SPONGE COLLABORATIVE +
WEAVING WITH WATER Team
MULLASSERY CANAL FRAMEWORK AND CANAL EDGE MASTERPLAN
1.2 Constraints and Opportunities - Precinct Level The city’s aging stormwater infrastructure and concretised canals are not designed to handle extreme events. The change in Kochi’s land cover leads the gray infrastructure network to often fail under moderate rainfall during the monsoons. Kochi’s stormwater capacity was designed for a landscape that has changed dramatically as green cover was replaced by built-up area and tree canopy within urban areas decreased. Simultaneously with an increase in likelihood of flooding due to extreme rainfall events, there is the potential for an increase in drought-incidence due to irregular rainfall and insufficient groundwater infiltration, which points to the likelihood of permanent changes in the hydrological cycle.
Precinct Level Challenges: (Based on the limited data available and Site analysis) 1.
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Increased flooding: The increase in impervious ground cover due to development generates more runoff after rainfall events. This generates peak runoff with very little lag time and overwhelms the stormwater system and canals. In traditional stormwater management, this runoff is quickly conveyed towards the backwaters or sea. The rush to flush away water increases flood risk while stressing the canals and reducing the potential for aquifer recharge. Increased water contamination: Lapses in solid waste management and unregulated sewage outfalls into waterways contaminate surface and subsurface water systems. Periyar and Muvattupuzha rivers as well as the aquifer are the main sources of drinking water that are threatened by the waste loop. Collection of solid waste debris and silt also compromises the efficacy of the stormwater system. Increased aquifer depletion: Over-extraction of groundwater along with zero groundwater infiltration, results in depleting the groundwater levels. This induces saltwater intrusion along the coast and seeps deeper into the region. This renders most of the present groundwater wells redundant and can induce drinking water scarcity during years of weak monsoon or extended droughts. Increased coastal erosion: Ernakulam and Kollam districts are placed second in position for coastal erosion among other coasts of Kerala. Climate change will increase the intensity of storm surges that further wash away coastal soil. Due to climate change and frequent storm surges most of the soil gets eroded. The construction of seawalls hastens coastal erosion as they amplify wave dynamics towards unwalled edges and prevent sediments from aggregating on coastlines. Unsafe streets for women: Although there are many institutions in the precinct, the streets are poorly lit and lack visibility from the community. Students and women feel unsafe using the streets at night, which further result in them dissociating from the city’s public space. The empty streets and open spaces also reduce the footfall for local businesses in the area. Inaccessible footpaths: Broken and fragmented footpaths make the streets a nightmare for vulnerable groups, including women, the disabled, and children. The dense network of streets in the city have been taken over by private motor vehicles and parking, leading to traffic congestion and an 8% increase in road deaths from 2018 to 2019. According to the Evangelical Social Action Forum’s study on Walkability and Pedestrian Facilities in Kochi, 2016-2017, 60% of the respondents expressed fear while crossing roads. Poor solid waste management:The city’s waste management system has not yet tackled residential, commercial, and medical waste despite the presence of organisations like Kudumbashree and Haritha Karma Sena. Solid waste is dumped into the canal, clogging the waterways or dumped on the streets, making it unattractive.