Honourable Kevin J. MacAdam, Minister of Fisheries and Environment, today reported on the results of a monitoring study conducted this past summer into the effects of high capacity irrigation wells on other wells, and the availability of groundwater resources in general. For many years, the Department of Fisheries and Environment has had a comprehensive procedure in place for the assessment and approval of high capacity wells, but the study was prompted by the increased number of irrigation wells constructed over the past few years and the public concerns raised about their impact.
Minister MacAdam reported that, "based on research conducted in the Baltic Area, irrigation activity was found to have virtually no impact on the overall availability of groundwater in the watershed at the level of pumping experienced this summer. Results also indicated that measurable changes to the water table as a result of pumping were restricted to an area of a few hundred metres from irrigation wells."
It is also estimated that the total volume of water extracted by all irrigation wells in the watershed would be equivalent to a little more than 1% of the annual amount of recharge to the groundwater in this area. This level of groundwater withdrawal is considerably lower than that seen in many Island watersheds supporting municipal or industrial use of groundwater over many decades. The report also notes that the observed impact of irrigation wells compares closely with the impacts that are predicted during the initial assessment and approval of these wells.
The impact of irrigation wells is examined from two perspectives in the report, the changes to the elevation of the water table in the vicinity of irrigation wells and in the watershed as a whole, and by making a comparison of the actual volume of water used by irrigation wells to the overall availability of groundwater in the study area. The Baltic area was chosen for the study because of the high density of irrigation wells in a relatively small area. Information was collected through the construction of additional observation wells, the installation of continuous water level recorders, and the reporting of actual water use by operators of the irrigation systems.
Mr. MacAdam is very positive about the results from the study. "This study not only supports the current procedures used for assessing and approving high capacity wells, but also confirms the fact that the use of these wells, when properly managed, pose no threat to our groundwater resources."