WATER STOKAGE ON SWEETWATER AND SAN JACINTO RIVERS. 389 



HEMET CEEEK. 



The stream issuing from Hemet Valley in the San Jacinto Mountains is locally 

 known as Hemet Creek or South Fork of San Jacinto River. It drains an area 

 above Hemet Dam of 66 square miles of rugged mountain watershed, from 4,300 to 

 9,000 feet in elevation, and has in ordinary seasons a minimum flow of about 200 

 miner's inches, or 4 cubic feet per second. The watershed is fairly well clothed with 

 forest trees of pine and oak. and the mountain sides are generally covered with dense 

 underbrush where the forest trees are not in evidence. The stream is the largest of 

 the three principal tributaries that unite before issuing from the mountains to form 

 San Jacinto River. The entire watershed area of the river above the mouth of the 

 canj'on is 143 square miles, and the proportio!i intercepted by the Hemet Dam is 

 therefore 45 per cent of the whole. The San Jacinto is a typical southern California 

 torrent, deserving of the name of river only at certain rare intervals when seasons 

 of heavy rainfall produce a run off of such volume as to enable it to fill two large 

 lakes which lie along its source, and which when tilled finally ovei-flow and seek an 

 outlet to the sea by joining the Santa Ana River at Rincon, below South Riverside. 

 The first of these lakes is located in the great San Jacinto Valley, about 15 miles 

 northwest from the mouth of the canyon, and is a broad, shallow lagoon of large 

 capacity. Before reaching this pond the river must traverse a broad, porous bed of 

 sand and gravel which is capacious enough to swallow up a ver\- considerable stream. 

 In ordinarj' seasons the river does not reach all the way to the lagoon before being 

 absorbed in these thirsty- gravel beds. When the seasons are wetter the river may 

 reach the lagoon and fill it partiall}' or wholly. Anj- water oveiHowing the lagoon 

 must then pass southwesterly across the San Jacinto Valley on a very flat slope, 

 filling more gravel beds on the way. and thence through a rocky canyon to Elsinore 

 Lake, a total distance of 25 miles in an air line from the lagoon, or about 40 miles by 

 the channel. If the season is extremelj- wet the run ofl' may suffice to fill the lake and 

 overflow to the Santa Ana. a further distance of 25 miles, and thus make a continuous 

 connection from the mountains to the sea; but this occurs at such rare intervals as to 

 be phenomenal whenever it does happen. 



The fluctuating character of the stream has rendered it of little A"alue as a source 

 of supph' for irrigation, prior to the construction of the Hemet Dam in 1890-1895. 

 The onlj- diversions from the main river below the mouth of Hemet Creek, prior to 

 the commencement of construction of the dam were an 8-inch steel pipe line, carrying 

 water to the Florida tract, a ditch with a capacity of about 3 to 4 cubic feet per 

 second supplying a farm nearest to the mouth of the canyon, and a few flood-water 

 ditches down the stream above the lagoon for meadow irrigation, which received a 

 precarious and uncertain supply. 



No diversions had ever been made of Hemet Creek proper, the stream to which 

 my inquiries were confined by my instructions, before the building of the dam. 

 Hemet Vallej' above the dam is a frostj' region where crops can not be profitablj' 

 i-aised on account of climatic severity, and hence it is devoted to grazing. The outlet 

 to the vallej- is a narrow, rock}- gorge some 9 miles long, cut in granite, in which the 

 stream plunges down a descent of 2,000 feet before uniting with Strawberry Fork. 

 The masonrj- dam is at the head of this gorge, and water from the reservoir is 



