Arizona Water Science Center
PROJECT MENU
USGS IN YOUR STATEUSGS Water Science Centers are located in each state. |
Lower Colorado River StudiesIn 1960, the U.S. Geological Survey began its studies of the lower Colorado River and has worked continuously along the river since that time. The lower Colorado River is the reach of the river from Lees Ferry to the international boundary with Mexico, although most of the studies concentrate in the area downstream from Davis Dam where agriculture is the main use for water along the river. The primary goal of all the studies is to collect hydrologic data, increase our understanding of the hydrologic system, and develop methods to enable the Secretary of the Interior to meet the specific responsibilities stated in the U.S. Supreme Court decree, 1964, Arizona v. California, to account for consumptive use of water from the mainstream of the Colorado River. Annual data in all the studies providing information for decree accounting are based on the calendar year. Beginning in the 1980's, most of the studies were done in cooperation with the Bureau of Reclamation. Lower Colorado River Interactive MappingAn ongoing project by the U.S. Geological Survey (USGS), in cooperation with the Bureau of Reclamation (Reclamation), involves inventorying all the wells and river pumps located within the river aquifer along the lower Colorado River and providing that data for use with the accounting-surface method. Many of the observation wells in the area downstream from Laguna Dam were inventoried in 1994. From 1995 to 2003, the inventory concentrated in the area upstream from Laguna Dam. In June of 2003, the inventory began again in the area downstream from Laguna Dam and has since been ongoing in both reaches of the river. Priority is given to wells that yield water that is consumptively used for public supply, irrigation, and domestic purposes. In 2000, the river aquifer in California was designated by Reclamation for priority completion. Data entry to the USGS National Water Information System (NWIS) is an ongoing process, so the data available can increase daily. Site and water-level data are available on the Web within one day of entry to NWIS. The accounting surface was updated in 2008 and the two areas previously described in the original the accounting-surface method reports WRIR 94-4005 (Wilson and Owen-Joyce, 1994) and WRIR 00-4085 (Owen-Joyce and others, 2000) were combined into one area. The coverages used to produce the maps were combined so this updated web page now parallels the maps illustrated in the updated report SIR 1008-5113 (Wiele and others, 2008). The interactive Web page was created to provide a means for users to combine the site and water-level data graphically with the map coverages from the reports to create maps. Coverages are provided as either boundary lines or color coded polygons. The well and river pump data shown on the interactive Web pages are point coverages and will be updated quarterly in January, April, July, and September. The coverages provided for base data are from USGS digital line graph (DLG) data sets. The relief map was generated from USGS digital elevation model (DEM) data sets. Maps created by a user can be printed or saved to files. By using the icon buttons at the upper left of the screen, the user can zoom and pan, select individual data points, or select a group of data points within a user drawn polygon. The data for the selected points will appear in a table at the bottom of the screen. Only the most recent measured water level is displayed. To see more water levels, use the NWIS Web page shown above. Because of Federal guidelines on the release of sensitive water-related information, use of water data are not available at this time. NWIS also contains information on springs and gaging stations. A coverage showing springs in the area upstream from Laguna Dam was added to the Web page in October 2003. A coverage showing gaging stations was added to the Web page upstream from Laguna Dam in November 2003 and includes an active link on the Site ID to the NWIS real-time streamflow data. The interactive mapping Web page for the Laguna Dam to Mexico reach was added in February 2004. A newly digitized Colorado River coverage was added in July 2006. A new hillshade overlay in the background was added the first quarter of 2008 and the updated accounting surface was added in October 2008. Please keep checking back for additions to the Web pages. References
|