2.1.5 Key typologies of cloudburst network blue-green streets and open spaces

SPONGE COLLABORATIVE + WEAVING WITH WATER Team

MULLASSERY CANAL FRAMEWORK AND CANAL EDGE MASTERPLAN

limited capacity within the existing storm water drains, landscape strategies to ‘hold and delay ’ the water are strategically planned along the adjoining open spaces and street buffers.

There are three key components to a Sponge Framework: streets, open spaces, and buildings. The Sponge Landscape Infrastructure toolkit deals with a set of interventions that can be applied to: (1) Sponge Streets, (2) Sponge Open Spaces, and (3) Sponge Buildings.

Figure 26 - Details of Sponge Streets, Sponge Open Spaces, and Sponge Buildings (Image Credit: Sponge Collaborative)

2.1.5 Key typologies of cloudburst network blue-green streets and open spaces:

The building blocks of the Sponge Framework consist of a hierarchy of classifications that can be applied to buildings, all the open spaces and roads within the precinct area. More information is required in the form of GIS data to understand specific site topography in more detail for final recommendations. Typologies for the Sponge Framework open spaces, buildings and streets are highlighted below:

SPONGE COLLABORATIVE + WEAVING WITH WATER Team

MULLASSERY CANAL FRAMEWORK AND CANAL EDGE MASTERPLAN

Figure 27 - Diagram illustrating typical sections of Sponge framework streets and components (Image Credit: Sponge Collaborative)

1. Sponge Buildings: Rainwater harvesting strategies such as green roofs and detention tanks on public and private property, catch the first glimpse of runoffs, directing it to local sponge spaces or storage tanks that can be recycled for use as grey water. This can be a region wide policy to be implemented on both private and public property. 2. Sponge Collector Street: Designated for street widths varying between 4-5m. This involves redesigning the profiles of some streets in order to convey water more quickly in case of an extreme rainfall event. This is a useful template in the case of a narrow right-of-way which has limited capacity for installation of a high-capacity stormwater drains or retention beds, which is common across many parts of the precinct, particularly in the Karikkamuri neighbourhood. 3. Sponge Green Streets: This typology has been applied on streets with a right of way varying between 6 to 7m with potential for footpaths wide enough to create rain gardens and bioretention planters on sidewalks and curb bulb outs, resulting in less pressure on the stormwater drains, and a greater possibility for retention. 4. Central Sponge Spaces: This typology has been applied to large open spaces of width greater than 25m like playgrounds and plazas, that are adjacent to the canal and sponge green streets in the framework plan.

Their function is to temporarily hold water from the larger catchment areas and then safely convey it to the storm water pipes with maximum delay. 5. Local Sponge Spaces- Local sponge spaces of width less than 25m are localised water holding landscapes like the rain garden and strips of parks, that can temporarily hold water before conveying to central sponge spaces and stormwater pipes. 6. Cloudburst+Sponge streets- These are large arterial roads of width between 10-11m with large strips of retention beds like rain gardens inserted along the medians and sidewalks that hold and delay water during normal rainfall. They are then connected to storm water pipes for conveying the overflow in case of exceedance rainfall events.