TMWA delivers water to approximately 450,000 customers across extremely hilly terrain. From the foothills to the valley floor, the variation of high and low elevations makes managing water pressure a complex task.
In fact, there are 279 distinct pressure zones within TMWA’s service territory and each receives water at a certain pressure gradient. To deliver water at reliable pressures across this landscape, TMWA has a network of pipes, storage facilities, pumps, valves and pressure regulation devices—among other equipment.
“While the pressures in our system can fluctuate between 25 and 125 pounds per square inch (psi), a typical household will have a safe pressure range between 40 and 100 psi,” said Eric Mothershead, TMWA’s operations maintenance supervisor. “What can make this difficult to regulate is the difference in elevation between a water storage source and the ultimate customer location.”
For example, the highest elevation point in TMWA’s system is the Mt. Rose 3 tank at 6,676 feet, which is higher than the rim of Lake Tahoe at 6,225 feet). The lowest elevation point in the system is 3,983 feet, representing 2,600 feet between the high and low points in our system.
To be clear, there is no single water source in TMWA’s system that drops 2,600 feet to the end user. However, if your home is in a low-lying area, you should have a pressure-regulating device protecting your household plumbing from higher pressures. Correspondingly, if you live at a higher elevation, there’s a good chance TMWA is pumping uphill some or all the water you use.
“The goal is to make sure pressure is sufficiently strong at higher elevations and not too strong in lower areas,” Mothershead said. “There are places where we have to take the pressure down from over 300+ psi to under 65 psi in order to serve our customers without stressing their household plumbing,” Mothershead added. “On the low end, we try to maintain at least 40 psi in lower-pressure areas—while also maintaining adequate flows for fire crews when needed.”
If you have a concern about water pressure at your home or business, please contact a plumber.