Streamflow data, including average seasonal flow, average annual flow and other information are shown in Table 7.2-2. Flood ALERT equipment in the basin is shown in Table 7.2-3. Reservoir and stockpond data, including maximum storage or maximum surface area, are shown in Table 7.2-4. The location of streamflow gages identified by USGS number, flood ALERT equipment, USGS runoff contours and large reservoirs are shown on Figure 7.2-4. Descriptions of stream, reservoir and stockpond data sources and methods are found in Volume 1, Appendix A.
- Refer to Table 7.2-2.
- Data from three stations located at two watercourses are shown in the table and on Figure 7.2-4.
- Average seasonal is highest at most stations in the winter (January-March) or spring (April-June).
- The largest annual flow recorded in the basin is 5.7 million acre-feet in 1993 at the Gila River below Gillespie Dam station with a contributing drainage area of 49,650 square miles. Gillespie Dam was breached during the 1993 flood.
Flood ALERT Equipment
- Refer to Table 7.2-3.
- As of October 2005 there were nine stations in this basin.
Reservoirs and Stockponds
- Refer to Table 7.2-4.
- The basin contains one large reservoir, Painted Rock, with a maximum storage of 4,831,500 acre-feet. This reservoir is used for flood control and is only filled during flood events.
- Surface water is stored or could be stored in two small reservoirs in the basin.
- There are 24 registered stockponds in this basin.
- Refer to Figure 7.2-4.
- Average annual runoff is highest, 0.2 inches per year or 10.66 acre-feet per square mile, in the southernmost portion of the basin and decreases to 0.1 inches, or 5.33 acre-feet per square mile, in the remainder of the basin.
Table 7.2-2 Streamflow Data for the Gila Bend Basin
Table 7.2-3 Flood ALERT Equipment in the Gila Bend Basin
Table 7.2-4 Reservoirs and Stockponds in the Gila Bend Basin
Figure 7.2-4 Gila Bend Basin Surface Water Conditions