Rainwater Harvesting System at Umaid Heritage Housing Complex

Location: Jodhpur, Rajasthan
Scale: zonal level
Implementing organisation:Housing complex authority with architect Anu Mridul
Average annual rainfall: 320 mm

Total volume of rainwater harvested: Approx 21.1 million litres
Area: 110 acres
Operational since: 2008
Capital cost: 80 million
O&M: Rs 12,000

The Umaid Heritage residential complex in Rajasthan is a private township located southeast of Umaid Bhawan. The site is located in the city of Jodhpur where the traditional watermanagement system is getting gradually destroyed due to modernisation and urbanisation. The water table at the site is still quite low in the range of 20-40 metres below ground level (mbgl).

Henceforth, the “Birkha Bawari” is designed as a monumental RWH structure at Umaid Heritage, which is based on the concept of “Kunds” and “Baoli”, which were the traditional practices of RWH in Rajasthan and Gujarat. The Bawari structure acts as a recreational space for inhabitants as well as storage structure of rainwater

TECHNOLOGY & DESIGN

Catchment area The entire area of the site acts as catchment area for the system to catch water. The rainwater is collected from the open areas through the natural slopes as well as from the roof top of houses which in turn are connected with natural slope of the site through drainage conduits. The nature of the catchment area is rocky with high runoff coefficient. The entry of rainwater is blocked from the inlet wall for first two flushes of rainfall to avoid debris and dust particles going to Bawari.

Conveyance system
The housing complex is designed in two phases, one with apartments called phase-II and the other with plotted housing called phase-I. The rainwater is collected from rooftops and road channels through storm water drains; open channels and slots. The runoff from phase-II is collected from the storm drains and connected to the drains in phase-I sloping towards the RWH structure – Birkha Bawari, located in Phase I of the complex.

Sedimentation and storage tanks
The Birkha Bawari consists of longitudinal open rainwater storage structures. The system consists of series of constructed tanks making it a linear 135 meter long structure. The water enters from both the sides of underground longitudinal storage structure (Bawari), which holds 17.5 million liters of harvested rainwater annually and serve as a rich source of water for landscaping water requirements of green area in an otherwise water scarce region. Rainwater comes from either side of the structure (Bawari) and first enters into the hidden settlement tank from there, water flows to the series of tank with deepest depth of 18 meter below the ground level

BENEFITS

The RWH system captures around 21.1 million liters of rainwater reducing the dependence on municipal water supply or ground water extraction. The average cost of water tanker (10,000 liters per tanker) in Jodhpur is Rs. 800 – 10,000/-, thus by using the rainwater as alternate source of water about Rs. 2.36 million are saved annually. The rainwater harvesting system at the township collects 30 per cent of the potential rainwater on the site to maintain the green area in the complex by meeting its horticulture water requirements. Furthermore, the Bawari structure acts as a recreational space for inhabitants as well as storage of rainwater.

The housing has a great property value as it demonstrates perfect combination of good architectural design and well maintained green spaces in a scanty rainfall site. In addition to the above the RWH structure helps in awareness creation on the overall concept of rainwater harvesting. The project site is frequently visited by universities/schools students and researchers.

Anu Mridul
Principal Architect
71 Nehru Park, Jodhpur - 342 003
Email: a.mridul.architect@gmail.com