Since the methods currently in place to track water use in the City of Novi are not based on the same methods we are invoiced by the Great Lakes Water Authority (aka Detroit Water & Sewerage Department), the Water & Sewer Division is in the process of implementing new technology to more accurately represent water use on a monthly basis. This involves the installation of a fixed network meter reading system to allow automatic reads, avoiding the need to manually collect readings in the future.
Water purchased figures are developed directly from the Great Lakes Water Authority (GLWA) invoices sent monthly to the City of Novi. Using the GLWA Wholesale Automated Meter Reading (WAMR) Portal, the volume of water purchased per the invoice is checked for accuracy by comparing to the five master meters supplying water to the City of Novi. This figure has historically been accurate with the exception of metering errors, which are noted both on the WAMR and the invoice.
Water sold is simply a figure based on the meter readings completed by the Water & Sewer Division. The figure does not take into account any water used via fire hydrant set-ups or water used in the operations and maintenance of the City of Novi DPS, whether by our designated contractors or City personnel. The accuracy of the water sold figures is currently compromised by the quarterly reading of water meters. A remedy to enhance the accuracy of tracking water sold would be to read all water meters, including hydrant set-ups, on a monthly basis to cross reference the data with GLWA’s monthly invoice. The fixed network system referenced above would provide the ability to read the meters monthly.
Water loss can be very difficult to accurately track. Many unknown variables effect the estimated quantity recorded in a water loss report. It is not standard practice to estimate the quantity of water loss through water main breaks, valve leaks, fire hydrant flow tests, hydrant flushing, and other sources. Although accurate hydrant use estimates can be calculated based on the flow and pressure, infrastructure leaks have an unknown variable of how long the water has been leaking.
Water loss tracking can be improved by switching to monthly water meter reading, which will be possible with the implementation of the fixed network meter reading system. Figures can be analyzed and tracked on a monthly basis as opposed to waiting for complete data at the end of the year.