The "Holland Marsh Drainage Scheme, located in the Town of Bradford (Ontario), Township of King and the Township of West Gwillimbury" is dependent on two pump installations to maintain lowered Holland River levels in the cultivated Holland Marsh polder area. Each location pumps water from that section of the River located within the Marsh, over the earthen dyke surrounding the Marsh into "The Canal". The Canal rejoins the Holland River at Bradford, and flows on to combine with the East Branch Holland River. The pumping locations are identified as the Springdale Pumping Station and the Bradford Pumping Station (Drawing 1). For the purposes of this report, water is pumped from the River up into the Canal. This report summarizes the results of a series of pumping rate calibrations performed on the three (3) pumps at the Springdale Pumping Station and the two (2) pumps at the Bradford Pumping Station. The purpose of this study was to provide a simple means of recording pump output on a continuous basis. These data could then be used in generating a detailed account of the water volumes being pumped out of the Marsh area with time. Chemical analyses of these waters, along with the pumped volumes, could then be used to calculate a drainage water materials budget. The study provided a secondary benefit in that the calibration test allowed a comparison of the present pump output and efficiency with that in the original pump design. Two (2) of the five (5) pumps were found to be signficantly below original design output and efficiency. Both these pumps were inspected and replaced resulting in a significant increase in output and efficiency.