Imperial Valley press., 1908-04-04

tteIt dSdlh Aut SAtAHS AhNCtASAt Wlbh the proper condition for weir meas urement without end contractions. The nashboards are 1 inch thick and with continual use their corners become rounded so that they often do not give a good bottom contraction to the jet. Two tables are furnished to the zanieros for their convenience in set ting the gates. One of these is for the first two cases and is the table for pressure" measurements. It con tains the discharge in cubic feet per second per square inch of opening for heads which vary by one-half inch. In the submerged opening the effec- tive head is the difference between the heads above and Deiow the gate. The other table is for overpour meas urements and contains the discharge in cubic feet per second at various heads for each inch of length of weir. The zanieros are instructed to set the gates to the nearest onyhalf inch and no finer division is made. The maxi mum error in the head is therefore one-fourth inch. Tn an overpour or suppressed weir measurement with the length of the weir feet and the head one fourth inch too low, at 6 inches the calculated discharge would be 3.53 cubic feet per second, which would be an error of OPP cubic foot per sec ond, or an error of per cent. The zanjeros are required to record the head and dimensions of the opening in pressure measurement and the head and length of the weir in an over pour measurement. The head over the opening is taken as the head above the center of the opening. While the cubic foot per second is used as the unit of measurement by the companies the rate of flow in the small ditches is more commonly eeferred to in terms of the miners inch. The inch used in Imperial Valley is the one-Aftieth part of a cubic foot per second and is not the statute inch of California, which is defined by law as one-tortieth of cubic foot per second,
 While the measurements are not made with a high degree of accuracy, the companies are desirous of making improvements in this respect in tne future. The importance of proper measurements should not in any case be overlooked, but it may be said that refined measurements are not so neceS- sary in Imperial Valley as in many districts, on account of the abundant supply of water for all land under cultivation.
 When water was first brought into the valley no charge was made for 1t by the canal company, and later the minimum charge of 50 cents per acre was imposed, regardless of the amount used. At this time many matters were yet taking form, and the company en- outraged settlement in every way pos sible and assisted in the organization of the mutual water companies. Dur ing this early period there was rather reckless use of water, because of it's being free, and through lack of knowledge of what the requirements were, where the conditions were so unlike those of other irrigated dis tricts. The charge of 50 cents per acre-foot for water began July l, 1905, and since that time there has been more of an inducement for the water users to economize in the use of water The company has so far been liberal in the delivery of water and this lib erality has been transferred to the water users by the mutual companies. As the valley progresses, it is to be expected that there will be more limi- tation on the use of water, more ac- curacy in water measurement, and more economy on the part of the water