Volume (\( V = A_0 d + \frac{177 d^2 \sqrt{A_0}}{S} \)):

Where:

• \( V \) is the volume of storage, in cubic length (L³).
• \( A_0 \) is the area at the spillway crest, in square length (L²).
• \( d \) is the depth of water above the spillway crest, in length (L).
• \( S \) is the average slope of the reservoir sides and banks, in percent (%).