Question

A lake with a surface area of 1260 acres was monitored over a period of time. During a one-month period, the inflow was 36 cfs, the outflow was 30 cfs, and a 1.6-in seepage loss was measure. During the same month, the total precipitation was 4.3 in. Evaporation loss was estimated as 6.0 in. Estimate the storage change for this lake during the month

Answer 1

ΔS = 115.5 ac -ft

Step-by-step explanation:

A = 1260 acres, T = 1 month , I = 36 cfs , O = 30 cfs , P = 4.3 in , G = 1.6 in , E = 5 in

ΔS = I - O + P - G - E

Converted inflow

36 ft³ / s * 1 ac / 43560 ft² * 12 in / 1 ft = 9.9173 x 10 ⁻³

9.9173 x 10 ⁻³ * 3600 s / hr * 24 hr / 1 day * 30 day /month = 12852.89256

25705.78512 * 1 / 1260 acres = 20.40 in

Out flow

30 ft³ / s ⇒ 17.00 in

Replacing

ΔS = 20.40 - 17.0 + 4.3 - 1.6 - 5 = 1.1 in

ΔS = 1.1 in * 1 ft / 12 in = 0.09126

ΔS = 0.09126 * 1260 acres = 115.5 ac -ft