What is the Drainage Nutrient Intervention Program?
The Drainage Nutrient Intervention Program (DNIP) trials on ground works to remove nutrients from drains and tributaries in the Swan Canning Catchment.
These include:
- drain restoration
- re-establishment of tributary vegetation
- wetland creation
- use of nutrient retentive materials
The program aims to reduce nutrients and other pollutants in stormwater being discharged into the Swan and Canning rivers. DNIP is one of eight programs in the Trust’s Healthy Rivers Action Plan.
Drainage Nutrient Intervention Program projects include:
- Liege Street Demonstration Wetland
- Bickley Road Basin Restoration
- Manley Street Basin Bio-retention System
- Wharf Street Wetland and Civic Parkland
- Ellen Brook, Brand Highway Nutrient Filter
There are plans for further projects at nutrient-rich urban drainage sites in the Canning Plain, South and Central Belmont catchments and the rural Ellen Brook Catchment. DNIP also involves:
- trialling new nutrient intervention technologies
- monitoring and evaluating drainage restoration works
The DNIP complements other Healthy Rivers programs, the Swan Canning Water Quality Improvement Plan and the work of community and catchment groups which focus on more long-term solutions for the control of nutrients and pollutants at their source in the catchment.
How are DNIP project sites selected?
DNIP projects target key areas.
Urban projects
Wharf Street and Liege Street main drains, discharging into the Canning River upstream from Kent Street Weir. This section of the Canning River is at high risk of algal blooms in summer and autumn. - Planned works in the Mills Street main drain, discharging into the Wilson Wetland in the Canning River Regional Park, also upstream of Kent Street Weir.
- Planned works in the South and Central Belmont catchments. The South Belmont main drain catchment is a priority urban catchment because of its high contribution of nutrients to the upper Swan River. The Central Belmont catchment has provided opportunities to implement nutrient interventions in a space-constrained, highly-urbanised area discharging into the Swan River.
Rural projects
- Ellen Brook, targeted because of its high contribution of phosphorus to the Swan River. At 715 square km it is the largest sub-catchment in the Swan Canning Catchment. Its annual contribution to the Swan River includes around:
- 7% of the total flow
- 37% of the total phosphorus
- 10% of the total nitrogen
DNIP Partners
The Trust implements DNIP projects in cooperation with stakeholders and through partnerships with:
- local government
- natural resource management groups
- community groups
- Water Corporation
- Department of Water
- land owners
- Indigenous groups
- other stakeholders
DNIP has supported restoration projects initiated by catchment or natural resource management groups in other parts of the Swan Canning Catchment, to improve water quality in drains or tributaries.
How does drainage work in Perth?
Stormwater Management Manual
The Trust worked with the Department of Water to develop a Stormwater Management Manual for Western Australia. The manual provides high-level policies, planning principles, and practical onground best practice advice in stormwater management. Chapters of the manual can be downloaded from the
Department of Water website (external website).
Contact us
If you would like further information about the Drainage Nutrient Intervention Program (DNIP) or other stormwater management issues
contact the Trust.
Project information pages