This publication presents precipitation data collected by the Flood Control District of Maricopa County's automated ALERT system. This telemetered flood-detection network is located primarily throughout Maricopa County, Arizona with additional gages in Yavapai, Pinal, Gila, and La Paz Counties.

The data contained in this report was collected, compiled, and edited by the Flood Warning/Data Collection Branch of the Engineering Division. Precipitation data includes daily, monthly, and annual totals for 208 stations maintained by FCDMC.

Information contained herein is as accurate and complete as possible within the limitations of real-time ALERT data collection technology currently available. Wherever possible, footnotes have been included to identify questionable, estimated, or missing data. Reliance upon the accuracy, reliability, or authority of this information is solely the responsibility of the user.

This report is Volume 1 of a 5 Volume set entitled "ALERT Annual Hydrologic Data Report". Volumes 2-5 in order are [2] Surface Water Report; [3] Observer Network; [4] Stormwater Monitoring Program; and [5] Weather Data and Alluvial Fan Watershed Summaries. Additional copies of this report, or copies of the companion volumes, may be purchased from:

or downloaded from our World Wide Web page at: