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. 

Streamflow Data

• 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.

Runoff Contour

• 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

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