280 likes | 435 Views
Active Water Resource Management in the Lower Rio Grande. TOOLS FOR A NEW ERA IN WATER MANAGEMENT. presented by Peggy Barroll, Hydrologist New Mexico Office of the State Engineer Lower Rio Grande Water Users Association 8/19/05. This Presentation. More details on the problem
E N D
Active Water Resource Management in the Lower Rio Grande TOOLS FOR A NEW ERA IN WATER MANAGEMENT presented by Peggy Barroll, Hydrologist New Mexico Office of the State Engineer Lower Rio Grande Water Users Association 8/19/05
This Presentation • More details on the problem • How will our draft regulations address this problem • The basis for administration
The Problem • Demand and use of water is increasing • Groundwater use is increasing • Junior Groundwater use impacts senior surface water rights
The Facts We Must Deal With • Groundwater and surface water behave as single resource • State Engineer Reynolds did not declare state’s jurisdiction over most of the LRG’s groundwater until 1980 and 1982 • Most pumping already established
The Facts We Must Deal With • Groundwater pumping has been increasing in the LRG • Groundwater pumping for irrigation use alone may be as high as: • 50,000 -100,000 AFY in full project supply years • 200,000 - 300,000 (?) AFY in low project supply years
Drain Flows are Part of the Water Supply of the Rio Grande Project • Historically drain flows have added about 20% to Project diversions • When the drains are dry, the Rio Grande Project water supply is reduced, and Project water cannot be delivered efficiently • Surface water rights associated with the Rio Grande Project are senior in priority
This Effect has been Evident in the Recent Drought • Groundwater pumping has been high during the recent drought • The drains have been dry • The drains dried up rapidly, and have not yet recovered.
To Address this Problem:The State Engineer is Increasing Regulation of Groundwater Use • Metering Order • District Specific Regulations • Enforcement against over diversion
In Addition, the District Specific Regulations Will Include Priority Administration • Junior groundwater rights will be curtailed in priority, as necessary • to protect the historical operations of the Rio Grande Project • to ensure protection of senior surface water rights owners
The Regulations Depend on a Priority Administration Target • This target has been set as the historical operating efficiency of the Rio Grande Project since the 1950s (the D2 curve) • Once a new operating agreement is developed, and is accepted by all parties, the State Engineer will administer to that agreement
What is D2? • D2 is a plot of Project Release vs. Project Supply Using data from 1951-1978 • Project Release: Water released from Caballo for the Rio Grande Project • Project Supply: Divertible Water at River Headings: includes • release from Project Storage, • return flows, and • any useable inflows to the Rio Grande
IN D2 is an Efficiency Relationship • IN: Release from Reservoir Storage • OUT: Delivery at River Headings or Project Supply • Efficiency: OUT / IN • If it really were a pipe Efficiency would be 100% Out
IN Actual Project (River) Efficiency • In good years, drain flows come back in to the River, and thus water is recycled. • Full Supply Year Efficiency: 120%
Actual Project (River) Efficiency • In bad years, drain flows dry up, and water is lost to the River conveyance losses. • Bad Supply Year Efficiency: 80 - 90% IN Losses
D2 Curve with All Data Through 1992:Reflects Historical Operating Efficiency
In Recent Years? • BOR has said that Project still operates at close to D2 efficiency, except for during the recent drought
How are we using D2 in our Regulations? • Junior groundwater will be curtailed, if necessary, to ensure that the Rio Grande Project can operate at the level of efficiency described by D2 • Under Depletion Limit Administration this curtailment would be either • Temporary, for critical years, or • Long term if necessary
Why Administer to the Historical Operating Condition? • Gives us a quantified target for surface water delivery • Documented in US BOR Rio Grande Project Water Supply Allocation Procedures • It has been the basis of Rio Grande Project operations for 50 years • It is generally favorable to New Mexico
Priority Administration Will Not Be Easy or Pleasant • Seniors get a full supply before juniors get any • When determining who gets curtailed: only seniority counts • although the State Engineer will not curtail essential domestic uses • Groundwater rights are generally junior • The burden imposed by shortages is not shared
The State Engineer Prefers Alternative Administration • Local water users agree on a workable alternative solution • For example • Shortage sharing • Reserve pools of water in reservoir storage to ensure Project deliveries • Other options
Agri- culture Industries Municipalities Your Comments & Ideas