Risk Management, Conservation and the Basin Study Eric Kuhn, GM A N U PPER B ASIN P ERSPECTIVE ColoradoRiverDistrict

Basin Study Results More than 1 in 5 climate change traces post 2040 show a “Lee Ferry deficit” post 2040 show a “Lee Ferry deficit” (1 in 12 of all traces) (1 in 12 of all traces) Conservation in the Upper Basin with a Conservation in the Upper Basin with a “Water Bank” is an effective strategy to “Water Bank” is an effective strategy to reduce Lee Ferry deficits reduce Lee Ferry deficits

Under Article III.c. of the 1922 Compact, the Upper Division states shall not cause the flows at Lee Ferry to fall below 75maf/any consecutive 10 years Under Article III.c. of the 1922 Compact, the Upper Division states shall not cause the flows at Lee Ferry to fall below 75maf/any consecutive 10 years The Upper Basin has an undefined obligation to the Mexican Treaty under Article III.c. The Upper Basin has an undefined obligation to the Mexican Treaty under Article III.c. What is a Lee Ferry Deficit? - plus - The Basin Study assumed 75maf/10 years

Could lead to a legal curtailment under the 1922 & 1948 Compacts Could lead to a legal curtailment under the 1922 & 1948 Compacts A curtailment could shut down post Compact uses such as cities & power plants - with serious economic consequences A curtailment could shut down post Compact uses such as cities & power plants - with serious economic consequences Article VIII of the 1922 Compact: present perfected rights... are unimpaired by this Compact Article VIII of the 1922 Compact: present perfected rights... are unimpaired by this Compact Implications of a Lee Ferry Deficit

To ↑ flow at Lee Ferry must ↓ consumption To ↑ flow at Lee Ferry must ↓ consumption In Western Colorado 90% of agricultural CU is hay, pasture grasses & alfalfa In Western Colorado 90% of agricultural CU is hay, pasture grasses & alfalfa In Western Colorado 90% of municipal CU is outdoor use (parks & lawns) In Western Colorado 90% of municipal CU is outdoor use (parks & lawns) Conservation strategies for in-basin uses different than for exports!

Strategies to Manage Risk of a Curtailment Use CU from pre-compact rights to survive a curtailmentUse CU from pre-compact rights to survive a curtailment Use CU from conservation of agricultureUse CU from conservation of agriculture & municipalities to avoid a compact & municipalities to avoid a compact (grass management) (grass management) Many, many issues to resolve!Many, many issues to resolve!