Wake County Needs to Conserve Water

Submitted by Water Team on Tue, 06/03/2008 - 10:30am.
Water supplies available in Wake County are stressed and with growth will become inadequate. We will be forced to make unwelcome trade-offs between environmental protection and growth. Water conservation can extend the county's future growth capabilities and protect our aquatic ecosystems.

 

Current scenario: Projections that do not include water conservation1 show that, as the county's population grows, we will become more and more vulnerable to drought. Supply (safe yield2 of all sources) will be taxed by dry season demand3, and cannot meet maximum day demand during dry conditions, even as new sources become available. Before 2030, average day demand will exceed the point at which state guidelines require planning for new sources.

Current water demand graph

 

1. Average day and maximum day demand projections came from 2005-2006 update to Wake County Water and Sewer Plan.

2. Safe yield is the amount of water that can be continuously withdrawn during a drought of specified recurrence (in the case of N.C. reservoirs, 50 years) without drawing down a source below its usable level. Safe yield figures were taken primarily from the 2005-2006 update to the Wake County Water and Sewer Plan. However, published safe yield figures for some sources do not agree, and projected safe yields are subject to change.

3. Dry season demand is the gallons used per day averaged during the months of June through October. Ratio of average day to dry season demand was determined using use information from 2002 Cary and 2006 Raleigh water supply plans.

Conservation scenario: If we could conserve 20% of average day demand and 30% of dry season demand and maximum day use, supply would meet demand. Wake County could still grow and would be less vulnerable to the disruptions of drought. We could also delay the need for additional supply and extend the payment period for expensive new water sources.

 

Conservation water demand graph

Other reasons to conserve:

  • Climate change has a significant impact on the water supply. Dr. Peter Robinson, North Carolina's first state climatologist, has said North Carolina's summers have been getting drier while falls are getting wetter: "These differences can have a major impact on the occurrence of drought and on water supplies. Drier summers almost automatically mean that summer droughts are more frequent." 4

 

  • The amount of water available from Falls Lake is uncertain. Increases in downstream water use because of growth in the lower Neuse Basin could force more release from Falls reservoir.5 Raising the dam at Lake Michie (part of the Durham's current Capital Improvement Plan) would reduce the amount of water flowing to Falls Lake. In addition, groundwater use is decreasing the amount of water in streams that feed Falls Lake during dry periods.6

 

  • Wake County will have to show REAL conservation to receive permits for Little River Reservoir or more water from Jordan Lake or Kerr Reservoir. The State Environmental Policy Act requires efforts that will reduce the negative effects of projects that will increase growth and have environmental impacts. One such effort is water conservation.

 

Contact: Jeri Gray, jerigray@mindspring.com

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4. http://www.ncatlasrevisited.org/homefrm.html

5. "Water: Does the Triangle have enough to support growth?" U.S. Army Corps of Engineers Wilmington District News, July 2000.

6. "Groundwater Consumption Contributing to Loss of Low Stream Baseflow in Some Wake County Drainage Basins." The Voter, League of Women Voters of Wake County, February, 2003.