million in 1990), urbanization, industrialization, and intensive agricultural production within watersheds that drain to the bay. Watersheds of the Susquehanna, Potomac, and James rivers, ranging from 650 to 725 kilometers in length, have become highly developed, with over 40 percent of all lands in urban, suburban, or agricultural uses. Land has been developed at much greater intensity near the bay. The bay is now the object of a major cleanup and restoration program involving all levels of government with widespread public participation. Among the highest-priority problems to be addressed are nutrient enrichment, loss of submerged aquatic vegetation (SAV), and toxics. Nutrient enrichment, particularly excessive nitrogen loads, have led to high levels of algal mass and indirectly to low levels of dissolved oxygen. SAV is an important component of the ecosystem, providing food and shelter for fish, finfish, waterfowl, and other aquatic resources. It also serves to filter and trap sediments and nutrients. Stresses imposed by toxics and losses of suitable habitat have led to suboptimal densities of zooplankton and degraded benthic conditions, leading to serious losses of fisheries of commercial and recreational importance. Particularly hard hit have been stocks of striped bass, shad, and oysters. Efforts to formulate management plans for the bay have been under way for over 30 years. In 1965 the COE was directed to examine a broad array of water resource issues regarding the bay. With passage of Public Law 94-116 in 1975, a more intensive five-year, $27 million examination of water quality problems and their solution was initiated by the EPA. That program became known as the Chesapeake Bay Program (CBP). After 20 years of effort, the CBP has

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Watershed Research in the U.S. Geological Survey forged a working partnership with the states, and that partnership has formulated a series of tributary management strategies to address nitrogen and toxic loads. Key elements in those strategies are use of the best management practices for agriculture and urban stormwater runoff and reductions in loads from municipal and industrial sources. information is needed from the research community on processes such as deposition, resuspension, transport, and fate of substances from a wide range of land types and uses. Urban Stormwater Among the earliest nuisances of urbanization that confronted local governments were problems of flooding, traffic disruption, and other adverse effects of excessive runoff from storm events. Many communities responded by developing watershed-wide stormwater management plans. In the 1960s, it became evident that urban stormwater also was having adverse effects on water quality in receiving streams, a special problem being that of combined sewer overflows. Since then, federal policymakers have struggled to find appropriate strategies for reducing those impacts. Until 1987, actions called for in the Clean Water Act were ignored because of the large costs to manage these sources. Amendments in 1987 established a timetable for large urban areas and industrial sites to obtain permits and adopt applicable standards for stormwater discharges. More progressive communities have sought to integrate stormwater management in more comprehensive treatment of urban streams and related floodways. One such effort is that undertaken by the Denver metropolitan area, highlighted in Box 2.2. Among the scientific uncertainties confronted by these initiatives are (1) the transport and fate of nutrients, toxics, and sediments in the urban environment; (2) changes in low flows resulting from modifications to the watershed; and (3) responses of fish and aquatic ecosystems to changes in pollutant loads and habitat conditions, including vegetative cover and substrate.

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Watershed Research in the U.S. Geological Survey BOX 2.2 South Platte River Initiatives Watersheds of the South Platte River in general and more specifically those in the Denver metropolitan area are the focus of several intensive investigations and planning efforts. The river, with its headwaters at the Continental Divide, winds it way along a 725-kilometer route to its confluence with the North Platte River in Nebraska, draining an area of 63,000 square kilometers in parts of three states, home to 2.4 million people. Denver draws its water supply from watersheds of the Upper South Platte; the river and its tributaries are significant urban amenities; those streams carry the runoff from periodic storm events; and the river receives effluent from the Metro Wastewater Reclamation District. The impacts of those uses are apparent in the upper and middle reaches of the river. Downstream reaches are more heavily influenced by agricultural runoff. Twenty years ago the river, as it flowed through Denver, was described as a miserable, flood-ridden sewerway filled with the rubble of construction projects, discarded tires, other solid waste, and waste oil. That was before its potential as a valuable asset to the urban area was recognized. Progress had been made by the early 1990s to establish a green-way system along the river, but more was needed to transform the river and related lands to resources that could be used for a variety of recreational purposes. One initiative taken by local officials, called Imperative 2000, created a vision for the South Platte that would further enhance the river and its corridor as a meeting place for people, as a place for plants and animals to flourish, and as a learning center. Efforts are under way to achieve those goals while continuing to use the river as a public water supply and a conveyance for flood waters. Proposed actions include alteration of magnitudes and timing of flows to meet instream needs, development of a coordinated approach to water quality management, enhancement of natural features of the corridors for recreational and ecological purposes, multiple-purpose utilization of upstream lands for flood reduction and open space, and provision of native species of trees and shrubs to improve vegetative cover for fish and wildlife. Other initiatives are also under way. The U.S. Forest Service is considering designation of portions of the river above Denver as either

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Watershed Research in the U.S. Geological Survey a wild and scenic river or an alternative that would protect the river without formal designation. The state of Colorado, working with the EPA and local governments, is taking steps to formulate waste load allocations and total maximum daily loads for the river. The USGS, has been a significant partner in the array of public and private organizations actively involved in understanding the science of the river. In 1991 the USGS undertook water quality investigations in the South Platte as part of the NAWQA program. Through that effort and a larger effort for the entire Platte River watershed, the USGS is investigating a variety of water quality problems, particularly those related to suspended sediment, pesticides, nutrients, and stream ecology. Public Water Supplies Many local governments also have relied on watershed management to protect their public water supplies. A study of threats posed by urban development to those watersheds and steps taken by local governments to protect them was undertaken by Burby et al. (1983), and a more recent survey of selected local government management programs was published by the American Water Works Association Research Foundation (Robbins et al., 1991). Added attention was drawn to water supply watersheds when EPA adopted its Surface Water Treatment Rule in June 1989, using its authority under amendments to the Safe Drinking Water Act of 1986. That rule, which developed over several years after much public debate, places a number of restrictions on systems that do not use filtration to treat waters taken from surface sources, including several large systems such as those serving New York, Boston, and Seattle. In addition to many other requirements, systems not using filtration must manage their watersheds to minimize the potential for contamination by specific biological organisms. They must monitor and control activities in watersheds that could be sources of specified organisms, and they must demonstrate the capability to control human activities that could adversely affect water quality.

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Watershed Research in the U.S. Geological Survey Watersheds as a Planning Framework In addition to the role of watersheds in particular management contexts, watersheds have become a popular organizing framework for water resource planning in the 1990s. Policy advocates such as Water Quality 2000, a coalition of more than 80 organizations representing a variety of interest groups, have recommended that reauthorization of the Clean Water Act should reorient water resource programs and institutions along watershed boundaries. The Association of Metropolitan Sewerage Agencies has argued for a national program of comprehensive watershed management. In 1991 the EPA developed a ''watershed protection approach'' for its water quality management programs. A recent book, Entering the Watershed, (Doppelt et at., 1993) makes strong arguments for a comprehensive ecosystem-based watershed protection program. EPA's (1991a) framework document for its watershed protection program sets forth the following goals: (1) to encourage state and local governments to target watersheds based on overall human health and ecological risk; (2) to develop site-specific integrated approaches to manage pollution; (3) to establish cooperative decisionmaking processes; and (4) to establish mechanisms for monitoring and evaluation. In March 1994, EPA formulated a statement that management of the resource should be adapted to the needs of particular locations. Subsequently, the agency established a Watershed Management Policy Committee to foster a watershed approach to environmental protection. To implement this program, EPA identified a number of case studies through which methods would be developed. The initial list included 34 projects, ranging in size from a 50-square-kilometer watershed and bay on Cape Cod to a regional project in the Lower Mississippi Valley that covers 219 counties in portions of seven states. Among the most common of problems and threats identified in those watersheds were excessive nutrients and agricultural operations. Sedimentation was cited frequently, as were past mining activities. The Chesapeake Bay, Great Lakes, and National Estuary programs are other instances where watershed approaches have been taken to restore significant large-scale ecosystems. Considerable attention has been fixed on the problem of identifying sources and predicting the transport and fate of excessive nutrient loads in tributary watersheds, including atmospheric nitrogen deposition. Potential leakage from hazardous waste facilities within these basins also has been estimated, and potential sources and fates of bioaccumulative pesticides have been identified. In addition to its support for the case studies, EPA is tracking how states

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Watershed Research in the U.S. Geological Survey are adapting their water quality management programs to the Watershed Protection Approach. Specific components being tracked are (EPA, 1994): the wastewater discharge permit program, monitoring and assessment of water quality, management of nonpoint sources, ground water management, and establishment of total maximum daily loads and waste load allocation. One of the programs that has been highlighted by EPA (1991b) is a "whole-basin" approach devised by North Carolina's Division of Environmental Management. Key elements of this program are to coordinate basin-wide water quality planning with issuance of discharge permits and to integrate management of point and nonpoint sources. Plans for the state's 17 river basins are scheduled to be updated on a staggered five-year cycle, and all discharge permits within each basin are to be reissued when plans are revised. IMPLICATIONS FOR RESEARCH Several elements of watershed management have emerged as being especially important and difficult as priorities have been established on nonpoint sources, pathogenic organisms, hazardous substances, wetlands protection, and ecosystem restoration. Many of those difficulties arise as planners try to apply information obtained at the small scale to formulate and evaluate programs for large-scale watersheds. Much of what is known about watershed management has been gained from work at small scales, and management programs are likely to be implemented at small scales—at the level of farms or even fields, subdivisions, commercial developments, and management of other types of activities. Among the difficult problems is predicting how large-scale ecosystems respond to many small-scale management practices, some of which may be rather distant from locations at which responses will be measured. Because interactions between sources of problems and responses may occur over long distances, an understanding of the transport and fate of chemicals and their impacts on biological organisms is essential to the development of sound management policies. Some pathways through which those materials travel involve interactions between surface water and ground water and between the surface and the atmosphere. Incorporation of ecological systems into watershed management brings its own special set of challenges. While strategies call for integrated, holistic,

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Watershed Research in the U.S. Geological Survey ecosystem-based management, achieving that goal is far more difficult. Responses of ecosystems to management practices have been notoriously difficult to predict at the level of certainty often demanded in policymaking processes, many of which are being directed at causes rooted in land use and land management practices. Improvements in knowledge about watershed processes should lead to better-informed policies regarding land management.