Everyone wants to reduce water loss. No one likes to see water running over the ground. But people who understand the water industry know that reducing water loss to zero just isn’t economical. Spending $10,000 to save $50 worth of water may not be good management. It depends on the value of water which is not necessarily the price customers pay for water.
Pretty much everyone who has worked in water distribution has been involved with hydrant flow testing at one time or another. It’s not very difficult. Place a pressure gauge on a residual hydrant and flow a nearby hydrant while recording the hydrant flow and the pressure at the residual hydrant with no flow and with flow. The procedure is documented in many places (AWWA, 2016).
Pump stations are fed by the power grid, so when the power goes out, it also goes out for water pumping stations. And water utilities don’t like their systems losing pressure.
The Blackwell Group is a multidisciplinary engineering firm located in Virginia that performs work in the residential, commercial, and government sectors. Stormwater design and site grading are just a few of the many services that Blackwell Group offers. In a typical stormwater project, the Blackwell Group designs a grading plan for a proposed redevelopment or new development. While creating the grading plan, they evaluate stormwater impacts of both pre- and post-development by performing hydrologic studies for the 2-, 10-, and 100-year storm events.
Pumps & Systems magazine had a good article recently on the need to calibrate pressure gauges. They pointed out that pressure gauges (and sensors) tend to lose accuracy over time; specifically, that gauges should be calibrated at a regular interval, suggesting annually as typical.
Pressure zones are important but can be difficult to understand. OpenFlow WaterGEMS and OpenFlows WaterCAD makes creating and managing pressure zones easy.
In the blog A Multi-Species Decay Model to Support Cost-Effective Chlorination in Distribution Systems, a cost-effective chlorination strategy is defined as the least-cost combination of doses (locations and rates) that achieves effective chlorination for a given stable flow regime and water temperature. Searching for such a strategy requires extended-period simulations for many dosing location and rate combinations.
Most hydraulic engineers would admit that the Darcy-Weisbach equation is the most theoretically correct equation for head loss in pipe flow. It is based on a force balance between the driving forces of pressure and gravity, offset by head loss and can be applied to any Newtonian fluid. It’s pretty elegant looking.
Pretty much all well-run water utilities periodically develop a master plan. The plan looks out 20, 30, 40 years and tries to layout development in source, treatment, and distribution systems. Based on the best available demand forecast, pipes, tanks, and pumps are laid out to evolve the system efficiently.