Rappahannock River Basin Commission Water Supply Planning Project
The Rappahannock River Basin is located in eastern Virginia (Figure 1). The Rappahannock River begins as streams flowing from the eastern slopes of the Blue Ridge Mountains, flows southeast through the fall line at Fredericksburg (where freshwater and tidal effects meet), and ends as a wide estuarine river that meets the Chesapeake Bay (Rappahannock River Basin Atlas and GIS Database). The Rappahannock River is 184 miles long and is joined by the Rapidan River at a confluence approximately ten miles northwest of Fredericksburg (Figure 2). The Rappahannock River basin is 2,725 square miles in area, with a maximum width of fifty miles in the headwaters, and a minimum width of ten miles just north of Fredericksburg (Soil and Water Conservation Tributary Strategy) (Figure 1.1). There is also an additional 2,432 miles of streams and rivers within the basin providing an abundance of water resources (Soil and Water Conservation Tributary Strategy).
Figure 1: The Geographic Location of the Rappahannock River Basin in Virginia
Figure 2: The Rappahannock and Rapidan Rivers
For discussion purposes the Rappahannock River Basin can be divided into three geographic sections. The upper basin, where the river and tributaries are made up of freshwater, includes portions of the rural counties of Fauquier, Culpeper, Orange, Madison, Rappahannock and Greene. The middle basin, around the fall line, represents Fredericksburg and portions of the rapidly urbanizing surrounding counties of Stafford and Spotsylvania. The lower basin is the area southeast of Fredericksburg, where the river and tributaries are tidal brackish water. The lower basin includes portions of the counties of King George, Lancaster, Westmoreland, Caroline, Essex, Middlesex, Northumberland and Richmond (Figure 3).
Figure 3: The Upper, Middle and Lower Sections of the Rappahannock River Basin
The rivers provide for wide array of uses within the basin. Uses of the river include commercial fish and shellfish industries, recreational fishing, and water withdrawals for residential, commercial, industrial and agricultural uses. In addition, the river provides for recreation activities such as boat tours, camping and rafting and it is the basis for a small tourism industry based on the river. In addition, conservation areas, such as a 4,842 acre National Wildlife Refuge in the lower basin and two Nature Conservancy Preserves, provide natural habitat areas that foster bird watching and conservation education opportunities (Wildernet).
The abundant and diverse fish in the river constitutes an important resource in the basin. Fisheries in the river vary substantially between the two zones of the river: northwest of the fall line at Fredericksburg and southeast of the fall line. Northwest of the fall line, the river is usually clear, swift and dominated by bedrock, boulder and cobble substrates. This provides habitat for smallmouth bass and other freshwater species. Southeast of the fall line, the river is tidal resulting in a finer sandy substrate and frequently murky water. The river below Fredericksburg is home to alewife, largemouth bass, channel and blue catfish, and white and yellow perch (Virginia Department of Game and Inland Fisheries). The river also hosts anadromous fish that live in the oceans but return to freshwater areas to spawn. The American shad, blueback herring and striped bass are anadromous species that have historically used the river as spawning and nursery habitat.
In 2003, the only dam along the main stem of the Rappahannock River, Embry Dam,was removed. The dam, built in 1910, was located on the Rappahannock River 2.4 miles upstream from the center of Fredericksburg. The dam’s removal facilitated an increase in population of American shad and other anadromous fish species by providing access to historic spawning grounds. The removal of the dam and the increase in population of American shad, in particular, is important because of the historic significance of the shad fishery in the region. American shad harvests in the Chesapeake Bay one century ago averaged 11,000,000 pounds per year. The average shad harvest in recent years averaged 385,000 pounds. Additionally, the blue crab is an economically important species for the lower basin. In 2001, the dockside value of blue crabs caught in or near the Rappahannock River was $1,857,626 (Virginia Marine Resources Council).
Water supply for residential, commercial, industrial and agricultural uses constitutes a major use of the river. The residential category includes single-family houses, townhouses, apartments and mobile homes. Residential water uses include water for drinking and cooking, toilets, showers, washing machines and dishwashers, filling swimming pools and irrigating lawns and gardens. The industrial category includes businesses engaged in manufacturing, and the commercial category includes businesses other than those engaged in manufacturing (retail, wholesale, service industries). Industrial and commercial water uses vary by business but generally constitute water associated with a production process or delivery of a service. Agricultural water uses represent water use for irrigating crops and watering livestock. Table 1 illustrates water withdrawal and consumptive use for the Rappahannock Basin for 1995 for residential, commercial and industrial uses only. Residential water withdrawals constitute 94.1 percent of total withdrawals and 61.0 percent of consumptive uses of water for 1995. Commercial withdrawals and consumption are 81.5 and 88.4 percent greater respectively than industrial water withdrawals and consumption (US Geological Survey 2001).
Table 1: 1995 Rappahannock River Basin Withdrawals and Consumptive Uses
(million gallons per day)
(million gallons per day)
Rapid economic and population growth in the middle basin (Stafford and Spotsylvania Counties and the City of Fredericksburg) of the Rappahannock are causing increases in residential, commercial and industrial water withdrawals. Based on historical population counts, Stafford County and Spotsylvania County have experienced an average population increase per decade of 50.87 percent and 53.72 percent respectively since 1950 (Weldon Cooper). In comparison, the state of Virginia has experienced an average population increase per decade of 16.37 percent (Weldon Cooper). The population growth in the middle basin impacts the entire basin because withdrawals in the middle basin could change the ability of other localities to obtain permission to withdraw water in the future because Virginia still operates under the riparian principle of water allocation. The riparian principle dictates that water is plentiful and available to all property owners (Mississippi-Alabama Sea Grant Legal Program). Therefore, under the riparian principle, disputes over rights to a limited water source are settled through litigious disputes.
Due to the brackish, tidal nature of the water in the lower basin, local planners are not concerned with ensuring rights to withdraw water directly from the river for consumptive uses but rather are concerned about the environmental consequences as a result of increased withdrawals upstream. Water supply for residential, commercial and industrial use in the lower basin comes from groundwater, and the relationship between groundwater and surface water is a possible concern because decreased stream flow in the river will impact groundwater levels and thus impact lower basin water supplies for consumption. Additionally, if the salinity level were to rise beyond normal fluctuation patterns because of increased water withdrawals further upstream, the native flora and fauna may not be able to exist in such an environment. As a result, the lower portion of the river may experience a shift in species composition (US Geological Survey 2002). Among the species changes, economically important species such as blue crabs may cease to live in the tidal areas of the river, and anadromous fish such as shad that use the tidal areas as a highway to the spawning grounds further upstream may be turned off at the high salinity levels. The upper basin is also concerned about maintaining minimum in-stream flows for anadromous fish spawning.
Water withdrawal permitting and the diversity of population create an atmosphere of conflicting interests between water utility managers in different locations who compete with each other for rights to withdraw water and ecological concerns, and between water managers and environmental interests at the federal, state and local level over how much water must be left in the river to maintain environmental and ecological integrity.
The Rappahannock River Basin Commission (RRBC) was created in 1998 to address these management challenges. The birth of the RRBC was the result of a Rappahannock Basin study panel established by the General Assembly in 1996. The panel recommended to the General Assembly that a commission was needed to provide “a mechanism for coordination and communication for the multitude of…activities that influence the Basin’s natural resources” (Mudd, p.1). The RRBC was tasked with coordinating and communicating water quality and water quantity concerns. Before the establishment of the RRBC, local and regional agencies addressed concerns of how the water in the river was going to be allocated and whether there was going to be enough to support all of the activities that depend on the water from the river. Until the RRBC was established, however, communities and agencies concerned with different geographic areas or different uses of the river did not have one central place to discuss their concerns (Mudd).
Currently, the RRBC is heading a basin wide water supply planning project to identify how to satisfy different consumptive and non-consumptive uses of the River now and for the future. The focus of this study is to address peoples’ concerns about how water will be allocated “and whether there’s going to be enough (water) to support the river itself, along with all the activities that depend on water from the Rappahannock” (Eldon James, Commission Coordinator in Mudd, p. 2). The Commission is pursuing the water supply planning project using shared vision planning including the use of a shared vision model.
The RRBC computer simulation model maps the hydrology of the two main surfacewater systems in the basin (the Rappahannock River and the Rapidan River), the impoundments (reservoirs) and demands from residential, commercial and industrial uses. The model has been developed with stakeholders and adapted to meet stakeholder concerns to ensure that everyone involved in the process is familiar with how the model works. Figure 4 is the general conceptual structure of the RRBC model.
Figure 4: Conceptual Structure of the Rappahannock River Basin Shared Vision Model
Specifically, the model is comprised of two main elements, supply and demand, and results (supply minus demand) are reported on a monthly time step. The supply section of the SVM calculates river flows under different historical hydrological conditions, reservoir management plans and water withdrawals. The demand section of the model calculates the amount of water needed to satisfy residential, commercial, industrial and agricultural water requirements. Demand is a function of the number and type of water users (population, employees, irrigated acres), the intensity of the water use (per capita, per employee or per acre use), and seasonal variations of water use. The blue arrows represent stream flows of the river system (supply). The green arrows represent outflows from the river system (demand). The assumptions about the elements of the model (stream flow, population, per capita use) are called parameters. The RRBC’s shared vision model relies on user inputs of the parameters in order to calculate future water supply and water demand (gray boxes in Figure 4). Now that the basic supply and demand system is modeled the stakeholders will continue to develop the model to incorporate their interests and concerns, such as environmental functions.
The shared vision planning effort, which incorporates the shared vision model, currently underway for the Rappahannock River Basin is a unique opportunity where stakeholders from all parts of the basin are coming together to plan for the future of the basin in an unhindered collaborative manner.
Commission Plans and Statistics
2600 Washington Ave 3rd Floor. Newport News, Virginia. Weldon Cooper Center for Public Service.
(2001). Census of Population 1790-1990.
2004 Info: http://www.mrc.state.va.us/newsletters/cfn_spring05.pdf
\Mississipi-Alabama Sea Grant Legal Program
(July 2002). Water Quantity Disputes.
(February 2002). From Ravensden Rock to Stingray Point, The Rappahannock RiverDraws Attention. Virginia Water Central Newsletter. No. 2.
Rappahannock River Basin Atlas and GIS Database
Soil and Water Conservation Tributary Strategy for the Rappahannock River and Northern Neck Coastal Basins
(April 2002). Department of Conservation and Recreation sponsored site.
US Geological Survey
(July 2001). 1995 Water Use Data.
US Geological Survey
(2002). Seasonal/Yearly Salinity Variations in San Francisco Bay.
Virginia Department of Game and Inland Fisheries
(2002). Rappahannock River.
Virginia Marine Resources Commission
(2002). Plans and Statistics Data for Rappahannock River and Tributaries. Requests can be made through the Virginia Marine Resources.
(1995-2002). Rappahannock River Valley National Wildlife Refuge.
Portions of the Rappahannock River Basin are experiencing rapid economic and population growth. Recognizing this trend, and foreseeing the potential for conflicts over different uses of the water resources, the Rappahannock River Basin Commission is pursuing a collaborative planning process to ensure that increasing consumptive water demands are met while protecting the ecological integrity of the river and its tributaries within the basin. This planning process specifically pursues cooperation between representatives of different (potentially competing) interests who have a stake in the outcome of the planning process.
Stakeholders in the Rappahannock River Basin shared vision planning process include local water utility managers: town/city managers and developers from all the counties in the basin; federal environmental regulators and representatives from the Army Corps of Engineers, U.S. Environmental Protection Agency, and the U.S. Fish and Wildlife Service; state environmental regulators and representatives from the Virginia Department of Game and Inland Fisheries and Virginia Department of Conservation and Recreation; and local environmental advocates. These stakeholders are invited to meetings organized by the Rappahannock River Basin Commission to discuss and collaborate on the specific issues of concern to the various stakeholders in planning for water supplies for the next fifty years.
At this point, the stakeholders are still ambitious and realize the long-term nature of this planning process. Due to budgetary constraints the process has slowed down a bit but should pick back up once budget tensions ease.
Rappahannock River Basin Commission website. The website includes links to download several papers that have been written related to the planning process (look under “Water Allocation Group”). http://www.rappriverbasin.org
Most recent Stella© shared vision model for the Rappahannock River Basin Commission study.
(You must have Stella© version 7 or higher to view the model. To download a demo version of Stella© go to http://www.iseesystems.com/community/downloads/STELLA/STELLADemo.aspx)