Making New Places From Old Spaces The Waikanae WTP And RRwGW Upgrade

In May 2015 Kapiti Coast District Council (KCDC) completed the first stage of the Kapiti Water Supply Project (KWSP) to ensure that the water demands of the Waikanae, Paraparaumu, and Raumati (WPR) communities are met for the next fifty years. A new resource consent has enabled water to be taken from the Waikanae River during lower river flows than previously permitted. This is achieved by offsetting the water abstracted from the river with a direct and equal discharge to the river of ground water abstracted from the Waikanae borefield. This concept is known as the River Recharge with Groundwater (RRwGW) scheme. 

As part of achieving the scheme objectives the existing WTP required renewing and upgrading. To do this a number of old spaces within the forty year old plant were engineered into places providing modern water treatment operations. To create the innovative RRwGW scheme, design and construction works were undertaken to convert and expand the existing groundwater supply and to normalise the groundwater through land contact before it enters the Waikanae River surface water. 

This significant project to the Kapiti Coast community was implemented between June 2012, when detailed design commenced, and June 2015, when construction was completed. This was done successfully despite the challenges of doing so on a fully operational plant and the need to operate the supply from the groundwater source throughout the two summers that fell within the construction period.