Alyson Fauske, Sr Municipal Project Manager, WSB
As of May this year, many states are experiencing abnormally dry conditions with some regions in drought. These drought conditions significantly impact municipal water supplies which leads to water restrictions.
The type of water that cities supply to their residents is treated for a number of economic and environmental reasons. Cities measure the annual average demand and peak demand, but drought conditions like we’re experiencing now, fall outside of annual averages.
During drought conditions many cities implement additional water restrictions, and many residents don’t understand how these restrictions can help restore water levels within a matter of hours. Although it doesn’t seem like limiting irrigation or water use would have much of an impact, it significantly improves a city’s supply.
Enacting water restrictions alleviates the demand and can prevent communities from falling below fire protection and boil water levels. The diagram below shows an example of a water tower’s levels in a week. Water towers have censors that measure elevations. There is a minimum water level within the water tower to provide adequate fire protection. In our example, that level is 21 feet, meaning if there were a fire and the water tower level was below 21 feet there may not be adequate supply to fight the fire.
There is also a minimum level that needs to be maintained in the water tower to ensure that the pressure in the system is high enough to keep contaminants from entering the water system. In our example, if the water elevation drops below 10 feet a boil water notice would be implemented.
There are several actions that communities are taking today to help limit water usage including developing water reuse systems and plans, adjusting landscaping to include more native, drought resistant plantings and grasses, and reducing overall water consumption.
Instances of severe drought remind us that water is not a limitless resource and that forces outside of our control can have major impacts on our infrastructure.
With 20 years of engineering experience in the municipal industry, Alyson Fauske has built her career providing municipal engineering services throughout the Twin Cities. Her portfolio of work includes street and utility reconstruction, technical analysis and field observations, direct project planning and management, and comprehensive and capital planning services.
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