Monitoring water consumption in office buildings
Why monitor your water consumption? Saving water and associated costs begins with an accurate assessment of current consumption. Knowing how much water you use, as well as when and why you are using it, is the first essential step to saving this precious resource.
How can you monitor water use in your office? Start with understanding what is driving your water consumption and how much you are paying for fresh water and sewage. Your bookkeeper or office/building manager should be able to provide all relevant bills and meter readings. Water utility companies also have these records on file. In addition to total water usage, try to get records on water usage for specific departments and activities (e.g. toilets, manufacturing process).
Besides examining water bills, there are other methods for collecting information on water use:
- Bucket and stopwatch approach: By timing how long it takes to fill a bucket (or vessel with a known volume), a flow rate (litres/minute) can be calculated, which can be used to determine water use based on the duration and frequency of each use event.
- Manufacturer and model data: Manufacturers can be contacted directly or search the Internet for information on equipment specifications to determine water use per event.
- Non-invasive ultrasonic flow meters: These can be fitted outside water pipes to track the flow-through rate and determine a water-use profile in target areas or processes.
- Shutdown check: By recording the water meter reading when everyone has left the building and again immediately before work resumes, you can establish how much water is still being used when the site is unoccupied.
Ideally, the data you gather should be stored or recorded electronically in a spreadsheet, for example, which enables you to filter and plot your data on graphs and develop more insight into what is happening. Resource Efficient Scotland has developed three measuring/monitoring tracker spreadsheets (see sources), which you can download for free to record and analyse resource use data in this way.
Benchmarking can be used to compare your water use with other similar companies/offices. The key benefits of benchmarking are that you can be sure that improvement targets are based on what has been achieved in practice. Water benchmarks for offices and hotels in comparative sectors are available from the Construction Industry Research and Information Association (see CIRIA source).
Having collected and analysed your data, you will be able to prepare a list of actions to address any opportunities that have been identified. Explore factsheets that describe measures and technologies that you can implement to save water costs in your office.