Value of Irrigation Water for Crop Production in the South Saskatchewan River Basin

Abstract

Abstract:In this study, value of water used for irrigation was estimated in the South Saskatchewan River Basin using the concept of producer surplus. The basin was divided into sub-basins for the provinces of Saskatchewan and Alberta. Although the water in these sub-basins is supplied by the South Saskatchewan River, its value is highly variable across sub-basins, partly due to differences in cropping practices, climate, soil type, and level of water applied to the crops. Taking a long-run accounting perspective (all resources paid for), value of irrigation water in crop production in Alberta ranged from $16.95 per dam 3 in the Alberta portion of the SSRB to $24.90 per dam 3 in the Oldman River sub-basin. In Saskatchewan, this value was $9.58 per dam 3 in the southwest Saskatchewan region and $61.74 per dam 3 in the Lake Diefenbaker Development Area (LDDA). Higher value in LDDA, relative to Alberta sub-basins, is explained, in part, by differences in irrigated crops mix between the two regions. One of the major limitations of this study is that value of water could not be estimated for individual crops, in part due to lack of data on water use levels.Resumé : Dans la présente étude, la valeur de l' eau servant à l'irrigation a été estimée pour le bassin de la rivière Saskatchewan Sud selon le concept du surplus des producteurs. Le bassin a été divisé en sous-bassins pour les provinces de la Saskatchewan et de l'Alberta. Bien que l' eau dans ces sous-bassins provienne de la rivière Saskatchewan Sud, sa valeur varie énormément d'un sous-bassin à un autre, en partie à cause des différences dans les pratiques culturales, le climat, le type de sol et le niveau d' eau appliqué aux cultures. Partant d'une perspective comptable à long terme (toutes les ressources étant payées), la valeur de l' eau d'irrigation dans les cultures agricoles en Alberta allait de 16,95 $ par dam3 dans la portion de l'Alberta du bassin de la rivière Saskatchewan Sud à 24,90 $ par dam3 dans le sous-bassin de la rivière Oldman. En Saskatchewan, cette valeur s' élevait à 9,58 $ par dam3 dans la région sud-ouest de la Saskatchewan et à 61,74 $ par dam3 dans la région du lac Diefenbaker (Lake Diefenbaker Development Area). La valeur plus élevée dans cette région, comparativement à celle des sous-bassins de l'Alberta, s' explique en partie par les différences dans le mélange des cultures irriguées entre les deux régions. L'une des limitations majeures de cette étude tient au fait que la valeur de l' eau ne pouvait être estimée pour les cultures individuelles, en partie à cause du manque de données sur les niveaux d'utilisation de l' eau. 258Canadian Water Resources Journal/Revue canadienne des ressources hydriques

Assessing the Economic Implications of Reduced Water Availability and Better Management Practices on Representative Farms in Southern Alberta

“…We assume that crop yield is a quadratic relationship of the ratio of actual to potential water use for a given year (Heikkila et al ; Samarawickrema and Kulshreshtha ). In addition, crop yield is a function of the maximum potential yield of a given crop in a given irrigation district.…”

“…The maximum potential yield ( ymax jr ) is determined from the following expression where Z j , B 0 j , B 1 j , and B 2 j are crop specific parameters (Table ). The level of potential evapotranspiration by crop and irrigation region is obtained from Samarawickrema and Kulshreshtha () and reported in Table . These values are used to impute the value of ymax jr , which also are reported in Table .…”

“…Sources: Potential evapotranspiration by crop and irrigation region: Samarawickrema and Kulshreshtha (). Maximum yield: authors’ calculation.…”

“…A growing body of literature has developed to evaluate alternative scenarios of reduced water availability and increasing the per unit productivity of water in irrigated agriculture (cf. Carey and Zilberman ; Zwart and Bastiaanssen ; Ali et al ; Evans and Sadler ; Efetha et al ; Geerts and Raes ; Samarawickrema and Kulshreshtha ; He and Horbulyk ; Schaible et al ; Bennett and Harms ; He et al ; Klein et al ; Schaible and Aillery ; Ali and Klein ). Ali and Klein () build on the optimization framework in He and Horbulyk () and He et al () at the basin level to assess the economic effects of current water allocation policies at the district level.…”

“…Klein et al () estimate water use technical and economic efficiency for 13 irrigation districts and underscore the need to increase water use efficiency given future water demands that will come from industrial use. Samarawickrema and Kulshreshtha () and Bennett and Harms () estimate the crop yield and evapotranspiration relationships for irrigated crops in Southern Alberta for use in impact assessments of water allocation scenarios (see also Zwart and Bastiaanssen ; Trout and Bausch ). This study is similar in spirit to that of Ali and Klein () but differs in the modeling approach developed, the counterfactual scenarios considered, and the level of analysis from which to investigate the effects of reduced water scenarios (farm level vs. basin level)…”