How is water pressure affected by elevation in a plumbing system?

In a plumbing system, water pressure is influenced by elevation due to the concept of hydrostatic pressure. As you increase elevation, the weight of the water column above a specific point decreases, resulting in a decrease in the water pressure at that point. Specifically, for every foot of elevation gain, there is a corresponding pressure drop of approximately 0.433 psi (pounds per square inch). This relationship underlines why, in higher buildings or elevated tanks, the water pressure at the top is lower compared to the pressure at the base. Consequently, as elevation increases, the available water pressure decreases, which can lead to the need for booster pumps or other systems to maintain adequate pressure at higher elevations. Therefore, the correct statement about the influence of elevation on water pressure is that it decreases as elevation increases.