||22 IS UTAH SAHARA BOUND? The Mt. Pleasant Flood The $106,000 Mt. Pleasant flood of July 24, 1946, was the most violent of twelve summer floods that have descended upon this community of 2500 people since the occurrence of the first flood in 1893.23 It seems most significant to me that this community was unscathed by floods during the first half century of occupancy whereas during the last half century it has been damaged twelve times. The causes of the change in the run-off characteristics of this formerly non-flooding drainage basin are etched on the denuded and gullied headwater slopes. In its investigation of the 1946 Mt. Pleasant flood the Forest Service* found that the intense portion of the flood-producing storm covered only 5,200 acres or about one-half of the 11,400 acres in the drainage basin. The amount and intensity of the precipitation is not known precisely, but within the intense storm area newly cut channels, gullies and rills showed that run-off was confined almost entirely to about 1,210 acres of seriously deteriorated range. Intermingled, but well vegetated sites withstood the full fury of the storm and yielded no flood run-off. Thus, the real cause of this flood was not the storm but, rather, the denuded condition on parts of the watershed. Watershed abuse is costly. For the $106,000 damages of the 1946 flood to citizens of Mt. Pleasant, there must be charged to every abused acre within the storm area of Pleasant Creek the sum of $87.60. It should be remembered also that most of this flood source area is public land. In 1946 a few stockmen obtained 2,565 animal unit months of grazing for their livestock within the Pleasant Creek drainage basin. It is estimated that this grazing use realized for the stockmen a cash income of $1,282 or the equivalent of an income of 11 cents per watershed acre. For the privilege of obtaining this income from the publicly owned portion of the watershed the stockmen paid to the public a grazing fee of five cents per acre. On the other side of the ledger, the records show that the accumulated damage of floods to Mt. Pleasant over the past 50 years amounts to 35 cents per acre per year for the entire Pleasant Creek watershed and to $2.35 per acre per year for the deteriorated portion of the watershed from which those floods have come. What sort of bookkeeping is this? Unfortunately these figures on dollar values, as disturbing as they are, present only minor aspects of the water problem. Our soil-laden streams, or gullied hillsides, our flood-ravished towns are only outward manifestations of deeper and more basic troubles. The real problem of water conservation in Utah lies in the widespread and accelerated erosion of watershed soils. No more urgent problem than this confronts our inland empire today. Nothing is more likely to determine the economic health of our state a hundred years hence than the measures we adopt to restore our depleted mountain soils, and especially the speed with which we apply these corrective measures. *Local floods, Pleasant Creek Watershed, 1946. A memorandum report on file, Intermountain Forest and Range Experiment Station, Ogden, Utah.