Reservoirs

(Published September 2005)

Both Northumberland and Lancaster Counties face a looming water crisis. Our two sources of artesian water are being consumed at an unsustainable rate, and the water quality in both artesian supplies is locally problematic for some citizens.

About a quarter of our citizens use shallow wells that tap the shallow, or water-table aquifer. Although the water is commonly acid and can contain iron, properly constructed and maintained wells can provide a sustainable supply of potable domestic water for scattered homes. Shallow wells are susceptible to bacterial contamination and should be tested periodically, and can contain levels of nitrate high enough to be dangerous to infants. If the well has not been tested for nitrate, bottled water should be used for infants.

Water levels in the principal artesian aquifer, typically at depths greater than about 600 feet, are declining more than a foot each year and are now about 50 feet below sea level. A half-century ago, water levels were about 30 feet above sea level. When water levels fall to so-called “management level” or about 80% of the depth to the top of the aquifer, the well should no longer be used. As we withdraw potable (fresh) water, we increase the likelihood that saline water will begin to enter the well. It is very difficult to predict accurately when either of these scenarios will begin to affect local wells. I will not be surprised if saline intrusion is detected in wells in the Windmill Point area in the very near future. Other wells may provide sufficient water for about a century, although many will need to be re-drilled and the pumps set at greater depths as water levels fall.

Fortunately, we have a simple solution to this problem, namely to set aside “canyons” for reservoirs. Sites for reservoirs were identified throughout the Northern Neck in an engineering study conducted in 1969. Multiple reservoirs will be needed. The best reservoir sites are located along the spine of the Northern Neck, but the population growth is in the “Coastal Fringe” especially along the Bay, necessitating that some of the reservoirs will need to be interconnected.

A sewage treatment system is being installed in Callao, so we can use Callao as an example of how a Village could be supplied with a sustainable water supply from a reservoir. The dam creating the Lodge Creek Reservoir (named after someone who donated land or spearheaded the project?) could be seen from, and south of US 360, and would be about 45 feet high. The water level in the reservoir, brim full, would be at about 40 feet above sea level. No homes are present at that elevation, and the nearest home is at an elevation of about 60 feet. No useful or developed property would be flooded, only the steep unbuildable canyons. The reservoir would have an area of about 118 acres and it could supply at least one million gallons per day safely, enough for at least 10,000 people. In 1969, land acquisition and construction, not including water treatment and distribution facilities, would have cost about $200,000. Today the cost exceeds $1,000,000.

Aside from providing a sustainable water supply, the reservoir would be an economic engine to create waterfront property and provide for recreation. Waterfront property would need to adhere to strict Bay Act-like restrictions in order to protect the public water supply. A “Resource Protection Area” several hundred feet wide and extending from the high water level should consist of mature trees with an overlapping leaf canopy and associated ground cover. Fertilized lawns should be banned, as should impermeable cover like asphalt. Pruning would be allowed between buildings and the water as long as a complete leaf canopy (and complete root mass) was maintained so the roots could intercept the groundwater. Power boating would be limited to electric or low horsepower 4-cycle gasoline engines. Commercial lodges, restaurants and fishing camps would be encouraged and, of course, the reservoir would be stocked with fish. Timbering rather than agriculture would be encouraged in the watershed, and agriculture would need to operate under strict Best Management Practices and realistic Nutrient Management Plans to protect water quality. A source of reliable irrigation water might encourage new kinds of agriculture.

Both Lancaster and Northumberland Counties face the same problem of declining water levels in the deep artesian aquifer caused primarily be water usage outside the Northern Neck. The two counties should work together on this issue because of potential cost savings. Lancaster County has a special incentive because the water quality in the deep artesian aquifer in southeast Lancaster County is the worst in the Northern Neck, and because Lancaster County needs the Mill Creek Reservoir south of Wicomico Church.

Reservoirs cannot economically supply water to all citizens, but rather only to those citizens on public water supplies in Villages and along major highway corridors. As citizen stewards we should all conserve as much artesian water as possible, which will lengthen the life of the aquifer for those unable to connect to a public supply from a reservoir. Water conservation in the home also increases the efficiency of septic systems.

It is inevitable that reservoirs will eventually be needed, and the sooner we think through all the issues involved and reach consensus, the less it will ultimately cost and the more benefits will accrue to all citizens of both counties. Several Stewardship Tips in this web site address water quantity and water quality in our local aquifers and additional information is available at http://northernneck.us.