Upload
phamthuan
View
215
Download
0
Embed Size (px)
Citation preview
INSIGHT INTO CONTINUING CHALLENGES ON THE
COLORADO RIVER
2015 AWRA Annual Conference Jim Lochhead – CEO/Manager – Denver Water
• The Colorado River travels 1450 miles through 7 states and Mexico to the Sea of Cortez
• It supplies water to 40 million people and 5.5 million acres of agriculture.
• $1.7T in gross municipal product = 12th economy in the world
• Total use 80% agricultural, 20% M&I • The system relies on two large
regulating reservoirs: – Lake Powell in the Upper Basin – Lake Mead in the Lower Basin
Colorado River System
• Divided the Colorado River, including all tributaries, into an Upper and Lower Basin
• Boundary between the two basins is Lee Ferry, Arizona • Lower Basin states: Nevada, California and Arizona • Upper Basin states: Wyoming, Colorado, New Mexico and Utah • Arizona, Utah and New Mexico have lands within both basins
1922 Colorado River Compact
Total Allocation of 18 MAF • 8.5 MAF to the Lower
Basin – 4.4 MAF to California – 2.8 MAF to Arizona – 0.3 MAF to Nevada – 1 MAF from LB
tributaries • 7.5 MAF to the Upper
Basin – 51.75% to Colorado – 23% to Utah – 14% to Wyoming – 11.25% to New Mexico
• 1.5 MAF to Mexico
4
Colorado River Compacts and Treaty
Colorado River Compact signing
An over-allocated river Colorado River water supply vs use
Built-in imbalance and problems
• Upper Basin: Hydrologic leftovers – Upper Basin to not
deplete flow at Lee’s Ferry below 75 MAF over running 10 yr. average
– Over allocation, growth and climate change all combine to create uncertainty of supply for Upper Basin
“Bath tub ring” at Lake Powell
Built-in imbalance and problems • Lower Basin: Structural Deficit
– Inflow into Lake Mead = 9.0 maf (8.23 maf release from Powell + side inflows) – Outflow = -9.0 maf (AZ, CA, NV and Mexico Delivery – System and evaporative loss = -1.2 maf – Deficit = -1.2 maf
Given basic apportionments in the Lower Basin, the allotment to Mexico and an 8.23 maf release from Lake Powell, Lake Mead declines about 12 feet/year.*
*Bureau of Reclamation
Collaboration to create flexibility
Key accomplishments • 1996 – Interstate banking – NV in AZ • 2001 – Interim Surplus Guidelines • Quantification Settlement Agreement – CA down to 4.4 maf
allocation • 2007 Shortage Sharing/ Interim Operating Guidelines
– Resolves operating issues – Upper Basin tied to Lower Basin structural deficit
• 2012 – Minute 319 brings Mexico into shortage sharing and adds NGOs to discussion
Historic drought continues
Current Storage
Percent Full MAF Elevation (Feet)
Lake Powell
51 12.4 3606
Lake Mead
38 9.9 1079
Total 45 22.3 n/a
As of November, 2015
Contingency planning
• CRSP reservoir operations • Demand management • Colorado River System Conservation Plan
– Provides up to $11 million funding for at least two years to develop, test and gather data on short-term water-saving pilot programs to benefit water levels in lakes Powell and Mead
– Temporary, voluntary and fully-compensated programs – Programs should be designed to reduce consumptive use of
water – All water conserved under this program will be treated as river
system water. The saved water will not go directly to the program funders or other water users
– Pilot programs already underway