Project Details

The update of the San Tan West ADMS is in the mapping phase. The study area is located in the southeast corner of Maricopa County and extends into Pinal County. The watershed is divided into three distinct areas; 14 square miles of generally flat and undeveloped land in the towns of Gilbert and Queen Creek and unincorporated Maricopa County; 16 square miles of generally mountainous and undeveloped land in Pinal County that drains directly across the county line; and 5 square miles of undeveloped, mountainous land that drains to a distinct watercourse before flowing into Maricopa County. The 14 square mile area is newly mapped at 2-foot contour interval for 2-D flood hazard modeling. The 16 square mile area is newly mapped at 4-foot contour interval for 2-D hydrologic modeling of the distributary flows patterns. HEC-1 will be used to determine the hydrology for the 5 square mile area using existing mapping.

We are planning to advertise the next phase for this project in February, 2019. We will have new mapping for the entire watershed and continual updating of the Data Collection Report and the H&H models, followed by an Area Drainage Master Plan (ADMP) effort to identify alternative solutions for mitigating some of the flooding hazards for this watershed. One public meeting has been held, and a second public meeting is planned for the beginning of the next phase. We anticipate the second phase to be completed within 36 months after NTP has been issued.