Water supply sources, hydrant flow test methodology, extrapolating a supply curve from field data with the 0.54 exponent method, and determining whether a public main is adequate or a fire pump is required.
Every hydraulic calculation later in this program assumes a specific quantity of water is actually available, at a specific pressure, at the point the system connects to its source — water supply is the first design decision every other decision depends on, not a preliminary formality. This module covers where that water comes from (public main, on-site storage tank, fire-pump-boosted supply), how a two-hydrant flow test measures static, residual, and flow (pitot) pressure, and how field measurements are extrapolated into a usable supply curve.
A full worked example anchors the module in real numbers: extrapolating a flow test's single measured point (80 psi static, 55 psi residual at 1,000 gpm) out to roughly 1,600 gpm available at a 20 psi residual, using the same 0.54-exponent method this program's hydraulic calculations module (Module 5) and fire pump module (Module 7) both build on directly.