Predicting inter-season price jumps in the market for temporary water allocations

Summary The market for temporary water allocations in the Northern Victoria Regulated river system has matured to the point where new instruments to manage risk can be of benefit to water users. One of these instruments could be a series of option contracts issued by the Water Authority. However a serious impediment to the introduction of options is the variation in prices across seasons. Prices jump between the end of one season and the beginning of the next mean that appropriate option strike prices cannot be determined until a period of trading in the new season allows price discovery to take place. This prevents an options market being available at the beginning of the season when it is most useful to irrigators. In this paper we look at winter rainfall for the town of Jamieson, upstream of Lake Eildon and the volume of water in Lake Eildon as predictors of the price of temporary water allocations at the beginning of the irrigation season. We develop a climate driven regression model which allows us to link the inter-seasonal jumps with the biophysical parameters of the system. By better understanding the factors dictating the size of the price jumps between seasons options can be developed that are not restricted to the current season. We also consider the implications of the infrastructure upgrades currently underway and recent policy changes on the market for temporary water allocations. The carryover policy which allows water to be kept for use in subsequent seasons, and the reserve policy, which is designed to allow the delivery of initial allocations and water carried over at the start of the irrigation season each year, are two recent policy innovations. These policies should smooth prices and reduce the jump in prices that have been seen between irrigation seasons.