Frequently Asked Questions About Water
Q. Sometimes when it rains a lot, the water level in Carvins Cove doesn't increase. Why?
A. Carvins Cove is replenished by precipitation falling in the Carvins Cove, Catawba, and/or Tinker Creek watersheds, which are all north of the City of Roanoke. If it's not raining to the north of the city, the water level in the Cove won't increase.
In addition to rainfall location, two other factors and the time of year affect water capture. First, there is very little paved area in these watersheds. For runoff to occur, rainfall has to be greater than the soil can absorb. The soils in these areas have to be saturated before runoff will occur. In the winter, soils stay moist or are frozen, facilitating runoff.
Second, capture rates are different between summer and winter because the trees have leafed out. The leaves intercept the rain, allowing much of it to be evaporated back into the air. Tree roots also absorb more water in summer months; trees then transpire much water back to the air.
In addition to decreasing the amount of water captured, these factors increase the time it takes for water to flow into the Cove. The level response is not as quick in the summer as in the winter.
One other thing to remember - the shape of the reservoir is similar to a funnel. This means the storage volume is wider towards the surface than it is at the bottom. The closer the level gets to the top, the more water it takes to see an incremental increase in level. Therefore, when the level is very low, rainfall tends to increase the level faster than when the level is already fairly high.
Q. Why does drinking water have to be treated first? Isn't water all-natural?
A. Water itself is all-natural, but not everything in nature is good to drink. Untreated water may contain bacteria and other disease-bearing material. Water treatment removes these harmful contaminants and kills bacteria and other pathogens.
Q. What is in my tap water besides just water?
A. Tap water contains certain chemicals that promote health and a reliable water distribution system. In addition to a trace of harmless chemicals left over from the treatment process, your water contains chlorine (used for disinfection), fluoride (used to keep teeth healthy),and some systems contain orthophosphate (used to control corrosion in water pipes). For detailed information, see the 2007 Water Quality Report.
Q. Why does my tap water sometimes smell like chlorine?
A. Tap water contains soluble chlorine, which is constantly escaping as chlorine gas. This is the chlorine you smell, but the concentration is very small and will not hurt you. If you do not like the smell of chlorine, you can reduce the chlorine odor by filling a pitcher of tap water and letting it stand in the refrigerator overnight.
Q. Why does the Water Authority use so much chlorine?
A. We use only enough chlorine to ensure safe drinking water. Like any other business, it would be a waste of our money and your money to use any more chlorine than necessary. We have to put enough chlorine in the water at the plant to make sure we meet the minimum state standards for residual chlorine at any point in the water distribution system.
Q. Who regulates how my water is treated? Does the Water Authority meet appropriate standards?
A. Drinking water produced by the Western Virginia Water Authority is strictly regulated by the Commonwealth of Virginia. Our operators and laboratory technicians are certified by the state and are subject to frequent testing. We are proud to meet or exceed all state and federal requirements to provide you with drinking water of the highest quality.
Q. What causes tap water to be discolored? Is it safe to drink?
A. Changes in water pressure in the Authority’s water system can occasionally cause drinking water to be discolored. The discoloration is caused by sediments in pipes mixing with clear water; the sediments occur naturally from the oxidation of iron in pipes. While discolored water is ordinarily safe to drink, it is best to flush any discolored water from pipes by turning on all cold water faucets in your home or business. Avoid turning on hot water faucets so the discolored water is not drawn into hot water heaters.
One cause of water pressure change is from the use or flushing of fire hydrants. Fire-EMS and Utilities staffs occasionally flush hydrants to ensure that they are working properly and to flush sediments out of pipes.
Water pressure can also change in the event of water main breaks. If you notice evidence of a water main break or a leaking fire hydrant, please call 853-5700.
Q.I've noticed that the caps on the fire hydrants are painted different colors. What do these colors represent?
A. The Western Virginia Water Authority maintains over 4,000 fire hydrants in the City of Roanoke and Roanoke County. The hydrant caps are color coded to indicate the usual water capacity of each hydrant. This allows the fire department to quickly decide which hydrants are the best to connect to. We use a color scheme suggested by the American Water Works Association.
Blue Caps = 1,500 gpm (gallons per minute)
Green Caps = 1,000 to 1,499 gpm
Orange Caps = 500 - 999 gpm
Red Caps = Less than 500 gpm
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