Rainwater Harvesting – An Option to Reduce Demand on Water Supply Shane Phillips

Akaroa relies on the town water supply for their potable water. During peak demand, as well as times of drought, water restrictions are imposed on the community. One option to help ease this problem is rainwater harvesting. Rainwater harvesting is a method of collecting rainwater, from rooftops, to alleviate these pressures on potable water supplies. For our final year project for Natural Resources Engineering at the University of Canterbury we have investigated the use of rainwater harvesting within the Akaroa Township. During peak holiday times, the population of Akaroa can swell to more than twice its original size, putting pressure on local amenities, in particular the already restricted domestic water supply. The current water management practices imposed during water restriction times have a significant impact in conserving water and reducing demand. Imposing Level 1 restrictions, i.e. alternate day watering, can reduce demand by around 17%, whilst imposing Level 4 restrictions, i.e. a total hosing ban, can deliver around a 52 % reduction in water demand (Shorrock, 2008). Rainwater harvesting may provide a major part of the solution to water problems in Akaroa. The idea for this project was borne out of discussions with Katie Shorrock, MWH, durin