Fig. 1: Colorado River Basin map, hydrologic parameters, and representative geologic cross-sections.
From: Multidecadal drought impacts on the Lower Colorado Basin with implications for future management

This map illustrates the Upper and Lower Colorado River Basin, along with naturalized flow at Lees Ferry (km3/yr, 2002–2024, Supplemental Table 6), mean annual precipitation (P, km3/yr; 2002–2024; Supplementary Table 3b), runoff (Roff, km3/yr 2002–2024; Supplementary Table 5b), surface water (SW) and groundwater (GW) water withdrawals (WW) (km3/yr, 2000–2020, Supplementary Table 11). The Active Management Areas that receive CAP water (Phoenix, Pinal, and Tucson) are indicated, highlighting key groundwater management regions. Two cross sections are presented: A–A’ in the upper right and B–B’ in the lower right illustrate topographic and geological variations across the Plateau and alluvial basin physiographic provinces of the Lower Basin57.