2.1.7 Scenarios

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MULLASSERY CANAL FRAMEWORK AND CANAL EDGE MASTERPLAN

designed to temporarily hold and delay the rain water. These are then safely conveyed to existing/proposed storm water drains thus reducing the run-off volume and increasing the lag time. Also during storm events accompanied by high tides, when the eciency of existing drain is highly reduced, these inserted blue green infrastructure play an important role in assisting the existing storm water channels to mitigate flood and reduce property damage.

2.1.7 Scenarios: How the Blue Green Infrastructure in integration to Grey infrastructure plays out during different rain events throughout the year:

Figure 30 - Diagram illustrating the role of components of Sponge Framework during various stages of Cloudburst events (Image Credit: Sponge Collaborative)

Average Rainfall Event with runoff matching designed gray infrastructure capacities (~10% of Annual Rainfall Volume)

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MULLASSERY CANAL FRAMEWORK AND CANAL EDGE MASTERPLAN

Figure 31 - Diagram illustrating the components of Sponge Framework activated during average rainfall event(~10% annual rainfall volume) (Image Credit: Sponge Collaborative)

SPONGE COLLABORATIVE + WEAVING WITH WATER Team

MULLASSERY CANAL FRAMEWORK AND CANAL EDGE MASTERPLAN

Figure 32 - Section across AK Seshadri road illustrating how the components of Sponge Framework perform during 10% increase in Annual rainfall volume (Image Credit: Sponge Collaborative)

Average Rainfall Scenario (10% Annual Volume):

During the regular rainfall event, on-site mitigation through rainwater harvesting and Sponge retention streets are designed to capture the run-off and hold and delay water to avoid water clogging on adjacent streets.

Exceedance Rainfall Event with runoff exceeding designed gray infrastructure capacities (~20% of Annual Rainfall Volume)

Figure 33 -Diagram illustrating the components of Sponge Framework activated during exceedance rainfall event(~20% annual rainfall volume) (Image Credit: Sponge Collaborative)

SPONGE COLLABORATIVE + WEAVING WITH WATER Team

MULLASSERY CANAL FRAMEWORK AND CANAL EDGE MASTERPLAN

Figure 34 - Section across AK Seshadri road illustrating how the components of Sponge Framework perform during 20% increase in Annual rainfall volume (Exceedance event) (Image Credit: Sponge Collaborative)

Exceedance Rainfall Scenario (1-year storm or 20% Annual Volume):

During the 20% rainfall event, in addition to on-site mitigation through rainwater harvesting and Sponge retention streets, local retention areas like parklets are designed to capture the run-off and infiltrate the pollutants from streets and sites before conveying it safely into the canal/stormwater pipe.

SPONGE COLLABORATIVE + WEAVING WITH WATER Team

MULLASSERY CANAL FRAMEWORK AND CANAL EDGE MASTERPLAN

Figure 35 -Diagram illustrating the components of Sponge Framework activated during extreme cloudburst event(~70% annual rainfall volume) (Image Credit: Sponge Collaborative)