Laserfiche WebLink
<br />N <br />r-" <br />1-." II. HYDRO-SALINITY MONITORING AND EVALUATION <br />to- <br /> <br />The Lower Gunnison, Colorado unit illustrates the geo- <br />hydro-chemical process, where a salinity control unit is <br />underlain by a massive Mancos Shale Formation with an <br />unlimited salt supply. Irrigation water percolating <br />below the root zone picks up salt from an infinite <br />source. <br />This section addresses monitoring and evaluation of the <br />salt loading from the irrigated land and the impacts on <br />this through implementation of the CRSCP in this unit. <br /> <br />1. Summary of stream gauging data <br /> <br />Salinity of irrigation water delivered to the farms <br />averages 260 mg/L and drainage water returning to the <br />two Rivers averages 2650 mg/L, an assessment offered in <br />Salt Primer. Water and Salt Budaets, January 4, 1994. <br /> <br />Stream gauging data is of benefit, but because there are <br />numerous surface water drainages suppling water for <br />irrigation, it is not a simple matter to assess water <br />quality above and below the boundaries of this project <br />area. Stream guaging data collected and recorded is <br />published in Water Resources Data Colorado, an annual <br />hydrologic data report by the U.S. Geological survey. <br />The title also includes the "Water Year" and Volume 2. <br />Colorado River Basin, contains those sites which fall <br />within this salinity proj~ct area. <br /> <br />2. Irrigation monitoring and evaluation <br /> <br />Irrigation water delivery systems (earthen ditches and <br />canals) are numerous. A large number of off-farm <br />delivery systems exist. There are 2 federal and several <br />private canal systems. Some group systems are <br />incorporated; however, many are not. Size of systems <br />varies from 2 members to over 100 members. Most of <br />these are currently earthen ditches but approximately 39 <br />systems are currently being or are contracted to be <br />concrete lined or replaced with underground pipeline. <br /> <br />Many on-farm systems are also earthen ditches with few <br />or no improvements. Some farms have concrete ditch <br />lining and underground pipeline which were installed <br />prior to initiation of LGCU. 255 current contracts show <br />planned or implemented system improvements. <br /> <br />5 <br />