Tackling the Issues with Rainwater Harvesting

• Context (DTE): Despite mandating rainwater harvesting (RWH) in all three mega-cities (Delhi, Bengaluru, Chennai) implementation struggles persist. This has led these cities towards Day Zero.

Measures taken to Install rainwater harvesting systems in the three mega-cities

• Bengaluru has mandated rainwater harvesting in residential colonies since 2010.
  • In 2021, the Bangalore Water Supply and Sewerage Board (BWSSB) made it mandatory for buildings on sites measuring 60×40 feet and more.
• Chennai Metropolitan Development Authority (CMDA) mandated rainwater harvesting system designs in building plans since 2002.
• Delhi Jal Board (DJB) enforced RWH systems since 2012, with penalties for non-compliance and financial incentives for adhering to regulations.
  • DJB offers financial assistance up to Rs 50,000 and a 10% water bill rebate for residents with adequacy certificates for their rainwater harvesting systems.

Challenges in implementing rainwater harvesting systems

• Communities are losing interest due to a lack of space and high installation costs.
• Weak enforcement and insufficient monitoring.
• Inadequate awareness and support for maintenance.
• Insufficient measures to prevent sewage contamination.

What needs to be done?

• Focus on community-level rainwater harvesting due to limited land availability for household RWH.
• Provide technical assistance and raise awareness about rainwater harvesting.
• Rejuvenating traditional rain harvesting structures like lakes, ponds, and temple tanks.
• Stringent guidelines for rainwater harvesting installation and maintenance, including piezometers for groundwater monitoring (National Green Tribunal Committee).
• City water authorities should conduct regular monitoring of structures and their impact.
• Implement both incentives and penalties to encourage communities to build effective RWH systems.

Sponge Cities The term “sponge cities” is used to describe urban areas with abundant natural areas, such as trees, lakes, parks, or other good designs intended to absorb rain and prevent flooding. How can cities become ‘sponge cities’? Using permeable asphalt or concrete for parking lots and vegetated green roofs for rooftops. Streets could be redesigned to direct stormwater to parks and recreational fields. Natural areas could be used for stormwater storage, improving their ecological value. Adding more green spaces.