Andres Roa – Director, AR & Associates Ltd, Auckland
Rowan Carter – Consultant – Green Infrastructure / Associate, AR & Associates Ltd, Auckland
Andres Roa and Rowan Carter delivered a joint presentation at Water New Zealand’s 2105 Asia Pacific Stormwater Conference in May this year. The conference paper entitled “KIRIMOKO PARK DEVELOPMENT, WANAKA – A LIVING EXAMPLE OF INTEGRATED WSUD” was written in partnership with Jan Heijs of Heijs Consulting Ltd and showcases one of AR & Associates Water Sensitive Urban Design (WSUD) projects.
The paper details the development principles and design elements applied to Kirimoko Park, compares conventional versus WSUD design outcomes and discusses WSUD vs conventional design capital construction costs plus some of the key building blocks/stumbling blocks that may influence the implementation of WSUD.
Kirimoko Park is an innovative 117-lot green-field residential subdivision that exemplifies effective integration of landscape architecture and urban design with stormwater management function.
The design of stormwater management systems within Kirimoko Park is based on a Water Sensitive Urban Design (“WSUD”) philosophy. The protection of the receiving environment is achieved through the acknowledgement, preservation and use of the inherent natural landform and hydrology, and the integration of stormwater design with landscape and urban architecture elements.
One of the key objectives of the adopted WSUD philosophy is to mimic natural rainfall-runoff behaviour and maximise the use of ‘surface’ stormwater features such as swales, raingardens and basins, in favour of traditional underground piped infrastructure. This approach showcases the value and beauty of stormwater when used as a resource, through the visible integration of water features within open spaces. This has resulted in superior landscape architecture, urban design and public amenity, which in turn has translated to a market-edge outcome for the developer with completed lots becoming highly desired by prospective purchasers.
Piped systems provide an ongoing asset management liability with regard to operation, maintenance and renewal. They are also difficult to access, prone to blockage and structural failure and there is an ongoing risk of these underground systems receiving wastewater cross connections. These risks are eliminated with an above ground stormwater solution.
In addition to the environmental, landscape architecture, urban design and public amenity benefits offered, experience within Kirimoko Park has shown that the use of WSUD also results in a more cost effective stormwater management solution when compared to piped infrastructure. This all translates to higher cost-benefit and superior economic outcomes for the project.
The paper will discuss the design process, the implementation and lessons learned as well as customer feedback from the developer and the first inhabitants.