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connecting communities to water


linda norman & benny Larsen of ach consulting for the nz stormwater conference 2017

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The loss of small streams and lack of open green spaces are the result of urban sprawl and traditional development. Many developers view stormwater treatment and mitigation as an onerous requirement that adds cost but not value. The result is that the stormwater management methods often lack connection to the surrounding environment and fail to connect communities to water. Synergizing with developers, architects and landscape architects during the early stages of development facilitates the design of stormwater treatment and mitigation with the potential to enhance amenity value. The resulting creation of green space in an urban environment can increase property values and liveability.

This paper presents 4 different developments which seek to achieve stormwater management which creates amenity, drawing upon some new technologies adapted to New Zealand’s unique environment.

The first development was a retirement village where the traffic loading was expected to be low. The local territorial authority requirements included treatment and mitigation for the 1% AEP rainfall event to the equivalent of grass runoff. The objective was met by providing stormwater flow-through planters incorporated into the overall landscape design. The flow-through planters employ a river stone surface which behaves as a rocky-river bed removing suspended solids and providing visual balance.

The second project required flood protection and pre-treatment for a highly urbanised commercial environment. The design provides detention storage for the 1% AEP rainfall event and pre-treatment in a device analogous to a rocky-river valley.

The third development used a banded wetland to replace a pond design which was initially consented by the territorial authority. The wetland was designed to allow community interaction with the habitat.

The fourth project takes a fresh approach to vegetated swales as a community amenity. The vegetated swale design involved tying it to the native landscape, providing low maintenance and longevity. 

Click here to download the full paper.