Domestic Wastewater Management Plan

What is a Domestic Wastewater Management Plan (DWMP)?
Council is required to develop a Domestic Wastewater Management Plan (DWMP) under State legislation to assist with the management of on-site disposal of effluent where land is not connected to a reticulated sewerage system.  A DWMP establishes preferred approaches to monitoring the condition and management of on-site effluent treatment systems, enforcement, and direction for planning decisions on land use and development.

Adopted DWMP
The Council adopted its most recent DWMP at the 24 August 2022 Council meeting.  The document comprises two parts:

The DWMP encompasses the whole municipality outside of the sewered areas of Colac, Apollo Bay, Marengo, Skenes Creek and Birregurra, but has a particular focus on settlements and rural areas within the declared drinking water catchments in the Otways.  Specific towns addressed by the Plan include: Forrest(PDF, 646KB) , Beech Forest(PDF, 663KB) , Lavers Hill(PDF, 550KB) , Gellibrand(PDF, 672KB) , Kawarren(PDF, 657KB) , Barwon Downs(PDF, 623KB) , Barongarook(PDF, 297KB) , Carlisle River(PDF, 606KB) , Alvie(PDF, 256KB) , Cororooke(PDF, 556KB) , Coragulac(PDF, 560KB) , Beeac(PDF, 625KB) , Kennet River(PDF, 231KB) , Separation Creek(PDF, 243KB) and the Barham River Catchment(PDF, 258KB) .

The Plan categorised all unsewered lots using the most reliable, up-to-date data available on matters such as climate, soil and topography, resulting is properties having a sensitivity rating (for the purpose of considering on-site effluent treatment) of ‘low’, ‘moderate’, ‘high’ or ‘very high’. These ratings provide clarity to property owners about the information they will have to supply with any future planning application, or where no planning permit is required for a development, for any application to Council’s Health Protection Unit for a “Permit to Use” an on-site effluent treatment system.  
What Information needs to be submitted with a development proposal?
The degree of information to be provided to Council varies according the property’s sensitivity risk rating.  For ‘Low’ rated properties, only very basic information would need to be submitted, compared to more comprehensive information for those rated ‘High’ or ‘Very High’
Below are links to the Information Checklists which relate to the different risk categories:

Land owners wishing to lodge a planning application for development which relies on an on-site effluent treatment system, or where no planning permit is required, when lodging an onsite wastewater management system application, land owners should contact Council’s Health protection Unit on (03) 5232 9400 to determine the risk rating of their land.
Once the sensitivity risk rating for a property is confirmed, information needs to be prepared in accordance with the relevant check list.  In the case of proposals where the risk is Moderate or higher, the information will need to be prepared as part of a Land Capability Assessment by a suitably qualified professional.
The Shire’s Health Protection Unit is happy to clarify these requirements at the number above.

The high rainfall settlements of Lavers Hill and Beech Forrest will provide challenging to treating and retaining effluent on a property.  The following are reference designs for Wick Trench effluent disposal design specific for these settlements for dwellings by number of bedrooms and soil type:

Beech-Forest_Wick_720_8mm(PDF, 99KB)Beech-Forest_Wick_720_10mm(PDF, 99KB)Beech-Forest_Wick_720_12mm(PDF, 99KB)Beech-Forest_Wick_720_20mm(PDF, 99KB), Beech-Forest_Wick_900_8mm(PDF, 96KB)Beech-Forest_Wick_900_10mm(PDF, 96KB), Beech-Forest_Wick_900_12mm(PDF, 96KB)Beech-Forest_Wick_900_20mm(PDF, 96KB)Beech-Forest_Wick_1080_8mm(PDF, 99KB)Beech-Forest_Wick_1080_10mm(PDF, 99KB)Beech-Forest_Wick_1080_12mm(PDF, 99KB)Beech-Forest_Wick_1080_20mm(PDF, 99KB).

Lavers-Hill_Wick_720_8mm(PDF, 100KB)Lavers-Hill_Wick_720_10mm(PDF, 100KB)Lavers-Hill_Wick_720_12mm(PDF, 100KB)Lavers-Hill_Wick_720_20mm(PDF, 100KB)Lavers-Hill_Wick_900_8mm(PDF, 97KB)Lavers-Hill_Wick_900_10mm(PDF, 97KB)Lavers-Hill_Wick_900_12mm(PDF, 97KB)Lavers-Hill_Wick_900_20mm(PDF, 97KB)Lavers-Hill_Wick_1080_8mm(PDF, 97KB)Lavers-Hill_Wick_1080_10mm(PDF, 97KB)Lavers-Hill_Wick_1080_12mm(PDF, 97KB)Lavers-Hill_Wick_1080_20mm(PDF, 97KB).

Wick Trench Construction Sheet(PDF, 242KB)

Wick Trench Design Sheet(PDF, 111KB)


Direction for planning decisions
One of the key outcomes of the DWMP is that is provides direction to Council and the water corporations (Wannon Water and Barwon Water), responsible for managing the drinking water catchments in the Shire, in decision making on planning permit applications for use and development in the Otways.

State Government “Guidelines for Planning Permits in Declared Open Potable Water Catchments” (2012) state that dwellings should not be approved in drinking water catchments at a density greater than one per 40 hectares.  This presents challenges for land owners seeking to develop their land in locations where this density is exceeded, particularly in towns such as Gellibrand, Beech Forest and Lavers Hill.  This Guideline can be varied if a Domestic Wastewater Management Plan is prepared and supported by the water corporations. 
Now that Council has adopted the 2015 Plan, with support from Barwon Water and Wannon Water, planning permit applications for dwellings in the declared water catchments can be considered on their merits.