Water Quantity

Tue, 11/08/2011 - 09:50 -- cadoughe

Shortly after passage of the Clean Water Act, the Safe Drinking Water Act of 1974 was passed to protect public health by regulating the nation’s drinking water supply. The federal law, augmented by amendments as well as state laws and regulations, requires many actions to protect water and its sources including rivers, lakes, reservoirs, springs, and groundwater wells. Originally focusing on water treatment, it now also focuses on source water quality and conservation.

Overall, Western North Carolina has abundant rainfall, surface water, and ground water. The headwaters of the river basins in the region provide water to local residents and to distant southeastern cities. While supply has historically been more than adequate, recent droughts have raised public awareness of the issues of water use and conservation.

Water Supply and Use

Water supply and use

In 1990, data was collected for commercial, domestic, industrial, and agricultural water withdrawals. The average water withdrawal per day was 172 million gallons (this data does not account for water returned to the source after use). Buncombe, Henderson and Wilkes counties had relatively high commercial, domestic and industrial use while Haywood and Transylvania Counties had the highest industrial use.

In 2005, data collection methods changed, resulting in the collection of several more water withdrawal categories in addition to changes in the definitions of categories. In the most recent data, the public water supply category includes all uses supplied by residential, commercial, industrial and institutional uses in the public water systems. Domestic self-supplied captures residential well usage. The average water withdrawal per day in 2005 was 136 million gallons. Due to collection method changes, the charts presented here should not be compared on a one-to one basis, however, water use trends have been showing decreases in many areas due to changes in the manufacturing base of the economy, conservation practices, treatment efficiencies, leak detection, incentive programs, and public education. Also collected but not shown here are withdrawals for aquaculture (961 million gallons per day) and thermoelectricity (262 million gallons per day). In these operations also, much of the water withdrawn is returned to the source after treatment a short distance downstream.

Many municipal water supplies in the region depend, at least partially, on watersheds in the Pisgah, Nantahala, and Cherokee National Forests, lands which were set aside a century ago for the purpose of protecting water supply. The national forests are high quality sources of clean water because these forests mainly grow under conditions that produce relatively reliable water runoff and yield water relatively low in contaminants when compared with many urban and agricultural land uses.

In much of the rural parts of the region, ground water is the sole resource for drinking water. The depths of wells normally range from 20 to 1,200 feet. With increasing population, many more wells are being drilled, and information on this important resource is not well documented. Small towns dependent on wells from local fractured-bedrock aquifers are concerned about sufficient water supply to support economic development and population growth.