Laserfiche WebLink
<br />. <br /> <br />. <br /> <br />p <br /> <br />. <br /> <br />Agricultural Use <br /> <br />Water for agriculture is one of the oldest and most important <br /> <br />uses. Diverting rivers and streams to irrigate crops provided <br /> <br /> <br />an economic foundation for early civilizations. Today, agriculture <br /> <br /> <br />accounts for over 807. of the consumptive water use in the Nation. <br /> <br />Therefore, it is not surprising that agriculture should be the <br /> <br />focus of much of the attention directed towards water conservation. <br /> <br />Agricultural water conservation opportunities may be categorized <br />under off-farm and on-farm losses. Off-farm conveyance system <br /> <br />losses include such things as reservoir evaporation and seepage <br /> <br />to' ground water from unlined canals and aqueducts. , Further, water <br /> <br />is lost to phreatophytes, which are deep-rooted relatively thirsty <br /> <br />plants such as willows and salt brush. In addition, operational <br />spills and any outflows to rivers and streams are losses to the <br />system. The average efficiency for off-farm conveyance systems <br />within a drainage basin is below 75% (the percentage of the water <br />diverted which is delivered to the farm) in a major port,ion of <br />the western United States. with only a relatively small number <br />reaching 907. efficiency. _/ These off-farm conveyance system <br />efficiencies can be increased by reducing losses, but not without <br />related costs. <br /> <br />On-farm irrigation systems suffer similar losses, including <br />seepage from unlined ditches, phreatophyte and hydrophyte (aquatic <br />plants) usage and over-irrigation. The application of water in <br />