Thanks to a recently passed law every county in Virginia must plan to have adequate and sustainable water available for all their businesses and citizens. Water is our most valuable resource and how we manage its use or allow its abuse may determine the fate of mankind. The earth's total water supply is vast, estimated to be about 333 million cubic miles of water, over 96 % of which is saltwater. Fresh water represents only 4% of the total water of the earth. Over two thirds of the freshwater on earth (68%), is locked up in ice and glaciers (until they melt), about 30% of freshwater is in the ground as groundwater, and surface-water sources, such as rivers, streams and lakes, only represent about 2% of the fresh water and 1/10,000th of 1% of the total water on earth. The fresh water available on earth for mankind to use is finite, though constantly renewed by rainfall and snowmelt. Groundwater supplies can become polluted or be overdrawn and the soils through subsidence can lose the capacity to store water or be recharged.
According to the US Geological Survey about 26 % of the freshwater used in the United States in 2000 came from ground-water sources; the other 74 % came from surface water. Groundwater is an important natural resource and in nature serves to supply base streamflow during dry periods. Groundwater is a renewable resource, but not in the way that sun light is. Groundwater recharges at various rates from precipitation and other sources of infiltration.
The US Geological Survey estimated that the nation receives about a trillion gallons of recharge to the groundwater aquifers each day. (USGS circular 415). The recharge is not spread evenly across the nation or even where the water is needed. There limits to the amount of groundwater available for extraction from the aquifer. The amount of groundwater removed from an aquifer needs to be sustainable and should ideally match the recharge rate.
Groundwater availability and recharge rates vary locally and regionally and can be impacted by man. Over pumping of groundwater in the Costal Plain has lowered the groundwater tables for both aquifers. In the confined artesian system, the result has been salt water intrusion in areas. Development often is characterized by pavement and building that prevents the infiltration of precipitation that occurred before development.
In some regions groundwater that is currently being pumped was stored in the aquifer a millennia ago when the climate in that area was wetter. That water is not being replaced under current climate conditions and may ultimately be used up. Centralized wastewater systems further compound the problem by collecting the used groundwater, treating it and releasing the water into a stream or to the ocean in costal areas rather than distributed infiltration back into the ground by septic systems.
Our freshwater resources need to be managed as a whole. The utilization of groundwater resources in an unsustainable manner can result in impacts to the entire region, including the decrease in water level and aquifer storage, reductions in stream flow and lake levels, loss of wetland and riparian ecosystems, land subsidence, saltwater intrusion and changes in groundwater quality. Each watershed is unique and must be managed individually, and the data necessary to understand and manage water resources must be gathered locally over time to track and respond to changes in groundwater quantity and quality as well as stream flow.
This past winter the Virginia Legislature passed SB 211 which was signed into law by the Governor. This bill amends the enabling legislation for comprehensive planning to emphasize availability, quality and sustainability of groundwater and surface water resources on a County level as part of the comprehensive plan.
Comprehensive planning is already required and is not new. Groundwater and surface water are protected under current legislation. This bill makes one change to current law: in preparation of a comprehensive plan, the local planning commission must consider not only groundwater and surface water; but groundwater and surface water availability, quality and sustainability.
This bill carried by Senator Stuart and part of the legislative agenda endorsed by the Virginia Association of Conservation Districts Board of Directors on September 20, 2017 and ratified by the membership at their annual meeting in December 2017.
Virginia is dependent on groundwater. According to Virginia Tech there are approximately 1.7 million Virginians who get their water from a private well. In addition, according to the U.S. Geological Survey there are almost 750,000 Virginians who get their water from public and private community supply groundwater wells. In total that means that approximately 30% of Virginians are entirely dependent on groundwater for their drinking water.
Our other communities are dependent on surface water or a mix of groundwater and surface water. Surface and groundwater resources are limited. Having a comprehensive plan that lets people run out of water or has inadequate water to meet current or future zoning and planned development is not much of a plan.
Water resources can only be managed on a local level. There are already problems with availability, quality and sustainability of groundwater in Virginia in places such as Fauquier County, Loudoun County and the Coastal Plain. In addition, there is new information that was not previously available. Using their satellites, NASA can now measure groundwater depletion from space. They found that over the ten years (2003-2013) all of Virginia’s groundwater aquifers were being depleted, using groundwater faster than it was being recharged.
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