http://www.twdb.state.tx.us
http://wiid.twdb.state.tx.us
http://www.twdb.state.tx.us/gwrd/waterlevels/waterlevels.html
http://www.twdb.state.tx.us/gwrd/waterwell/well_info.asp
http://greenleaf.unl.edu/
http://www.epwu.org/water/water_resources.html
http://www.ibwc.state.gov/Water_Data/rio_grande_WF.html#Stream