In their ongoing effort to unravel how to manage and reduce Non-Revenue Water (NRW), the partners of the Nakuru-Kisumu WaterWorX Water Operators' Partnership (WOP) shared their experience in NRW reduction on a webinar hosted by the WaterWorX NRW Community of Practice.
The WOP partners explained the scope and impact of their intervention in 7 District Metered Areas (DMAs) with a relatively large NRW volume (potential Return on Investment) covering 3,100 service connections. The WOP between VEI and three Nakuru County water service providers (NAIVAWASCO, NARUWASCO and NAWASSCO) managed to reduce NRW by 32.000 m3/month within a 12-month period (from project design to implementation).
• Nakuru Urban (4): Eastmore, Mawanga, St. Mary, Natewa
• Nakuru Rural (1): Chepseon
• Naivasha (2): CBD, Lakeview
Efforts were made to hydraulically isolate the DMAs and obtain a stable water balance. The partners conducted Minimum Night Flows (MNF) measurements to establish the physical/commercial losses volume ratio (predominantly physical losses for most DMAs) as a basis for prioritizing the most cost-effective interventions.
Based on this established ratio, physical (water) loss reduction measures included the realignment or replacement of poorly designed, sub-standard quality, and dilapidated distribution and ‘spaghetti lines’ (customer service connections). In the NAWASSCO DMAs, 1,820 consumer connections and service lines were mapped in the GIS.
Commercial loss reduction measures focused on the testing (600+) and replacement (175+) of hundreds of aged, damaged, and buried water meters, repositioning of 365 vertically installed meters for accurate flow (consumption) measurement (see pictures below), disconnection of and/or formalization in the billing system of illegal connections and new accounts.
Reduced water losses ranged from 20-50% and increased sales from 12% to 72% in the individual DMAs. For example, water saved in the village of Chepseon (one of the DMAs) is currently providing water to hundreds of new consumers in the DMA as well as downstream users on the feeding distribution line where a Water for Life project was implemented. This also allowed to increase supply hours from 12 hours/3 days per week to 12 hours/every day.
While the scale of the total intervention is relatively small (7 DMAs with 3,100 connections), the evaluated case revealed that the majority of investments were recovered through water savings and increased revenue within 1 to 3 years; the replacement of a more capital intensive 6’-4’-3’ distribution line in CBD DMA NAIVAWASCO being the only exception (13 years).
Where the WaterWorX WOP under Phase 1 covered the complete investment of the pilot project, a revolving fund for the WOP NRW activities has been introduced under the recently launched Phase 2 of the WaterWorX Programme. This will enable to gradually increase the utility contribution from 40% in Year 1, to 60% in Year 2 and 100% in Year 3. Generated returns from previous years will be reinvested in upscaling activities up to 2026.
