Colorado River Basin

The 1922 Colorado River Compact divided 7.5 million acre feet per year to each of the Upper and Lower Basins at Lee Ferry, Arizona. The 1928 Boulder Canyon Project Act then split the Lower Basin into Arizona 2.8 million, California 4.4 million, and Nevada 0.3 million acre feet, and the 1944 treaty promised Mexico 1.5 million.

Add it up and the Law of the River apportions about 16.5 million acre feet against a natural flow that averaged roughly 14.6 million from 1906 to 2023, and just 12.9 million from 2000 to 2024. The Congressional Research Service states it plainly: apportioned Colorado River water exceeds the river’s natural flows.

Reclamation publishes a weekly hydrologic update, and the late-August 2026 numbers are stark. As of August 23, 2026, Lake Powell held 5,194 thousand acre feet at 22 percent of capacity and Lake Mead held 6,928 thousand acre feet at 27 percent. Total Colorado River system contents stood at 18,453 thousand acre feet, 32 percent of capacity, against 22,263 thousand acre feet and 38 percent one year earlier.

Lake Mead reached 1,040.50 feet on August 7, 2026, breaking the previous record low of 1,040.58 feet set in July 2022, the lowest since the lake filled in the 1930s. It has continued to fall since.

The inflow picture explains why: forecast water year 2026 unregulated inflow to Lake Powell was 3,584 thousand acre feet, 37 percent of normal, and observed April through July inflow was just 1,143 thousand acre feet, 18 percent of normal.

This is the single most useful price disclosure in western water, because it is a federal agency publishing what it pays, per acre foot, by name of participant.

Reclamation’s System Conservation Implementation Agreements pay on a term schedule: $330 per acre foot for a one-year commitment, $365 for two years, and $400 for three years. The published table covers 23 participants, 1,563,194 acre feet, and $663,611,984 in total commitments, funded under the Inflation Reduction Act.

The 2007 Interim Guidelines and 2019 Drought Contingency Plans both expire at the end of 2026, and their replacement is now signed. Reclamation published a Final Environmental Impact Statement on July 31, 2026 and a Record of Decision on August 21, 2026 covering coordinated operations of Lake Powell and Lake Mead for 2027 through 2036.

The framework allows annual Powell releases between 5.0 and 12.0 million acre feet, a Lower Basin shortage allowance up to 3.0 million acre feet, and conserved-water storage capacity of 8.0 million acre feet in Powell and 3.0 million in Mead, plus voluntary Upper Basin conservation up to 200,000 acre feet.

For 2027 specifically, Lower Basin deliveries are cut by 1.25 million acre feet: Arizona 760,000, California 440,000, and Nevada 50,000 acre feet, alongside at least 700,000 acre feet of voluntary conservation across the two-year period.

Two legal constraints shape this basin more than any others, and both cut against the obvious plays.

Arizona bars interstate export of its own apportionment. A.R.S. section 45-292 requires Director approval to transport water out of state and provides that the Director shall not approve transporting water allocated to Arizona by federal law or interstate compact. Compact and treaty deliveries are exempt from the article, but the practical effect is that Arizona Colorado River water is not an interstate commodity.

Colorado’s anti-speculation doctrine bars acquiring water rights primarily to profit from a future sale or lease. A state working group specifically flagged buyers acquiring agricultural land with the primary intention of enrolling in a program that pays water rights holders not to use the water. Buying in to flip into a conservation payment is exactly the pattern the doctrine targets.

Some of the largest and most durable leases in the basin are tribal, and recent federal law expanded that.

The Colorado River Indian Tribes Water Resiliency Act of 2022, signed in January 2023, authorizes CRIT to lease, exchange, or store part of its 662,402 acre foot per year first-priority entitlement off reservation. The Gila River Indian Community leases about 121,000 acre feet per year, more than a third of its Central Arizona Project supply, to other users, and separately holds the second largest conservation agreement in the published Reclamation table.

For a non-tribal owner the lesson is comparative: these are the counterparties setting the scale and the price expectations in Arizona, and any valuation should account for that supply.

Arizona SB 1611, signed in 2025, lets landowners in the Phoenix and Pinal Active Management Areas permanently relinquish grandfathered irrigation rights in exchange for groundwater savings credits that count toward assured water supply requirements. The state projects it will conserve nearly 10 million acre feet over its life.

This is a genuine new monetization path for irrigation rights in Arizona’s growth corridors, and it is structurally different from a lease: it is permanent relinquishment in exchange for a credit that developers need. Owners weighing it should price the credit against what the same water could earn on a term lease before committing to something irreversible.