From Salt River Project:

Early this morning (Sept. 23), thunderstorms formed over the lower Salt reservoirs, including the Woodbury burn scar.  Radar precipitation estimates and gauge totals indicate 4-6 inches of rain accumulated in a relatively short time (4-6 hours).

In turn, significant runoff entered Canyon Lake, resulting in the need to pass storm water through Mormon Flat Dam, Stewart Mountain Dam and into the Salt River.  Release from Stewart Mountain dam peaked around 48,000 cfs at 10 a.m.  These releases will continue to move downstream causing a similar spill over Granite Reef dam and into the normally dry Salt River channel.

These flows will likely continue downstream impacting low water crossings such as Gilbert Rd. and McKellips Rd.. SRP’s Surface Water Resources group has stabilized reservoir elevations and are currently reducing releases from Stewart Mountain Dam.

However, threats of additional showers and thunderstorms exist into Tuesday, posing a risk of additional inflows into the lower Salt reservoirs that may require additional releases from Stewart Mountain Dam.   Due to this potential, SRP will open its Water Emergency Reservoir Operations Center (WEROC) to monitor the weather and make and needed changes to Reservoir levels and releases.

See the SRP daily water report