WATER SENSITIVE DESIGN PROJECT

Download the Peel-Harvey Water Sensitive Design Locall Planning Policy and Technical Guidelines:

P-H Model WSUD LPP

P-H WSUD Tech Guidelines

Note large file size ~ 10Mb. This document is licensed to, and distributed by, the PHCC under a Creative Commons Attribution 2.5 Australia License

Segments of the Peel-Harvey System suffer from ongoing threats due to eutrophication, principally caused by excessive loads of phosphorus entering this coastal waterway. Traditional approaches to stormwater management have focused on the construction of drainage systems with the purpose of efficiently delivering runoff from developed areas into receiving waters. However this runoff is now recognised as a major source of nutrients, sediments and litter.

The coastal plain catchment of the Peel-Harvey System is the focus of significant urban expansion and rural residential development, where there is considerable risk of traditional forms of development leading to a net increase in phosphorus loads entering the Peel-Harvey System. The Peel-Harvey Water Sensitive Design Project, managed by the Peel Development Commission, is concerned with minimising phosphorus contaminated stormwater runoff from all forms of non-agricultural development.

The project aimed to establish a consistent approach to development in the Peel-Harvey System to minimise the discharge of phosphorus-contaminated runoff. This was intended to be achieved through the establishment of water sensitive design (WSD) principles, performance standards and land-use planning prescriptions to ensure phosphorus export rates from new development and subdivision is minimised and maintained to meet water quality targets set under the Water Quality Improvement Plan (in development) and Environmental Protection Policy (1992) for the Peel-Harvey System.

The objectives of WSD in the Peel-Harvey catchment are to ensure phosphorus export rates from land subject to development (including subdivision) will achieve and maintain the water quality objectives of the Peel-Harvey System through:

avoiding inappropriate development,
promoting patterns of land-use and land treatment consistent with the protection of the environmental values of receiving aquatic environments;
infiltration of stormwater to underground aquifers;
specially designed landscaping for removing phosphorus from runoff; and
protection and enhancement of wetlands and stream corridors for phosphorus attenuation and environmental flows.

To achieve the above, the Peel Development Commission (with the assistance of the Coastal Catchment Initiative team, local governments in the region and the Peel-Harvey Catchment Council) have developed two essential tools; a draft Peel-Harvey Local Planning Policy for Water Sensitive Urban Design and Water Sensitive Urban Design Technical Guidelines for the P-H Coastal Catchment. Combined these documents provide the both the planning framework and the technical assistance required for the implementation of Water Sensitive Design in the Peel-Harvey Catchment and provide the environmental management criteria and standards to prevent impacts on the natural water cycle, avoid increased demand on existing downstream drainage infrastructure, promote more efficient use of water, intercept, detain and remove phosphorus prior to discharge to receiving waters and control soil erosion during and after the construction phase.

Local Planning Policy for Water Urban Sensitive Design

The Model Peel-Harvey Local Planning Policy (LPP) encourages the application of the following Water Sensitive Urban Design (WSUD) principles when undertaking strategic and statutory planning within the coastal plain catchment of the Peel Inlet and Harvey Estuary:

Provide protection to life and property from flooding that would occur in a 100 year Average Recurrence interval (ARI) flood event;
Retain and restore existing elements of the natural drainage system, including waterway, wetland and groundwater features and processes, and integrate these elements into the urban landscape, possibly through the use of multiple use corridors;
Minimise pollutant discharge through implementation of appropriate non-structural source controls (such as town planning controls, strategic planning and institutional controls, pollution prevention procedures, education and participation programs and regulatory controls) and structural controls. The aim being to reduce pollutant export via runoff and leaching from urban development;
Manage rainfall events to minimise runoff as high in the catchment as possible. Use multiple low cost ‘in-system’ management measures to reduce runoff volumes and peak flows (e.g. maximise infiltration from leaky pipes, soakwells and stormwater pits installed above pollutant retentive soil media);
Maximise water efficiency, reduce potable water demand and maximise the reuse of water harvested from impermeable surfaces.

The LPP developed is a model local planning policy to assist Local Government to determine strategic and statutory proposals within the EPP Policy Area of the Peel-Harvey Coastal Catchment and is available to the local governments to adapt, adopt and implement to suit their local needs.

Peel-Harvey Technical Guidelines for Water Sensitive Urban Design

The Peel-Harvey Technical Guidelines for WSUD (in prep) have been developed to support implementation of the (draft) Peel-Harvey Water Sensitive Urban Design Local Planning Policy and the objectives of the Peel-Harvey Water Quality Improvement Plan (in prep).

These Technical Guidelines are not intended to be an exhaustive catalogue of WSUD elements, but rather have been prepared to provide local government, developers and consultants with an insight into the importance of site characteristics with respect to the selection of individual WSUD elements in the ‘build-up’ and design of appropriate combinations of structural and non-structural practices or treatment trains.

The document provides guidance on the application of WSUD for the soil-hydrological conditions prominent throughout the Peel-Harvey region and have been prepared to complement Chapter 9 (Structural Controls) of the - Stormwater Management Manual for Western Australia (DoE, 2005).

The document:

provides information for Residential, Industrial and Special Rural development in the Peel-Harvey catchment
will help to identify constraints and opportunities that may apply at any given site;
provides guidance for the design of WSD treatment trains, including structural and non-structural components;
recommends management responsibilities and maintenance regimes; and
provides the technical basis for implementation of the (draft) Water Sensitive Design Local Planning Policy and for appraising the conformity of development proposals with that policy

The Peel-Harvey Water Sensitive Design Project has been continued through funding National Heritage Trust and National Action plan for Salinity and Water Quality, joint initiatives of the Australian and Western Australian Governments, administered by the South West Catchments Council through the South West Regional Investment Plan 2006/08. The expanded project is working closely with the local governments of the catchment to facilitate the implementation of the Local Planning Policy and Technical Guidelines and to develop appropriate strategies for the retrofitting of existing stormwater systems to achieve similar objectives.

For more information please contact the Peel-Harvey Catchment Council on (08) 9550 4225 or via info@peel-harvey.org.au.