Water Resources Management in the Colorado River Basin

How Does Flow Alteration Propagate Across a Large, Highly Regulated Basin? Dam Attributes, Network Context, and Implications for Biodiversity

“…That river section exhibited small, smooth peaks in flow in March‐April instead of the large peaks in May‐June that would result from snowmelt under free‐flowing conditions (Figure S2 in Supporting Information S1). The alteration in peak flow timing likely relates to the timing of downstream water needs, particularly for irrigated agriculture, which continues to be the largest use in the CRB with more than half of the total consumptive use basin‐wide (Butler et al., 2021).…”

“…First, important management differences exist in the Upper versus Lower Colorado River Basins, and in the amount of water that is actively allocated (and thus “moved” from wet seasons to dry seasons) in each of the two management units. While the Upper Basin uses about half of its 7.5‐million‐acre fit allocation, demand in the Lower Basin grew hit its full apportionment by the late 1990s (Butler et al., 2021). The fact that most flow is accounted for, and the high degree of regulation and water residence time of the large dams in the lower Colorado main‐stem (Kumar et al., 2022), likely decreases R 2 values by temporally decoupling inputs and outputs at each reservoir.…”

“…The Colorado River system is operated under the “Law of the River,” a complex set of legal documents (e.g., treaties, compacts, statutes, regulations, and contracts) that are relevant to the allocation and management of waters in the CRB. A decline in river flows by nearly 20% (on average) relative to pre‐dammed conditions, and ongoing climate‐driven supraseasonal droughts, have led to overallocation of resources and significant management challenges (Butler et al., 2021). From an ecological standpoint, the CRB has some of the most unique and endangered fish communities in North America, resulting from long isolation and strong environmental gradients (Minckley & Deacon, 1968).…”

Preparing municipal water system planning for a changing climate: Integrating climate‐sensitive demand estimates

“…The climate‐sensitive simulation accurately reflected the imported water timing and magnitude due to limited surface water supplies, that is, increased imported water use through September. While we focus on an MWS, the projection accuracy of seasonal demands and imported water requests flows across water resources sectors, such as reservoir storage‐release operations, power generation, and multi‐stakeholder interests (Benson, 2018; Butler et al, 2021; Siirila‐Woodburn et al, 2021; Turley et al, 2022; Wei et al, 2022). With large reservoir systems storing water for many stakeholders, this works highlights a research need to explore the impacts of refined demand estimates (e.g., climate‐sensitive) on large water resources infrastructure management and operations in a changing climate.…”

Water: A Major Stake of Conflicts in the Twenty-First Century

“…After the controversies surrounding the dividing wall between the two countries (Demata, 2017), the issue of sharing water from the Colorado and the Rio Grande-known as the rio Bravo del Norte in Mexico, is amplifying the tensions between the two riparians (Figure 3). The Colorado River, a state in the United States [260,837 km 2 ], also refers to a river originating in the Rocky Mountains of the state of Colorado-more precisely in the Rocky Mountains National Park, crossing 5 American states [Colorado, Utah, Arizona, Nevada and California], providing drinking water to more than 40 million people, stretching for 2334 km before ending its course in Mexico and flowing into the sea (Butler et al, 2021). The Rio Grande, longer than the Colorado River, it forms the entire border between Texas and Mexico, half of the only land border between the South and the North [2000 km from El Paso to the Gulf of Mexico] (Lavariega Monforti & Graham, 2018).…”