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aspects of the total drainage basin. The uppermost por-

.tion of the drainage basin is actually located in the

center of the Transverse Ranges, a group of mountains

'which trend east-west and include the San Gabriel Mount-

ains, and are in opposition to the general northwest
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trend of the Coast Ranges (Carmen 1964). From the

uppermost section of its drainage basin the Piru Creek

drains southward descending rapidly to meander across an

area of gentle relief until it joins the Santa Clara River

near the town of Piru in Ventura Countye The Santa Clara

River in turn drains westward entering the Pacifj.c Ocean

just south of the city of Ventura.

There is at present one reservior on Piru Creek, the

San Felicia Dam, located about five miles upstream from

the confluence of the Piru Creek and thG Santa Clara

River. This dam impounds the runoff from about 425 square

miles of the drainage basin, however, this area will be

reduced once the Pyramid Rock Reservior, which is present-

ly under construction, becomes operational. This second
reservior loca~ed 6.5 miles upstream from the San Felicia

Dam is expected to act as cat.chment for about 285 square
miles of the upper sections of the lower portion of the

drainage basin. A third reservior is also being consider-

ed, this to be located at the southern end of the Hardluck

Valley, about five miles above the Pyramid Rock Dam.

The physiography of the area about Pyramid Rock is