Flow nets yield more information than just seepage rates. For example, the total energy head at an~ location in the flow net can be estimated using equipotential lines. Recall that equal head drop occur from the reservoir water level to the tail water level in sequential equipotentia lines. Given the total energy head at any point, the pressure bead can be obtained by subtracting the position head. In addition, the magnitude and direction of the seepage velocity can be estimated at any film net location using total bead differences from adjacent equipotential lines and measured distance ~ from the scale drawing. With this background, estimate the total energy head and the seepage velocity (magnitude and direction) at locations I, 2, and 4 in Figure 7.28 (b). Assume the upstream water depth is 160 ft (which also acts as a scale), K = 7 . 02 ft/ day, and the porosity is 0.40. The bottom of the reservoir is the datum from which total energy heads will be measured.