Evaluating Water Transfers in Irrigation Districts
Abstract
The participation of irrigation districts (IDs) in surface water transfers from agriculture-to-municipal uses is studied by examining IDs’ economic and political behavior, comparing their performance with non-districts (non-IDs), and analyzing the role of economic and demographic heterogeneities in water transfers. Economic modeling, econometric, and analytical techniques are used to investigate these issues.
An economic model is developed to investigate how the collective-type institutional structure of IDs in the presence of local interdependencies (between internal water delivery and external water transfers) and increasing returns to scale in the internal water delivery causes reduction in marginal benefit of water transfers and the optimal transfers. The model is also used to investigate how the involvement of the U.S. Bureau of Reclamation in IDs causes more water uses in agriculture availing less for external transfers. The conjunction of multiple uses and exclusion rights without ownership rights in IDs’ water and vote-maximizing political structure of IDs are found to create disincentive for water conservation and transfers.
Water transfer responses of IDs and non-IDs are empirically investigated by using a Quasi Maximum Likelihood Estimation (QMLE) technique. Based on the analysis of 38 years of time series water transfer data, IDs are found to be less responsive in water transfers relative to non-IDs in terms of water right-weighted transfers. It is found that water scarcity, private housing permits, and nonfarm establishments are positively associated with water transfers. The marginal effect of water scarcity on water transfer is stronger for non-IDs than for IDs.
Impacts of economic and demographic heterogeneities on water transfer behavior of IDs are investigated using unbalanced panel data econometric techniques. Water right holdings and population in nearby cities of IDs are found to be significantly correlated with water transfer behaviors of IDs. Larger IDs with higher water right holdings and higher population centers in nearby cities are found to be more responsive to water transfers.
The findings complement previous studies that commend public attention for policy redesign including institutional changes to motivate IDs to increase their water transfer activity.
Description
Keywords
Irrigation Districts, Water Transfer, Economic Model, QMLE, unbalanced panel data