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14 and directly east of the eastern edge of the irrigated area. This location of the drain will have two major advantages over a drain located in the "sump" area: (1) The drain will be closer to the irrigated area and thus laterals constructed to serve the iITigated area will be two or three miles shorter than they would be if the drain were located in the "sump". (2) Water having a high sodium content, which occurs in parts of the "sump" proper, will not bscome a part of the recovery of the drain. The drains which are in operation at the present time have a quality that is well within the limits set by the Compact. Further, laterals of the San Luis, Costilla, Excelsior, Prairie, and Farmers Union Canal aystems, will cross the Drain and tailings from these laterals, not needed for use on lands east of the Drain, will empty into it as fresh water. < As to the quantity of water that will be recovered by the Drain, while I believe under ultimate conditions, at least 60,000 acre-feet per annum will be returned to the river in addition to that which reaches the river at the present time, by no means will that emount be returned when the Drain is initially constructed. It seems reasonable to assume, however, that at least 30,000 acre-feet will be returned. Prior to the time when laterals are constructed to the Drain, the water recovered. by it will be mad.e up of three items: Na~ural drainage recovery along the line of the Drain, waste from irrigation laterals, and drainage water from existing drains. The proposed Drain is 37 miles long. It is reasonabls to assume that the recovery per mile will be in the neighborhood of 300 to 320 acre-feet per annum. This is one-half of the recovery of drains con- structed through irrigated areas in the Valley. Natural recovery, therefore, should emount to at least 12,000 acre-feet per annum. About 170,000 acre-feet of water will be diverted annually to those irrigation systems which have laterals that will tail into the Closed. Basin Drain. The tailings probably will vary from five to ten per cent of the total diversion, which will mean about 8,500 to 17,000 acre- feet of fresh water from this source. The recovery from ex- isting d.rains, which will empty into the Closed Basin Drain largely during the winter, is estimated at about 6,000 acre-feet per annum. From 26,000 to 35,000 acre-feet, there- fore, seems to be a reasonable estimate of the yield. of the Drain when it is initially constructed. However, this is purely an estimate and there should not be too much specu- lation concerning the performance of the Drain until the investigation which 'has been initia~ed, is completed, 1162 ;, ., " I I ~.