rainwater harvesting in chandigarh_architect surinder bahga_august 19, 2015

RAIN WATER HARVESTING SYSTEM

Ar SURINDER BAHGASAAKAAR FOUNDATIONChandigarh

Water, simply put, makes the existence of the human race on this planet possible.

With few exceptions, water has always been a natural resource that people take for granted.

WATER AND HUMAN EXISTENCE

The World Bank reports that, 80 Countries now have water shortages and 2 billion people lack access to clean water.

In the last century, the human population has increased from 1.7 billion to 6.6 billion people, and total amount of portable water decreased.

The UNEP* also reports that 1.2 billion people are being affected by polluted water, and that dirty water contributes to 15 million child deaths every year.

*UNEP- UNITED NATION ENVIRONMENTAL PROGRAMME

IS THE AVAILABILITY OF WATER ADEQUATE?

WE NEED TO SAVE WATER FOR

HUMANITY

STRATEGIES OF WATER CONSERVATION Any beneficial reduction in water loss, use and waste of resources.

Avoiding any damage to water quality.

Improving Water Management Practices that reduce or enhance the beneficial use of water.

WATER MANAGEMENT PRACTICES

REUSE of gray water. RECYCLING of wastewater through purification at a

water treatment plant. RAINWATER HARVESTING

RAINWATER HARVESTING

Rainwater harvesting is a technique used for collecting, storing, and using rainwater for landscape irrigation and other uses.

The rainwater is collected from various hard surfaces such as roof tops and/or other types of manmade above ground hard surfaces.

HISTORIC PERSPECTIVE

The concept of rainwater harvesting began around the 300BC, when the farming communities in Balochistan (now located in Pakistan, Afghanistan and Iran), and Kutch, India, used rainwater harvesting for irrigation.

Rainwater harvesting was done in the Indian states of Madhya Pradesh, Maharashtra, and Rajasthan in the olden days.

Ratanpur, in the state of Chhattisgarh, had around 150 ponds.

PRACTICE IN INDIASTEP WELLS The builders dug deep trenches into the earth for

dependable, year-round groundwater. They created stairs leading down to the water. Step wells also served a leisure purpose, as well as providing

water. Step wells also served as a place for social gatherings and

religious ceremonies.

Adalaj Wav Step Well Drawing

Chand Baori in Abhaneri, Rajasthan

Stepped Well, Hampi, Karnataka

Agrasen Ki Baoli, New Delhi

Rani ki Vav, Patan, Gujarat

Rani ki Vav, Patan, Gujarat

Richard Cox is a senior lecturer at Cardiff School of Art and Design UK, studied 300 step-wells of India in 20 years .

RICHARD COX – A RESEARCHER OF STEPWELLS

RAJENDRA SINGH -CHOSEN FOR 2015 STOCKHOLM AWARD FOR WATER CONSERVATION

In about 20 years since Singh has begun working, 8,600 rain water storage tanks and other structures to collect water have been built.

Water had been brought back to around 1,000 villages across the state, the organisation claimed.

RAINWATER HARVESTING SYSTEM -CHENNAI

Chennai government made the installation of RWHS compulsory as per the by-laws.

Chennai saw a 50% rise in water level in 5 years and improve water quality also.

PRACTICES AROUND THE WORLD

MEXICO

Lomnitz is the director of Isla Urbana, explains that, rainwater harvesting is a natural fit in Mexico City, since over a million homes already have tanks, or cisterns, for storing water from either the intermittent city water system or delivery trucks.

People don't have to buy a cistern because these are already part of their houses. Therefore, the system is quick and easy to install.

The roofs are tilted and diverted towards a 1,000 cubic metre basement tank from where the water is used for toilet flushing and cooling the building

JAPAN

From 1985, the country constructed six million jars to harvest the rain for drinking purpose.

In a year, there are 150 days during which water from jar has to be used.

Thai Jar

THAILAND

ISRAEL

• The first rainwater catchment system was installed at an elementary school in Lod, Israel.

• RWHS are being installed in local schools for the purpose of educating school children since then.

• Roof collection system – 8500 litre reservoir: 10 toilets (1/2 of school bathrooms).

NEED OF RWHS IN CHANDIGARH• Chandigarh is a fast growing city.• Growth Rate has increased by 28% in the past decade • Estimated by 2025, the water demand will be 800 MLD

that is about 58% higher over the 2011 demand of 494.25 MLD.

Ground water level has declined swiftly in last decade. The data collected by the CGW, Chandigarh shows a gradual

decrease in the total decreased Ground Water Resources (3.636%)

*CGW – CENTRALGROUND WATER BOARD

* ham = Hectare metre

STATUS OF GROUND WATER LEVEL

DECLINE GRAPH

The rainwater harvesting potential of Chandigarh is 50%, of the average water storage

Annual rainfall is 1061 millimetres.

Therefore, storing and recharging rainwater will go a long way in contributing towards sustainability of water supply.

BENEFITS CHANDIGARH CAN GAIN THROUGH RWHS

HOW TO CONSTRUCT A RWHS

RECHARGE PIT LAYOUT

RWH THORUGH STORM WATER Rainwater harvesting potential:

Rooftop- 80%Roads- 50%Green areas- 20%

The drainage wells or traps for storm water must be covered to ensure less pollution in the water.

DETAIL OF ROAD SIDE STROM WATER TRAP

RWH ON CITY LEVEL

Initial Plan of Chandigarh by Albert Mayer Included Two Leisure Valleys

LEISURE VALLEY

LEISURE VALLEY

Later on Le Corbusier Built One Leisure Valley

Now as Chandigarh has developed on its periphery, two more leisure valleys can be constructed to reserve more water through CHECK DAM.

CHECK – DAM SYSTEM

A CONCEPTUAL SKETCH GIVEN BY RAJENDRA SINGH ON VISIT IN CHANDIGARH

• RWH system should be improved by Check –Dam system.

• He advised to provide Reservoir in each sector which store water hence adequate storage for people .

DETAIL B

DETAIL:

The New Lake at Sector 42, Chandigarh Spread over three acres, is fed by two tube wells.Instead if the rain water of the surrounding sectors can be trapped and supplied to it, a lot of ground water can be saved.

SECTOR - 42 LAKE VIEW

EACH SECTOR DESIGNThe Periphery of a typical sector measures 1200 m x 800 m. Storm water drains run on either three or all four sides of the sector.

Recharge structures can be built at intervals of 50 m.

STORM WATER TRAPS AT PERIPHERIAL ROADS

LAYOUT OF SECTOR 20

RWH ON BUILDING LEVEL

COMMERCIAL AREAS

• Also rooftops of the commercial areas may harvest a good amount of water.

• Large spaces are designed in commercial areas used for Parking.

• If covered with PERVIOUS CEMENT CONCRETE they can absorb a large amount of water

RESIDENTIAL AREAS

RWH ON BUILDING LEVEL

Processes of rain water harvesting:• Cascade capture• Ground water recharge shaft• Recharge through soak pit/hand pump/ bore well/ settlement tank• Recharge through trench• Roof water harvesting

RECHARGE THROUGH SOAK PIT/HAND PUMP/ BORE WELL/ SETTLEMENT TANK

SETTLEMENT TANK

SETTLEMENT TANK

ROOF WATER HARVESTING

Making Terrace Garden Supporting roof structure Waterproof and root repellent membrane(s) Insulation

TYPICAL ROOF SECTION FOR HARVESTING

PROJECTS BY:

SITE PLAN OF BUILDING – DESIGN OF RWH SYSTEM

SBI BANK, SECTOR - 17, CHANDIGARH

DETAIL OF RECHARGE WELL

MARRIED ACCOMODATION, JAIPUR, RAJASTHAN

RAIN WATER HARVESTING LAYOUT OF THE HOUSING

DETAIL OF RECHARGE WELL

Malkiet Singh House, Chandigarh

Vipin Pubby House, Chandigarh

Red Cross, Chandigarh

CONCLUSION

With the decreasing availability of water, RAIN WATER HARVESTING is one of the best options of conserving water.

RHW should be made mandatory through Bye-laws by Government.

This Recyclable process sustained the Bio-diversity hence makes us SMART and GREEN

THANK YOU