Our Experience in Reducing Water Losses by Regulating Pressure in Water Supply Systems November 2011, Dubai, UAE Prof. Dr. Dipl.-Eng. Gancho Dimitrov Head of Department: Water Supply, Sewage and Purification of Water at at the University of Architecture, Civil Engineering and Geodesy, Sofia, Bulgaria

Pressure Reduction In our experience pressure control in water supply networks is an effective measure for : the reduction of water loss and water consumption the reduction of the accident rate abolition of restrictions on traffic in the streets the reduction of operating costs the substantial reduction in investment the removal of less amounts of water from the water sources providing the necessary ecological balance of ecosystems

Types of pressure control, and our research results By maintaining constant pressure after the control valve By maintaining constant pressure after the control valve through water consumption or for specific periods of time; Maintaining a minimum pressure through the critical point of the water supply network. individual zones in 45 residences, 120 control valves reduction of water losses from 15% to 50% of the average water consumption success in reducing accidents by 50% to 90%

Case Studies: Pressure Management DMA 1, 2009 Total length of water network: m House connections:1 327 Number of people: Maximum pressure: 9.1 bar Pressure regulator: DN 300 Output pressure: 5 bar

Fig.1 Change in water consumption at the beginning of the zone Results a) period from January 2007 before installing the pressure valve; b) period from June after adjusting pressure.

DMA 2, 2007 Total length of water network: m House connections: Number of people: Pressure regulator: DN 600 Outlet pressure by night: 3,5 bar Outlet pressure by day: 5,0 bar Case Studies: Pressure Management

Results Fig. 2 Change in water consumption at the beginning of the zone for the period from August 2007 Fig. 3 Change in water pressure at the beginning of the zone for the period from August 2007

Results Fig. 4 shaft with valves and pressure reducing valve with a diameter of DN 600 with two operation modes (with 5 bar pressure and 3,5 bar) Effect: Reduction: Water losses by 20% Number of accidents by 75% Investment recovery period – 1 year

DMA 3, 2010 Total length of water mains: m Number of people: Pressure regulators: DN 600 and DN 400 Input pressure: 4,7 bar Output pressure: 3,7 bar Case Studies: Pressure Management

Results Fig. 5 Installation - Main control valve with DN600 with a bypass line Effects Reduction: Water loss reduction 1,2 mln m3/ per year Number of accidents by 50% Investment recovery period - 1 year

CONCLUSIONS Pressure control is a relatively efficient way to reduce water losses and especially the number of accidents. Investment recovery period for pressure regulating is very short (from a few months to 1 year). Reduction of water losses by pressure control has a multiplier effect. It reduces operational costs and investments for new pipelines, pumping stations, treatment plants, and natural wastewater.

for questions and contact: Prof. Dr. Dipl.-Eng. Gantcho Dimitrov Mobile: Web: Thank you for your attention!