To determine the residual pressure available at a flow of 1,000 gpm (3,785 Lpm), locate the 1,000 gpm point on the horizontal axis of the water supply graph and trace vertically to intersect the residual pressure curve.
Then, read the corresponding pressure value on the vertical axis. Based on the exhibit provided, the residual pressure available at 1,000 gpm flow is approximately 42 psi (2.9 bar).