A Brief Overview of the Rio Grande Compact 04/26/06

A Brief Overview of the Rio Grande Compact 04/26/06

The New Mexico Interstate Stream Commission Investigate, Protect, Conserve, and Develop the State s Waters and Stream Systems Negotiate and Administer Interstate Compacts Oversee Development of Regional Water Plans & State-Wide Water Plan Federal Issues Management (Endangered Species Act water issues)

The Upper Rio Grande Basin

Background Late 1800 s Drought and Increased Irrigation Diversion in Colorado 1896 Federal Embargo on Water Development 1906 Treaty of 1906 1916 Elephant Butte Reservoir Operational Early 1920 s Federal Water Development Embargo Lifted Late 1920 s Middle Rio Grande Conservancy District Construct the MRGCD diversion dams, canals, drains, and El Vado Reservoir

Background (Continued) 1929 Interim Rio Grande Compact Sets limits on depletions of water 1935 El Vado Reservoir Completed Supreme Court Lawsuit by Texas 1935-1937 Rio Grande Joint Investigation 1938 Rio Grande Compact Signed, Supreme Court Lawsuit dismissed

The Rio Grande Compact Signed in 1938 in Santa Fe following those four decades of controversy to: Effect an equitable apportionment of the waters of the Rio Grande above Ft. Quitman, Texas Remove all causes of present and future controversy Promote interstate comity

The Rio Grande Compact The Compact apportions the waters of the Upper Rio Grande Basin amongst the three States The Compact does not affect the obligations of the United States to Indian Tribes or impair their Rights San Juan-Chama Project Water is not subject to Compact apportionment

The Rio Grande Compact - Colorado Colorado is Required to Deliver Water to New Mexico at the Stateline

The Rio Grande Compact - Colorado

The Rio Grande Compact - Colorado COLORADO ANNUAL COMPACT ALLOCATION - RIO GRANDE 1400 1200 ANNUAL COMPACT ALLOCATION (1000 a 1000 800 600 400 In above average year, flow in excess of 560,000 acre feet must be delivered to New Mexico. Available for Depletion in Colorado Colorado Delivery Obligation to New Mexico 200 0 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 ANNUAL FLOW AT DEL NORTE (1000 af)

The Rio Grande Compact - Colorado COLORADO ANNUAL COMPACT ALLOCATION - CONEJOS RIVER 700 600 ANNUAL COMPACT ALLOCATION (1000 a 500 400 300 200 In above average year, flow in excess of 224,000 acre feet must be delivered to Rio Grande. Available for Depletion Delivery Obligation to Rio Grande 100 0 0 100 200 300 400 500 600 700 ANNUAL CONEJOS RIVER INDEX SUPPLY (1000 af)

The Rio Grande Compact New Mexico New Mexico is Required to Deliver Water to Texas at Elephant Butte Reservoir based upon flow at Otowi Bridge

The Rio Grande Compact New Mexico

Middle Rio Grande Compact Allocation and Obligation 3000 ANNUAL COMPACT ALLOCATION CHART 2800 2600 ANNUAL COM PACT ALLOCATION (1000 acre-feet) 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400 In above average year flow in excess of 405,000 acre-feet must be passed below Elephant Butte Reservoir New Mexico Delivery Obligation to below Elephant Butte Dam 200 Available for Depletion above Elephant Butte Dam in New Mexico 0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 ANNUAL INFLOW AT OTOWI (Otowi Index Supply, 1000 acre-feet)

New Mexico s Compact Compliance 300 Rio Grande Compact Cumulative Delivery Departure 1940-2006 200 Departure in Thousands of AF 100 0-100 -200-300 -400 2006 Credit = 37,100 AF -500-600 1940 1950 1960 1970 1980 1990 2000 Time (Calendar Years)

New Mexico s Compact Compliance NMISC Goal Maintain compliance while allowing for efficient and effective use of the available supply Status in Compliance since the late 1960 s Activities Middle Rio Grande Project Operations of the Low Flow Conveyance Channel ISC/Reclamation Coop Agreements River System Maintenance Metering and Modeling Pilot Channel Work Other SJC Water Depletion Offset and Municipal Pumping

Rio Grande Floodway in 1952 Looking downstream from south boundary of Bosque del Apache (courtesy of Reclamation)

Compact Storage Restrictions If We Accrue Deliveries to Texas: Water Must be Retained in Storage in Post- 1929 reservoirs to the extent of the debits and cannot be used If Usable Storage in Rio Grande Project Reservoirs is low: cannot increase the amount of native water stored in post-1929 reservoirs An accepted Relinquishment allows for some upstream storage

The Compact and Elephant Butte Reservoir Colorado and New Mexico Credit Water is held in Elephant Butte Reservoir Spills from Elephant Butte Reservoir eliminate credits and debits

The Rio Grande Compact - Texas From Elephant Butte Reservoir to Fort Quitman, Texas 57% of the Rio Grande Project Supply delivered to New Mexican s

The Rio Grande Project

The Rio Grande Project Delivers water to the Republic of Mexico and irrigable lands in New Mexico and Texas During full allocation years, Reclamation delivers about 931,800 AF at diversion dam canal headings with a reservoir release of 790,000 AF Hudspeth County Irrigation District is not part of the Rio Grande Project

RIO GRANDE PROJECT STORAGE 2,500,000 Maximum Available Storage Capacity 2,000,000 ACRE-FEET 1,500,000 1,000,000 500,000 0 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Note: Storage values as of Jan 1 each year. Elephant Butte and Caballo Reservoirs included in analysis. Value for Jan 1, 2005 is estimated