The BC Ministry of Environment retained Associated Environmental to develop a preliminary water budget for the Similkameen Aquifer to support groundwater allocation decisions under the new Water Sustainability Act. Given the high reliance on groundwater in the Similkameen valley for irrigation and municipal waterworks, an understanding of the current effects of water extraction was needed. To address this need, the project team developed a water budget model for the aquifer. The water budget operated on a monthly time-step and considered both surface water and groundwater components, as well as seasonal (i.e., irrigation) and continuous (i.e., domestic) water use.
As part of the project, we developed a user-friendly Microsoft Excel spreadsheet model to allow decision-makers to assess the influence of changes in water demand and climate variability on groundwater levels within the Similkameen Aquifer, and on Similkameen River streamflows at the downstream extent of the aquifer. Inputs to the water budget model are editable by the user to allow Ministry staff to update water demand estimates as groundwater wells are licensed.