Virginia's water supply:
Has shortage replaced abundance?

William E. Cox

Recent droughts plaguing much of the mid-Atlantic and northeastern states have contributed to increasing public concern over the adequacy of Virginia's water supply. A report issued by the Virginia Drought Monitoring Task Force1 in the summer of 1999 identifies several localities that have instituted water-use restrictions in response to potential shortages. Of the problems identified, the City of Roanoke faces one of the most severe situations. Water-level declines at Roanoke's principal storage reservoir have exceeded 24 feet, the triggering level for mandatory water-use restrictions. Controversy over water-supply expansions in the eastern part of the state has also heightened awareness. Virginia Beach has implemented the transfer of water from Lake Gaston after many years of legal and political battles. A reservoir proposal by James City County has been rejected by federal regulators on the basis of unacceptable environmental impacts. The City of Newport News continues to pursue approval of the King William water-supply reservoir but regulatory officials have indicated an intent to deny a critical federal permit.

Do these recent events suggest an end to the traditional water abundance enjoyed by Virginians and a future where water shortage is commonplace? Addressing this question requires consideration of two basic issues: (1) the relationship between Virginia's water resources and water demand and (2) the adequacy of the water management framework.


Naturally occurring water supply has typically been viewed as constant over the long term (the potential for climate change generally has been ignored), while water demand continues to increase over time. Continuing growth in the size of traditional offstream water demands has been accompanied by expansion in the range of demands receiving recognition. These additional demands include instream water-use activities, such as habitat maintenance. Instream demands generally do not consume water, but their satisfaction requires that withdrawal be constrained.

Several factors affect offstream water demand, but a major contributor to growth is an expanding population. Larger numbers of people create greater demand for public water supply and also indirectly generate increased water demand by consuming products and services that require water. Some of the potential growth in demand can be offset by incorporating "demand management" or "conservation" measures but may not be sufficient to prevent all increase.

How much water do Virginians use? The latest water-use data published by the U.S. Geological Survey (USGS) show that Virginians withdrew 5,470,000,000 gallons of water on the typical day in 1995, or 5,470 mgd (million gallons per day).2 Comparing that number to the 27,389 mgd contained in the combined average streamflow of the state's major rivers suggests the absence of a problem. But viewing such totals obscures many aspects of the water-supply issue. Combining total withdrawals is misleading because it ignores water reuse. Most uses do not consume all the water withdrawn, with a significant portion returned after use for subsequent withdrawal and use by others. USGS water-use data for 1995 indicate that only 4 percent of all freshwater withdrawals for offstream use in Virginia was consumed. Combining average streamflow as an indication of total supply is misleading because of variations in water available at different time periods and at different geographical locations. Finally, viewing water withdrawals at a single point in time does not indicate trends and potential for future problems.

Table 1 compares offstream water demand to water supply, both at present and as projected for 2030, for individual river basins and the Eastern Shore area. The demand projections presented come from a 1988 report of the State Water Control Board3 (now included in the Department of Environmental Quality), the most recent state assessment available. Water supplies are shown in Table 1 as the amount of streamflow leaving the state's basins each day. This approach ignores the amount of ground water in storage but includes ground-water contributions to the base flow of streams. Streamflows are given in two forms: (1) average-flows, which indicate the total amount of resource available in the long term, and (2) drought flows, which indicate the amount of water available during relatively rare drought periods. The "1Q30" drought-flow category is determined by statistical analysis of streamflow data and is defined as the flow occurring on the lowest–flow day during each 30–year period. Offstream demand is given as average annual withdrawals for the entire basin or area. The last four columns in Table 1 show demand as a percentage of average flow and drought flow in the 1980-86 period and as projected for 2030.

The columns in Table 1 showing water demand as a percentage of water supply demonstrate that withdrawals are usually not a significant portion of average flows but often exceed 100 percent of flows during drought periods. These percentages during droughts suggest intense competition where some water demands will not be satisfied, but conflict may be mitigated by water reuse. The demand/supply percentages vary significantly among the basins, giving some indication of different water-use intensities. These differing intensities of use perhaps provide insight into the varying potential of the state's river basins for future water-supply problems.

Comparison of average flows to drought flows indicates the significant extent to which natural water supplies vary over time. Public water-supply systems traditionally have selected sources having a flow rate that exceeds maximum system demand even under drought conditions, or such systems have included storage (usually a reservoir) adequate to meet supply deficits during drought periods. Storage provides the primary means by which more of the average flow can be made available for use; construction of reservoirs, however, is one of the most controversial water-management activities. Supply values shown in Table 1 do not account for the water stored in reservoirs that exist throughout the state; withdrawals shown in Table 1 also exclude withdrawals from artificial impoundments.

The use of total streamflow leaving a basin as an indication of water supply can overstate available supply within that basin. Detailed assessment of supply adequacy requires consideration of the distribution of both water and water use within the basin. Water availability is greatest in the lower portions of the basin at sites near the mainstream. Potential supply shortages can occur in a basin with overall adequate supply when water use is concentrated in upper portions of the watershed or at locations away from the mainstream. Another area of supply difficulty illustrated by recent water-development controversies in Virginia is the coastal plain region where major rivers become estuaries that no longer serve as sources of fresh water. Conflicts between water withdrawal and instream demands can occur anywhere within a basin as a result of the proximity of withdrawals to the occurrence of significant instream values. Thus, water-use conflict depends on a variety of locational details and relationships among individual water-using interests. Large-scale assessments based on comparison of withdrawals to total water resources within basins provide only a first approximation of the potential for water problems.


The importance of a properly functioning management system increases with increasing potential for conflict among offstream uses and between offstream and instream uses. Both the public and private sectors make water-supply decisions. Many offstream water supplies are developed by private parties within the constraints imposed by property rights and governmental regulations. Applicable regulations are largely administered by the state and federal levels of government; they primarily focus on environmental protection and human health concerns. Governmental bodies, primarily at the local level, are also involved in the provision of water supply, a situation that creates the potential for intergovernmental conflict as regulators impose constraints on governmental water suppliers.

In Virginia, towns, cities, and counties must plan and develop adequate facilities for withdrawal, treatment, storage, and distribution of water supplies. "Water problems" are often the result of facility limitations rather than true water scarcity. For example, an intake may not operate at lower water levels although adequate water may be available. Although such infrastructure problems can be distinguished from the water-availability issue, they are equally critical to the water user who does not receive water as a result.

The state role in the provision of water supply, in contrast to its regulatory role, is relatively small, consisting of technical and financial assistance to local water suppliers. The state does encourage water suppliers to maintain adequate water sources. Regulations of the Virginia Department of Health,4 which focus primarily on drinking-water quality, require the owner of a regulated waterworks to develop plans for system expansion when water production levels reach 80 percent of capacity for three consecutive months. State government has not been directly involved in the development of water supplies, nor (with a few exceptions) has it played a significant role in the facilitation of conflicts between water suppliers and other localities, other states, and the federal government.

State government has developed mechanisms to protect instream water use from destruction by withdrawals. Basic institutional recognition takes the form of a Virginia statutory declaration that beneficial use of state waters includes both offstream and instream use.5 A mechanism for protection is provided by the Surface Water Management Area Act,6 which establishes a process for implementing a water-use permit program within areas where significant instream values are threatened. Within areas designated under the act, major offstream uses must obtain a permit. These permits are to contain conditions that restrict water withdrawal in certain low-flow situations. The Virginia Water Protection Permit7 provides another mechanism for protection by allowing the imposition of low-flow requirements on applicants for certain federal permits. The Clean Water Act authorizes such state action by requiring state consent before federal permits can be issued for activities involving discharges into navigable waters.8

The protection of natural water environments is also the focus of federal regulatory programs. The Clean Water Act creates one of the most significant means of protection. The act requires federal approval of "discharge of dredged or fill material" into navigable waters,9 a provision applicable to a wide range of activities that modify natural water bodies. Approval requires a permit from the U.S. Army Corps of Engineers that can be vetoed by the U.S. Environmental Protection Agency solely on the basis that the environmental impacts of the proposed activity are unacceptable. Projects that involve destruction of wetlands are especially likely to face denial of the Corps permit or permit veto by EPA. Water-supply reservoirs often fall into this category, especially in eastern Virginia where wetlands are extensive and likely to surround most bodies of water. As indicated by the previously mentioned James City County and Newport News resevoir projects, this permit requirement has become a major factor in water-supply development in Virginia.

The effort to protect natural water environments and instream activities has contributed to a change in the prevailing philosophy guiding water-supply management. The long-standing goal of water suppliers has been to ensure highly dependable supplies with a low probability of shortage. This approach minimizes the need for system managers to impose water-use restrictions or other demand-reduction measures on system customers. As a consequence, it emphasizes supply development as the principal means of maintaining balance between supply and demand.

A shift toward greater reliance on demand reduction as a means of balancing supply and demand has occurred, partly in response to a widespread desire to reduce the environmental impacts of water-supply development. Demand reduction can take many forms, some of which are relatively painless for water users. After the implementation of such measures as water-saving plumbing, however, demand reduction can take more disruptive forms, such as water-use restrictions and financial penalties for specified water-use practices. An especially aggressive form of demand reduction is known as "drought management." In this approach, water systems operate with less supply, which means a higher probability that normal demand will exceed supply in a given time period. A key aspect of drought management is a plan to curtail normal demand during these periods of inadequate supply by activating predetermined water-use restrictions. This approach assumes that the disruptive aspects of water-use restrictions can be mitigated by prior planning.

Movement away from the supply- expansion philosophy toward the more aggressive forms of demand reduction represents a basic shift in management philosophy and the standards of water-supply dependability. By design, supply becomes insufficient to meet normal demands more frequently, and water users will experience more frequent water-use restrictions. Such revisions were likely inevitable in view of past excesses in water-resource use and development, but the shift seems to be well underway without significant public debate. The typical water-system customer will likely not recall any opportunity to express a preference. Federal program administrators have primarily accomplished this shift through implementation of environmental statutes. One of the most significant of these statutes is the Clean Water Act, which provides a basis for prohibiting water supply developement on environmental grounds alone without regard to the overall balance of costs and benefits. Federal influence has been especially significant in the absence of a strong state presence in development of water-supply policy.


Virginia continues to enjoy favorable water-supply conditions. Within a general condition of plentiful supplies, however, localized shortages will occasionally interfere with offstream uses. These problems will occur within limited areas in the future as they have in the past due to incompatibilities between water-supply distribution and distribution of population and economic activities. The most widespread shortages will continue to be associated with severe droughts that approach or exceed the worst recorded low-flow conditions. Shortages will generate proposals for additional water storage or perhaps for water transfer. Proposed transfers may involve relatively short distances but will be controversial, especially if they cross political boundaries.

Conflicts between instream and offstream water uses may be more common than those among offstream users. The impacts of a given withdrawal on instream users may occur prior to any impact on other withdrawals. As long as water is available in the source of supply, offstream users may be able to co-exist while instream uses suffer significant harm. Predicting the location of offstream/instream-use conflicts is hampered by the lack of information about instream demands. The Shenandoah basin provides an example of an area with potential for such conflict. Discussions of applying the Surface Water Management Area Act have been undertaken. Minimum-flow studies are underway to determine instream demands.

In view of this potential for water problems and conflict, flaws in the institutional framework for management need attention. Several changes in governmental programs could reduce the occurrence or severity of water-supply problems. The action with greatest potential to increase performance of the management system is an increase in state activities involving water supply.

A fundamental need is for state government to elevate water-supply planning to a higher status. The commonwealth has undertaken substantial planning efforts in the past and continues to maintain some program elements, but no continuous, systematic effort is currently under way. As evidence of this lack of attention, the last comparisons of water supply to projected demands were reported in 1988. Supply and demand considerations are a basic part of water planning, but planning must also encompass a continuing analysis of policy issues, intergovernmental relations, and interactions among competing water interests. When considered in this light, planning must be a continuous process and not a series of discreet, disconnected actions.

Within the current institutional structure, water-supply planning is part of the mandate of the Department of Environmental Quality,10 which appears to be the most logical location for this function. However, a hazard associated with this location is the tendency for the water-supply focus to be displaced by water-quality planning and management activities, which are often dictated by federal requirements. Water-supply and water-quality planning are complementary, but DEQ's organization structure for planning should provide adequate separation between these two activities to ensure continuing focus on state water-supply issues.

One area needing emphasis within state planning is the assessment of water needs associated with fish habitat and other instream water uses. Instream water use draws wide public interest and requires use of special analytical procedures for the assessment of needs. Intensive studies have been conducted or are under way in limited areas of the state, but information on such needs is generally limited. Effective use of the Surface Water Management Area Act would be enhanced by increased information about the status of instream uses in the state's water bodies. In addition, proponents of water-development projects would be better informed about the prospects for project approval in alternative locations.

Public water supply is a second area of special importance in state water-supply planning due to its close association with the public welfare. While local governments primarily provide public supply, the local geographic perspective is inadequate for broad, long-range resource assessments. The state is in a unique position to conduct such planning from a regional or river-basin basis to support more detailed local studies in connection with individual water-project proposals.

State water-supply planning could also assist providers of public water supply by establishing performance standards for water systems. Guidance is needed in such areas as appropriate level of demand reduction to be implemented prior to development of proposals for increasing available supply. Traditionally, owners of waterworks have enjoyed considerable discretion to make such decisions within the framework of project economic analysis, but these issues are closely scrutinized in today's regulatory procedures. Assumptions used to calculate water deficits can ultimately lead to the denial of necessary approvals. Denials generally are not based on potential inadequacy of the proposed system to meet future needs, but rather on perceptions of excess capacity and unnecessary environmental damage. Project owners currently must navigate the regulatory processes without the benefit of standards or guidance on acceptable choices in project design. A state effort to provide guidance would make a valuable contribution to water-supply management by local governments.

State government should facilitate local water-supply management in a third way by taking a more active role in resolving conflict associated with local water-supply proposals. The most logical water-supply sources for a locality often lie across a local political boundary, with the result that implementation is met with substantial opposition. Although other resources are readily transported across boundaries, water transport often is not acceptable. This lack of acceptability is due to the environmental aspects of transporting water and the fact that water is not usually treated as a marketable commodity for which compensation is paid to the area where the water originates. Beyond these sources of opposition, resistance to water transport becomes philosophical, as water is viewed as an inseparable part of the landscape and a basic part of the sense of place that makes an area unique. Since conflict is inevitable and especially difficult to resolve, state government should facilitate conflict resolution by coordinating meetings and offering services in such areas as information collection and analysis.

State government should also act as a facilitator whenever water-supply conflicts arise between local governments and other states or with the federal government. Virginia Beach's Lake Gaston water-transfer proposal provides an example of attempted state facilitation involving another state. Here, Virginia and North Carolina created joint committees to seek mutually acceptable solutions to the conflict. The effort to resolve the conflict by negotiation ultimately failed, but such efforts are an appropriate state water-management activity. The state has not been a major participant in conflicts between localities and federal agencies over proposed projects such as the Ware Creek reservoir or the King William reservoir. After determining that a given project is consistent with state guidelines and in the best interests of the citizens of the commonwealth as a whole, the state should be an aggressive advocate of the project and intervene on behalf of the locality involved in all relevant decision processes.

Local government should also enhance public water supply by assigning a high priority and conducting continuous planning to ensure that facilities remain adequate. Localities should seek to increase system dependability and performance during droughts by coordinating with other water systems in their areas. System interconnection provides a means to share water to mitigate localized shortages. The merger of independent waterworks into regional systems may be desirable in some situations. Opposition to mergers may exist in some localities due to such concerns as maintaining a low water rate for system customers, maintaining income from current contracts to sell water, or the basic appeal of independence, but the cost of maintaining such benefits may be lower system dependability.

The federal government affects water supply most directly through its regulatory functions (it also provides financial assistance for water systems). Federal regulatory controls have become a major obstacle as local water suppliers attempt to expand water supplies in response to growing populations. A principal problem needing attention is the lack of a broad resource management perspective in such programs as the Clean Water Act's permit for the discharge of dredged or fill material. A program that can disapprove a project proposal on environmental grounds without regard to the availability of alternatives or the overall merits of the project appears unreasonable. Coordination with the water-management programs of the affect-ed state is needed. As noted previously, a concurrent need is a viable state water-supply program and aggressive participation of state government in the federal program. But state participation alone cannot correct a flawed federal approach.

The changes proposed here will allow Virginians to continue to enjoy the many benefits of the state's water resources with a minimum of conflict. Additional water development is inevitable because of population growth and uneven distribution of natural supplies among geographic areas and different time periods. Controversy will continue to surround most proposals, a fact that emphasizes the importance of sound information for decision making and efficient procedures for resolving conflicts. The system must ensure that necessary development is accomplished in an environmentally sensitive manner but should incorporate environmental assessments into holistic appraisals of total project merit. Enhanced planning and management are the key factors to finding the appropriate balance among competing interests to ensure that the water resource makes its maximum contribution to the welfare of the citizens of the commonwealth.

    Author's acknowledgment: This paper is based in part on preliminary results of research being conducted under a grant from the Virginia Water Resources Research Center at Virginia Tech.

    1 Virginia Drought Monitoring Task Force, Drought Status Report, July 9, 1999.
    2 U.S. Geological Survey, Circular 1004, 1988; Circular 1081, 1993; and Circular 1200, 1998.
    3 Virginia Water Control Board, Planning Bulletin 347, 1988.
    4 Virginia State Department of Health, Waterworks Regulations, 1995.
    5 Va. Code Ann. sec. 62.1-10.
    6 Va. Code Ann. sec. 62.1-242 et seq.
    7 Va. Code Ann. sec. 62.1-44.15:5.
    8 33 U.S.C.A. sec. 1341.
    9 33 U.S.C.A. sec. 1344.
    10 Va. Code Ann. sec. 62.1-36 et seq.

Table 1

Comparison of Virginia's water supply and offstream water demand

Basin/Area Supply (mgd) Demand (mgd) D/Avg.Sup.(%) D/1Q30 (%)
Avg. 1Q30 1980-86 2030 1980-86 2030 1980-86 2030
Big Sandy 832 6 7 15 1 2 108 236
Chowan 2195 21 76 91 4 5 398 548
Eastern Shore 40 - 15 30 36 76 - -
James 7964 285 1470 1647 18 21 512 578
New 2617 457 461 462 18 18 100 102
Potomac 2481 159 2674 401 12 16 195 254
Rappahannock 1075 10 23 44 2 4 227 440
Roanoke 3900 217 134 187 3 5 62 86
Shenandoah 1644 151 98 121 6 7 65 80
Tennessee 2605 179 45 61 2 2 25 34
York 2036 27 37 69 2 4 140 272
Total for State 27,389 1512 2674 3128 10 11 170 207

Source: Virginia Water Control Board, Planning Bulletin 347, 1988.

William E. Cox is a professor of civil and environmental engineering at Virginia Tech, where he teaches and conducts research in water resources management. He has served on numerous national and international water-management committees and working groups and has written extensively for state, national, and international journals. His research has focused on the improvement of decision processes associated with the transfer of water, the protection of water from nonpoint source pollution, and the resolution of conflict between water-supply development and protection of natural water environments.