Of course, the main influence on streamflow is precipitation runoff in the watershed. Rainfall causes rivers to rise, and a river can even rise if it only rains very far up in the watershed-remember that water that falls in a watershed will eventually drain by the outflow point.
One US gallon of water weighs 133.526464 ounces. The calculations for that answer are below: 1 gallon = 8.345404 pounds 1 pound = 16 ounces 8.345404 X 16 = 133.526464.
One fluid ounce of water weighs 1.043 dry ounces or 0.0652 pounds, and is 29.574 grams. This is ONLY true of WATER. A fluid ounce of another substance WILL NOT WEIGH THE SAME AMOUNT! A fluid ounce is measure of volume, and a dry ounce is a measure of weight. Additionally, a gram or kilogram is a measure of mass, which should not be confused with weight or volume.