CHENNAI: The Municipal Administration and Water Supply (MAWS) Department has issued guidelines to coordinate the activities of various agencies involved in rain water harvesting (RWH) to maximise benefits and foster teamwork.
Along with the Jal Jeevan Mission, the Managing Director of Tamil Nadu Water Supply and Drainage Board has emphasised implementation of RWH and issued guidelines for construction, rejuvenation and maintenance of RWH structures for sustainable water management, and implementation across the state.
The MAWS department will act as a nodal department for coordinating RWH activities of various government departments and agencies. State-level coordination committee under the chairmanship of the Chief Secretary to Government, and district level coordination committees under the chairmanship of the District Collectors, have been constituted for guiding, monitoring, reviewing and coordinating the implementation of RWH.
Speaking about the implementation, an MAWS department official told DT Next, “While RWH was already emphasised, the government has now published standard design models, which specify exact internal layouts and recharge shaft specifications, preventing non-standard constructions previously built due to a lack of awareness. Instructions have been issued to district collectors and municipal commissioners to encourage adoption across urban areas to maximise long-term groundwater recharge.”
Following this, Chief Minister C Joseph Vijay’s State-wide awareness campaign was launched on October 21. To make RWH a mass movement, TN is focusing on building new structures and rejuvenating existing ones. An expert committee comprising officials from CMWSSB, TWAD Board, and the Directorate of Municipal Administration has structured technical proposals for implementation.
RWH applies to houses, apartments, industries, parks, and public spaces. Direct collection uses sumps or tanks, while groundwater recharge techniques vary by soil type. For desilted open wells and abandoned borewells, collect filtered rooftop run-off. In sandy and red soil areas, use percolation pits, shallow recharge wells (1 metre wide, 3-5 metres deep), filter strips, and permeable pavers. For clay soil, require percolation pits with bores or 1m-wide, 1.5 metre-deep recharge trenches fitted with 150 mm bores to bypass low permeability.
An official in CMWSSB said, “The survey results of 2023 showed that out of 10 lakh buildings, 8 lakh have RWH structures. The board have been approaching, educating and conducting practical sessions in the high-rise buildings in added areas of GCC, where RWH are mandated while constructing. We conduct weekend inspections, public awareness drives, and system checks across all zones.”
For government institutions, the guidelines stated to appoint officers to supervise the de-clogging of existing RWH setups, identify sites for new structures, allocate budgets, and conduct periodic reviews. Incorporate RWH into routine campus management and run awareness drives using digital and non-digital channels at district and state levels. Cover capital and maintenance costs using Urban Local Body (ULB) funds, CSR contributions, government grants, or institutional funds.
For private premises, identify residential buildings, apartments, gated communities, commercial complexes, hotels, industries, private schools, and hospitals that require new RWH installations or rejuvenation of existing structures. Encourage RWAs and property owners to formulate and implement RWH improvement plans.
Enforce compliance with Building Rules and relevant GOs governing mandatory RWH installations across all private premises.