A PRACTICAL APPROACH TO MONITORING WATER LEVELS IN PRAIRIE WETLANDS

Water-level monitoring was initiated on several wetland complexes on the Canadian Prairies in the early 1960s. Many of these wetland complexes are still actively being monitored using a method that obtains point measurements of water depth that can be used to determine water-level changes over time. This paper describes the depth-gauging method used in obtaining long-term water-level data for wetlands on the Canadian Prairies. This method has proven to be very reliable provided that observers are diligent about following procedural guidelines. Point measurements of relative depth resulted in stage values within 25 mm of those measured using conventional level surveys. In wetlands where more than one monitoring marker is deployed to monitor the range of water levels, a conversion factor is often used to determine maximum depth. The accuracy in determining maximum depth with a conversion factor is considered to be within 50 mm. Experience has demonstrated that the reliability of this method is dependent on the consistency of data collection, vigilance in the field, and careful screening of the data. Maintaining horizontal position of the measurement location is important, as the lowest point in the wetland is used as a relative datum. Vertical movements of the monitoring marker can also result in errors in the data if not identified and corrected accordingly.