Reduced water production at two treatment plants is expected to affect seven water companies following below-average rainfall in the Ndakaini Dam catchment. Nairobi City Water and Sewerage Company says reduction at Ndakaini Dam is expected to trigger longer water rationing periods for customers served by seven water companies /AI GENERATEDResidents of Nairobi and surrounding counties have been advised to use water sparingly in light of extended rationing occasioned by a 35 per.