Page:California Highways and Public Works Journal Vols 8-9.djvu/25



Salinity investigation

The regular 76 salinity observation stations that were maintained during the summer have been reduced to 30 of which 26 will be continued as all year round stations as agreed at the conference of the Advisory Engineering Committee held on September 24, 1920.

The regular drainage water stations are to be maintained until further notice. Additional tidal cycle salinity measurements were taken at locations where the desired salinity content and tidal characteristics could be obtained. Due to deficiency of precipitation the river has not increased in flow to an extent that warranted additional tidal cycle stream flow measurements in the various channels. The maintenance of the tide gages has continued and will be maintained throughout the winter. Analytical studies of stream flow and tidal data on relation of salinity thereto have been continued. Statistics on the growth of storage developments on the Sacramento and San Joaquin rivers have been completed.

Salt Water Barrier A program covering the investigation and study of the economic as well as the physical aspects of the Salt Water Barrier below the confluence of the Sacramento and San Joaquin rivers has been tentatively adopted. However, the final set-up of procedure will not be determined until it has been reviewed and adopted by the joint State-Federal Commission. The tentative program is designed to include :


 * 1) An investigation and study of other possible sites and types of structure.
 * 2) A study of the relation of the proposed barrier at the several sites to industrial, irrigation and reclamation developments; domestic water supply; flood control; navigation; fish industry; and other items in order to determine the benefits or detriments that would accrue in each particular instance.
 * 3) An analysis to determine the economic feasibility of the barrier in relation to the various elements enumerated above.

The entire plan of the investigation is prepared with a view of evaluating the benefits that would be derived from the barrier and determining whether they would be commensurate with its cost. Until these economic features are thoroughly analyzed the relative value of a salt water barrier located below the confluence of the Sacramento and San Joaquin rivers as a unit in the state-wide plan of water development remains undetermined.

Six men are now employed on this investigation, five men in the office and one in the field. The field work has consisted of the collection of data on reclamation and irrigation developments in the area tributary to Suisun and San Pablo bays.

Bulletin No. 17, Southern California Preliminary draft of five chapters of Bulletin 17 has been prepared and submitted to the consulting board, which will meet on December 17th in Los Angeles for the purpose of reviewing the report. If these chapters receive the approval of the committee they will be forwarded to the print shop immediately. One chapter yet remains to be drafted and submitted to the consulting board.

Santa Ana Investigation The work on measurement of percolation from rain-fall on the valley floor, measuring of stream runoff, rising water and losses in the stream and the work on transpiration from seeped areas, cultivated areas and areas in native vegetation has continued. In addition to this work it appeared on further study of the legislative enactment of the legislature of 1929 that further investigations into the plan of conservation of the water of the Santa Ana River were authorized and it was decided to take up the matter of spreading on the Santa Ana cone and on the various cones westward thereof belonging to the small creeks discharging on to the Cucamonga plain. Only work of a preliminary nature has been done to date, but a survey party will be In the field shortly to take topography, and it may be necessary to do some aerial mapping on the smaller streams.

Mojave River Investigation Aerial survey of the entire area involved has been completed. Gaging stations on the two upper forks and at the lower site have also been completed. A map is being prepared of the valley.

Santa Maria River Stations have been established on Sisquoc River, Cuyama River above the mouth of Huasna Creek and on Huasna Creek. The matter of a more general investigation into the ground water conditions in the valley has been further investigated and a program involving the expenditure of $2,000 a year in addition to the maintenance of the above stream gages has tentatively been laid down.

Salinas River Stations have been established on San Antonio Creek near the mouth and on Salinas River near the city of Salinas. The previous intention to place a gaging station on Nacimiento Creek was changed because it was difficult to get a station on that creek, and San Antonio Creek will, it is believed, give a similar unit run off, enabling an estimate of the water supplies from the west side to be made from the records as well as such an estimate could be made from the Nacimiento Creek records.

Santa Margarita Creek Maintenance of the stations at Nigger Canyon and Temecula Canyon have been taken over as a part of the water resources investigation.