Economic Demand Irrigation Calculator

The Economic Demand Irrigation Calculator (the Tool) is a spreadsheet designed for economic practitioners who need to obtain an equation for aggregate demand for irrigation water under conditions of limited time and/or financial resources. The Tool finds a middle ground between the approaches that require large amounts of data and approaches that have restrictive assumptions. Optimization routines and whole-farm modeling are examples of the first approach, and fitting an assumed constant ?elasticity demand curve to a single data point is an example of the last.

The Tool is intended for estimating demand for irrigation water on an irrigation-season basis, but short-term in the sense that technology, management skill, infrastructure and acreage base are assumed to be fixed. Its results should be considered most reliable with small departures from base conditions.

Required input data for the Tool include crop prices, yields, evapotranspiration and irrigation requirements. This information is typically available from local producers or crop advisors.

For a single crop, the Tool produces a demand curve and equation. For multiple crops, it produces a graphic and tabular summary of aggregate demand by horizontal summation, and provides the ability to manually adjust parameters of two different approximation equations. The user`s guide and report provide guidance for adapting the results to larger analyses or in response to potential limitations of the Tool's design.

Background/Problem Statement: Water in the western United States is essentially fully allocated. Thus water for new demands must come from reallocation of existing supplies. Since over 80% of the water withdrawals in the west are for agriculture, potential reallocation mechanisms and the economic impact of reallocation require knowledge of the economic demand for irrigation water is also needed to evaluate:

1) Water-use impacts of shifts in evapotranspiration and precipitation resulting from climate change

2) Water supply engineering projects such as building new storage or constructing aquifer storage and recovery (ASR) infrastructure

3) Water management options such as:

a) Water marketing

b) Groundwater banking

c) Buyout of irrigation water rights

d) Pricing mechanisms designed to encourage conservation

4) Water use impact of the current unprecedented increase in agricultural commodity prices

You must agree to the U of Idaho EULA ( http://www.uihome.uidaho.edu/default.aspx?pid=114352 ) in order to download or use the product.