How the Rio Grande Compact Functions Water and Natural Resources - PowerPoint PPT Presentation

How the Rio Grande Compact Functions Water and Natural Resources Committee Meeting, Las Cruces New Mexico 10/15/13 Page 1 of 50

The Rio Grande Compact Covers the Upper Rio Grande Basin  The Rio Grande Compact of 1938 divides the surface waters of the Upper Rio Grande Basin amongst Colorado, New Mexico, and Texas  The Upper Rio Grande Basin  From headwaters of Rio Grande in Colorado to Fort Quitman, Texas  The basin includes parts of the 3 states and two countries

Platoro Dam in Colorado

The Rio Grande Compact - Colorado • Colorado is Required to Deliver Water to New Mexico at the Colorado-New Mexico Stateline – At the Lobatos Bridge • The amount of water required to be delivered to the Stateline is determined based upon the gage record of: – The Rio Grande at Del Norte – Three locations on Conejos River System

The Rio Grande Compact - Colorado Del Norte Lobatos Conejos System Source: Colorado DWR

The Rio Grande Compact – New Mexico Upper Rio Grande Basin of New Mexico If depletions change between the Stateline with Colorado and Otowi Bridge, modify Middle Rio Grande allocation

The Rio Grande Compact in NM – Upper Rio Grande

The Rio Chama Valley below Abiquiu Dam

The Rio Grande Compact – New Mexico Middle Rio Grande Basin of New Mexico New Mexico is Required to Deliver Water to Elephant Butte Reservoir (the Rio Grande Project): There is an explicit allocation of the flow measured at the Otowi gage and delivery to Elephant Butte

Otowi Gage

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

Rio Grande Compact Compliance 1940 - 2013 300 200 100 Accrued Credit/Debit (KAF) 0 -100 -200 -300 -400 -500 -600 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 There is no approved accounting for 2011 and 2012. Under all proposed accounting methods New Mexico remains in an accrued credit status. Time (Calendar Years)

Middle Rio Grande River System Depletions Reservoir Evaporation Riparian 21% Total Mean River 37% Urban Depletions: approximately 5% (groundwater depletion 613,000 acre-feet per year with wastewater offset) 37% Crops Source: SSPA, July 2000 Water Supply Study of the Middle Rio Grande

The Rio Grande Compact – New Mexico Lower Rio Grande Basin of New Mexico Prior to the 2008 Operating Agreement, 57% of the Rio Grande Project Supply used in New Mexico