Stormwater quality objectives

The State Environment Protection Policies (SEPPs) require stormwater quality treatment to be undertaken. The SEPPs are binding for all government agencies, private individuals and businesses conducting activities on private and public land.

​Clause 44 of SEPP Victoria

If water run-off from the land surface is causing or is likely to cause non-compliance, control measures must applied. This may include eliminating or treating sources of contaminated run-off and changing land use or land management practices.

EPA Victoria has more information on SEPP Victoria and its relationship to Clause 56:

Minimum requirements

To meet minimum SEPP requirements, developments should meet the Best Practice Environmental Management Guidelines for Urban Stormwater, available from CSIRO Publishing.

The following describes the base level of treatment during the construction and post-construction phases.

Construction phase

Pollutant type​ Receiving water objective​ Current best practice performance objective​

Suspended solids​

Comply with SEPP​

Effective treatment of 90% of daily run-off events (e.g. <4 months ARI). Effective treatment equates to a 50 percentile suspended solids concentration of 50 mg/L.

 

This can be achieved by installing a sediment ponds to remove 95% of sediment down to 125 µm for a 1 year ARI.​

Litter​

Comply with SEPP​

Prevent litter from entering the stormwater system. This requirement extends until 95% of the lots are constructed or a period of two years has passed.​

Other pollutants​

Comply with SEPP​

Limit the application, generation and migration of toxic substances to the maximum extent practicable.​

Post-construction phase

Pollutant type​ Receiving water objective​ Current best practice performance objective​

Suspended solids (SS)​

Comply with SEPP (not to exceed the 90th percentile of 80 mg/L) (1)​

80% retention of the typical urban annual load​

Total phosphorus (TP)​

Comply with SEPP (base flow concentration not to exceed 0.08 mg/L) (2)

45% retention of the typical urban annual load​

Total nitrogen (TN)​

Comply with SEPP (base flow concentration not to exceed 0.9 mg/L) (2)

45% retention of the typical urban annual load​

Litter​

Comply with SEPP (No litter in waterways) (1)

70% reduction of typical urban annual load (3)​

Flows​

Maintain flows at pre-urbanisation levels​

Maintain discharges for the 1.5 year ARI at pre-development levels​

  1. An example using SEPP (Waters of Victoria, 1988), general surface waters segment
  2. SEPP Schedule F7 - Yarra Catchment - urban waterways for the Yarra River main stream
  3. litter is defined as anthropogenic material larger than five millimetres
Last updated:
6 November 2017