Leak Detection and Repair to Improve Network Performance in Fez, Morocco
In the city of Fez, the water distribution rate of performance is 30 percent lower than what the Moroccan National Plan envisages for 2020. Actual losses occur when water is lost through cracks and leaks in the distribution system. The reduction of physical losses through regular maintenance and reconstruction can delay or eliminate the need to invest in new sources of water. These activities also reduce operating costs by reducing the frequency of breaks and faults in the distribution network. In Fez, the rate of performance is around 52 percent (i.e. 48 percent of water is lost)—quite far from the expected rate. In 2002, RADEEF admitted that the need to detect and repair leaks was very important. Despite topography constraints, the rate of network performance could grow substantially if serious network upgrade measures are implemented, as demonstrated by the current case study.
Morocco has good control over its water resources and consumption. However, the water sector faces serious constraints and challenges due to its climatic and hydrological context and the growth of urban and tourist populations. Groundwater reserves are overexploited, causing deterioration in the quality of water by seawater intrusion. Thus, efforts are required to preserve and manage available water resources in a rational and sustainable manner. In Fez, and in other cases, the water distribution performance rate is severely affected by water losses due to cracks and leaks in the distribution system. The topography of the city causes excessive pressures that need to be kept within limits. At the same time, the water distribution network needs to be upgraded.
Conflicts arising from the baseline situation
No immediate conflicts are apparent, but growing demand and limited supply eventually creates water shortage.
Description of the applied measure, its introduction and operation
The Fez water network has been deemed weak, with a 53-percent rate of performance. RADEEF has established an action plan based on four measures:
1. Network regulation
Pressure reducers were installed to regulate the network. When pressure exceeds 10 bars, it is reduced to a maximum value of 6 bars. RADEEF acquired pressure modulator devices that further reduce base pressure downstream from stabilisers during low-consumption times (i.e. night time).
2. Network modelling
The first step of this action was to develop a numerical model of the major water network (reservoirs, equipment, pipe with a diameter of DN ≥100 mm), while taking also into consideration topological data (altitude Z, characteristics of works and sections) and consumption data. In addition, a campaign to measure flow and pressure was carried out for each zone of influence over a 24-hour period. Once a calibrated model was obtained, a dynamic analysis was performed over 24 hours to highlight irregularities in the distribution network, such as: excessive and low pressures at off-peak time, excessive speed on segments etc.
3. Study of performance improvement and definition of rehabilitation works
The study for the definition of rehabilitation works was based on the identification of sectors with the highest leakage, as well as the location of leaks (at connections or in pipes). All statistical data available to the operating department (all leaks detected on the network, both by the repair maintenance and preventive maintenance crews) were used jointly with the existing segmentation.
4. Network rehabilitation works
Network rehabilitation was carried out (100-km pipeline and 25,000 connections), especially in areas with an old system and/or where night flows were significant.
Physical and ecological impacts of the measure
The action plan implemented by RADEEF resulted in improved network performance (from 53.31 percent in 2003 to 63.28 percent in 2011). (See figure)
The higher rate of performance led to some improved results for drinking water activity due to reduced purchases. In addition to the significant reduction of pressure in the area, this action has allowed for lower operating costs and significant flow gain.
The annual savings of water in cubic metres are summarised here.
Financial and other impacts of the measure on different stakeholders
The accumulated generated gain was evaluated in 2011 at around 258 million Moroccan dirham (MAD). Details of gains are summarised in the following table: (see table)
The accumulated gain is roughly EUR 25 million, which exceeds the initial investment of EUR 10 million. Even after accounting for interest, the NRW reduction measure seems to be economically attractive.
Resilience of the achievements, sustainability of the results
An investment in building operator skills is required to sustain the obtained result. The National Office for Electricity and Drinking Water (ONEE Water Branch), through the International Institute for Water and Sanitation (IEA), meets all the requirements to achieve this aim. Concerning information management, efforts will be undertaken to implement geographic information management systems introducing real-time management components.
- Network performance increased from 53.3 percent in 2003 to 63.2 percent in 2011.
- Financial aid from AFD
- Engineering expertise study from 2006 (SEM)
- RADEEF skills and own funds
- Network performance
- Non-revenue water
- RADEEF obtained a loan of EUR 10 million to finance the rehabilitation works (100-km pipeline and 25,000 connections). The financial value of saved water accumulated to about EUR 25 million in 10 years.
Mr. Khaled Nadifi
- ONEE Water Branch, “Outline report on leak research”
- Veolia Environment, “Technical report on drinking water”, 2011
- ONEE Water Branch, “Manual of leak research”, 2009 version
- RADEEF, “Action plan for improving the efficiency of the distribution network”, November 2012, MP3: “Connection policy at ONEP”
- RADEEF website: www.radeef.ma