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Of course, giving1 these totals for the two different seasons of the year, I have endeavored to get the average run­off during each period for each creek, talcing into considera­tion only the average mean flow during good seasons, which have "been obtained from the observation of the water marks on the creek banks,, and the statements of old settlers along the banks of the respective rivers, and I am convinced that in every case this average is rather too low than too high. In connection with this run-off, we have to take into consideration the storage capacity of the reservoir, and since forj every day of run-off there is also a daily discharge from the stores of the reservoir, we will adopt the policy, in order to get a capacity and results from this enterprise, of deducting from the daily flow during the summer seasons, the amount of water necessary for our purposes, and store the surplus in the reservoir at Long Valley, to add to the daily flow during the winter months a sufficient amount of water to have an equal discharge of the reservoir every day during the entire year. Since we have adopted this policy, the storage reservoir is only necessary to carry the amount of water required for six months, because the other six months the high water stage will take care of itself. Having in the daily run-off from these streams combined, a surplus after the daily duty of the reservoir has been performed, the storage capacity of the reservoir, with a dam of a height of 300 feet, would be 5000 second feet of daily discharge for six months. In order to come to a unit for the capacity of this enterprise, I adopt a daily run-off and discharge from the reservoir of 3500 second feet, which would give a daily surplus 7