An INNOVATIVE WAY TO DESIGN ROOF AND HARVEST RAINWATER

1. PROPOSED “RWH” RETROFITTING FOR
MY HOUSE
SOUKTIK BHATTACHERJEE
001710201010

2. INTRODUCTION
• LOCATION
43/B KOPALITALA LANE , KOLKATA -700032 , WEST BENGAL , INDIA
OPPOSITE OF HARE STREET POLICE STATION
• RESIDENTIAL ATTACHED HOUSE
• AREA OF ROOF – 240 SQ.M
• AREA OF COURTYARD – 60 SQ.M
• NO OF FAMILIES – 2 FAMILY OF 3 MEMBER , 3 OFFICE , 10 SHOP
• OVER HEAD WATER RESERVOIR – 10000 L
• UNDER GROUND WATER RESERVOIR – 10 000L
• SOURCE OF WATER – KOLKATA MUNICIPAL CORPORATION
• ANNUAL WATER REQUIREMENT OF BUILDING – 7,30,000 L

3. DESCRIPTION OF CATCHMENT
• ROOF CATCHMENT – SURFACE TYPE – NEAT CEMENT FINISH
• CATCHMENT AREA – 125 SQ.M
• RUN OFF COEFFICIENT – 0.6-0.75 (CPCD,INDIA)
• AVERAGE ANNUAL RWH POTENTIAL = 151.8 L
Rain Water harvesting potential of a site (m3 ) = (Rainfall (mm)×10-3
)×Area of catchment (m2 )×Runoff coefficient of the catchment surface
• GROUND AREAS ARE NOT INCLUDED
COURTYARD
OPEN SPACE
OVERHEAD TANK
C
E
N
T
R
A
L
A
V
E
KOPALITALA LANE

4. SCOPE & LIMITATIONS
• CONSTRAINS –
1. THE ROOF IS USED FOR RELIGIOUS PURPOSE
2. USED FOR WASHING UTENSILS
3. PROPER SLOPE & DRAINAGE IS ALREADY MADE
4. THE DRAIN ARE CONNECTED WITH SEWAGE PIPE COMING OUT OF TOILET – NO WATER IS HENCE CONSERVED FOR
FUTURE USE
• POSSIBILITIES
1. COULD BE CONNECTED WITH UNDERGROUND WATER RESERVOIR
2. GREEN PAVEMENT , INTRODUCTION OF GREENARY COULD BE DONE ON BUILDING SURFACE
3. GREY WATER AND RAIN WATER (UNTREATED COULD BE REUSED .
• MAXIMUM POSSIBLE RWH VALUE = 273.3 L
1. INCREASE IN CATCHMENT AREA – 100 SQ.M
• POTENTIAL VOLUME VS POSSIBLE VALUE = 80% INCREASE
1. CONSERVATION OF THE ROOF TOP WATER
2. FROM THE CHAJJA AND THE COURTYARD
RELIGIOUS ACTIVITIES IN ROOF

5. RWH DESIGN
RELIGIOUS
PLATFORM
RECREATIONAL
UTENSIL
WASH AREA

6. APPROX COST ESTIMATE
• CREEPER BED IN COURTYARD
1. 4 Inch PVC Pipe, Size/Diameter: 4 Inch , 3 NO: – RS 4050
2. CREEPER –5NO: - RS 4000
3. SOIL – 0.5 BAG – RS 50
4. NUT BOLTS – RS 50
• ROOF FLOORING
1. GREEN LAWN- 90 SQ.M- 968sq.ft - RS 4840
2. 4 Inch PVC Pipe, Size/Diameter: 4 Inch – RS 1350
3. GREY TILES- 25 SQ. M – 270 sq,ft – RS 2000
TOTAL PRICE – RS 16,340
+ LABOUR COST

7. CONCLUSION
WE CAN FIND LOT MANY TYPES OF ROOFS AND THEIR
METHOD OF CONSERVATION OF WATER . SINCE , WE ARE
MOVING TOWARDS A FUTURE WITH VERY LITTLE DRINKING
WATER , USE OF RAIN WATER CAN CUT DOWN THE WATER
DEMAND .
SINCE KOLKATA RECIEVES 1100MM OF RAIN A YEAR (2019 ,
IMD.ORG) THIS ADAVANTAGE CAN BE FRUTIFULLY UTILIZED .
BY GIVING A RAIN WATER A PART OF USE IN OUR DAILY LIVES
, WE CAN BRING CHANGE .
LOT OF THE STATES HAVE FACED WATER SCARCITY SINCE
LAST 5 YEARS , IT HAD BECOME MANDATORY AND IS PART OF
BUILDING LAWS TO HARVEST RAIN WATER
THANKYOU