Water Sensitive SA

Interactive Map

Henley Annexe, Park Lane
Henley Beach

Henley Annex (Park Lane, off Cudmore Terrace, Henley Beach). This is a small sub-division constructed in 1999, in the City of Charles Sturt, comprising 13 medium-density residences located in a parcel of land whose level is below that of the nearest stormwater trunk main, some 150 m away. Conventional practice in such situations calls for the use of a sump to collect the runoff in storm events and a pump to convey it to the local stormwater main. The principle of onsite stormwater retention was employed to collect runoff from the development and to direct it to two “dry” zones (basin and swale) located at the downstream extremity of the development. Each zone receives half of the runoff: One has a gravel-filled sub-structure, the other is founded on “Atlantis” (milk crate) cells. Each facility stores water, temporarily, on the surface to a depth of 0.30 m while seepage takes place into the porous sub-structure. The basin and swale system have overflow spillways matched to the local street drainage capacity (ARI, Y = 10 years event); overflow in these circumstances – and in greater events – passes to the local stormwater trunk main. The system is located in a region of sandy clay: Emptying time for the basin and swale is less than one hour.

The scheme presents an opportunity to reuse the stormwater runoff for irrigation or non-potable use (e.g. toilet flushing). Characteristics of the site and stormwater management scheme include :

  • the catchment is approximately 1 ha
  • infiltration basin area: 300 square meters (0.5 m thick, 20 mm single size gravel)
  • 62 m long grassed swale with infiltration capacity and storage of 100 cubic meters (50 cubic meters below surface Atlantis cells)
  • excessive runoff in large storm events bypasses via overflow sumps and overland flow path to the street drainage system
  • the system is designed to retain all stormwater produced in the catchment up to the 1 years flood, representing over 90% of the runoff generated on the residential development.

Images: Baden Myers


Contact us to provide any new information or images for existing WSUD projects.

Update WSUD project