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UNDER THE GUIDANCE OF
Dr. B. Nagamalleswara RaoProfessor & Head
DESIGN AND IMPLEMENTATION OF ROOFTOP RAINWATER HARVESTING SYSTEM(RRHS)
FOR D-BLOCK OF VNRVJIET CAMPUS By
• G.Sandhya Rani (10071A0174)• J.Sai Kiran (10071A0176) • K.Sravan kumar (10071A0185)
Department of Civil Engineering VNR Vignana Jyothi Institute of Engineering &Technology,
Bachupally, Nizampet (S.O), Hyderabad-500090, AP
• B.Rani (11075A0117)• M.Mahesh (11075A0124)
CONTENTS
1. INTRODUCTION
2. OBJECTIVES
3. LITERATURE REVIEW
4. METHODOLOGY
5. TIME SCHEDULE
6. APPLICATIONS
7. CONCLUSION
8. REFERENCES2
1.INTRODUCTION
Water is the most common or major substance on earth, covering more than 70% of the planets surface. The total amount of water on earth remains constant.
The rapid growth in population together with industrial development, are putting stress on the natural ecosystems.
Water supply mainly depends on the natural water bodies likes lakes and artificial water bodies like reservoirs etc.
Due to the Urbanisation and rapid growth in the population many lakes has been lost and the majority of the present were polluted .
This results in the imbalance of demand and supply of water.
To overcome supply shortages, many households, businesses and industries fall back on groundwater reserves. The number of bore wells increased.
1.INTRODUCTION
This is leading to the fall in the ground water table.
One possible strategy could be the usage of rainwater in order to overcome the shortage of water.
Rain water harvesting means to make optimum use of rain water at the place where it falls i.e. conserve it and not allowing it to drain away.
The water can be used as drinking water, water for livestock, water for irrigation or to refill aquifers in a process called ground water recharge.
The rainwater falling on roof of residential buildings and institutions can be an important contribution to the availability of water.
Hydrological cycle
ABSTRACT
Roof water harvesting is being widely promoted as a panacea for the growing drinking water crisis in India and many underdeveloped and developing countries. This project analyzes the scope, physical feasibility and economic viability of roof water harvesting systems. The economic viability as a supplementary source of domestic water supply seems to be poor in urban areas, when compared to augmenting the supplies from the existing public systems. The incredibly low rates charged for domestic supplies by urban water utilities and government subsidies for RWHS would not only lead to the urban elite increasing their access to water supplies, while the burden on water utilities would remain unchanged. This will lead to greater inequities in access to water supplies. At the same time, in rural areas with dispersed populations and hilly areas, RWHS may be economically viable as a supplementary source to already existing public water supply schemes.
6
2.OBJECTIVES
Design of rain water harvesting system components.
Implementation of rain water harvesting system in D Block of
VNRVJIET campus
Cost benefit analysis
3. LITERATURE REVIEW
ANIL AGARWAL (2013): Manual on Urban Rainwater Harvesting “Catch Water Where it Falls”
KIRAN. A, NIKHIL. T, R HARISH, J KULKARNI (2012): Harvested Rain Water for Drinking- Research Paper.
ROHITASHW KUMAR, THAMAN S, AGRAWAL G. and SHARMA POONAM(2011): Rain Water Harvesting and Ground Water Recharging in North Western Himalayan Region for Sustainable Agricultural Productivity- Research Paper.
M. DINESH KUMAR, ANKIT PATEL(2005) : Rainwater Harvesting in the Water-scarce Regions of India potential and Pitfalls-Research paper
ACHAYRA, B. P. (2004). Managing Water Sector Institution - HMWSSB Experience (Presentation). Hyderabad Metropolitan Water Supply and Sewerage Board, Hyderabad.
SIVARAMAN , K.R. & THILLAI GOVINDARAJAN S.. (2003), Manual on Rainwater Harvesting. Chennai, Akash Ganga.
ARIYABANDU R. D. S. (2003). Very-Low-Cost Domestic Roof Water Harvesting in the Humid Tropics: Its Role in Water Policy. Sri Lanka Domestic Roofwater Harvesting Research Programme.
4. METHODOLOGY
Collection of the building data.
Collection of rainfall data of past 10 years.
Design of RWHS components
Implementation
COMPONENTS OF RWHS
10
• Roof Catchment• Drain pipes• Down pipes• First Flush Pipe• Storage Tank• Recharge Pit
Drain Pipe
Storage tank
Down pipe
First Flush Pipe
DESIGN OF RWHS COMPONENTS
1.Roof catchment
2.Calculation of Volume of Runoff
3.Design of Rectangular Storage Tank
4.Design of Conduits
5.Design of Recharge Pit
11
DESIGN OF RWHS
1.Roof catchment: • The area of the roof from which the rain water is
collected.• The total roof area of D block = 2351 m2
12
13ALL DIMENSIONS ARE IN MM
ROOF PLAN
DESIGN OF RWHS
Area of catchment = 2351 m2
Annual average rainfall = 887 mm
= 0.887m
Runoff co-efficient = 0.85
Volume of runoff = area of catchment x annual
average rainfall x runoff
co-efficient
= 2351 x 0.887 x 0.85
= 1773 m3/yr 14
2.Calculation of Volume of Runoff:
DESIGN OF RWHS
Average value of highest
rainfall in rainy days = 94mm =0.094m
Volume of Runoff = 2351 x 0.094 x 0.85
= 188 m3/day
For economical design considering half of the discharge as volume of tank
Volume of tank = 94 m3
15
DESIGN OF RWHS
Assume depth of tank = 2m
Area of tank = volume of the tank/depth
= 94/2 = 47m2 = 50m2(approx.)
Taking Length: Breadth ratio as 2:1
L = 2B
2B x B = 50
B = 5m
L = 10m
16
3.Design of Rectangular Storage Tank:
ALL DIMENSIONS ARE IN METERS
Storage Tank
EXISTING PIPE DETAILS
S.No Diameter(mm)
No of Pipes Length of Pipe(m)
1 110 4 22.00
2 110 2 21.77
3 140 1 21.34
4 150 1 21.40
5 150 1 21.37
6 150 1 14.64
7 150 1 11.00
17
DESIGN OF RWHS
Taking diameter of pipe = 110mm = 0.11m
Average value of highest
rainfall in rainy days = 94mm =0.094m
Taking number of pipes = 10
Volume of water that can be
discharged through 10 pipes = 2351×0.094×0.85
= 188 m3/day
Volume of water that can be
discharged through each pipe = 188/10 = 18.8m3/day
= 2.17×10-4 m3/sec
4.Design of Conduits:
DESIGN OF RWHS
The recharge pit is designed for one third of discharge
Volume of recharge pit = 62m3
Assuming depth of recharge pit = 3m
Area of the recharge pit = 62/3 = 20 m2
Taking Length: Breadth ratio as 2:1
L = 2B
2B x B = 20
B = 3.2m
L = 6.4m 19
5.Design of Recharge Pit:
ALL DIMENSIONS ARE IN MM
ESTIMATION & COSTING
Storage Tank Earth Work Excavation
Length of excavation
Width of excavation
Depth of excavation
Total volume of excavation
Cement Concrete in Foundation
Length at sides
Width at sides
= 10 +(0.3/2) + (0.3/2) = 10.3 m
= 5 - (0.3/2) -(0.3/2) = 4.7 m
= 2 + 0.3 + 0.3 = 2.6 m
= Length x Width x Depth
= 10.3 x 4.7 x 2.6
= 125.86 m3
= 10 + (0.3/2) + (0.3/2) = 10.3 m
= 5 -(0.3/2) - (0.3/2)= 4.7 m
20
Depth of layer
Total volume of cement concrete in
foundation Brick Work (Long wall & Short wall Method)
Taking width of wall 30cm we get
Long wall length
Short wall length
Long wall quantity
Short wall quantity
Total quantity
= 0.3 m
= Length x Width x Depth
= 10.3 x 4.7 x 0.3
= 14.523 m3
= 10 +(0.3/2) +(0.3/2) = 10.3 m
= 5 -(0.3/2) -(0.3/2) = 4.7 m
= 2 x 10.3 x 0.3 x 2 = 12.36 m3
= 2 x 4.7 x 0.3 x 2 = 5.64 m3
= 12.36 + 5.64 = 18.00 m3
21
Plastering Work
Plastering on length side
Plastering on width side
Plastering on flooring
Total area of plastering
R.C.C Work for Slab
Length of Slab
Width of Slab
Depth of slab
Total Quantity
= 2 x 10 x 2 = 40 m2
= 2 x 5 x 2 = 20 m2
= 10 x 5 = 50 m2
= 40 + 20 + 50 = 110 m2
= 10 m= 5 m= 0.15 m= Length x Width x Depth= 10 x 5 x 0.15= 7.5 m3
22
Recharge Pit Earth Work Excavation
Length of excavation
Width of excavation
Depth of excavation
Total volume of excavation
Brick Work (Long wall & Short wall
Method)
Taking width of wall 30cm we get
Long wall length
Short wall length
= 6.1 +(0.3/2) +(0.3/2) = 6.4 m
= 2.9 -(0.3/2) -(0.3/2) = 2.6 m
= 2 m
= Length x Width x Depth
= 6.4 x 2.6 x 2= 33.28 m3
= 6.1 + (0.3/2) +(0.3/2) = 6.4 m
= 2.9 -(0.3/2) -(0.3/2) = 2.6 m
23
Long wall quantity
Short wall quantity
Total quantity
Plastering Work
Plastering on length side
Plastering on width side
Total area of plastering
= 2 x 6.4 x 0.3 x 2 = 7.68 m3
= 2 x 2.6 x 0.3 x 2 = 3.12 m3
= 7.68 + 3.12 = 10.80 m3
= 2 x 6.4 x 2 = 25.6 m2
= 2 x 2.6 x 2.82 = 10.4 m2
= 25.6 + 10.4 = 36 m2
24
ESTIMATION OF MATERIALS
Storage Tank (1:2:4)Cement Concrete in Foundation
Total Volume
Volume
Add 25% for Wastage
Cement
Sand
Coarse Aggregate
Brick Work
Total Volume
For 1 m3 number of bricks
For 18 m3 number of bricks
= 14.523 m3
= 14.523/1+2+4 = 2.07 m3
= 2.07 + 0.25 x 2.07 = 2.593 m3
= 2.593 m3 = 75 Bags
= 2.593 x 2 = 5.186 m3
= 2.593 x 4 = 10.373 m3
= 18 m3
= 500
= 18 x 500 = 9000
25
Wet Volume
Add 25% for Wastage
Net Volume
Cement
Sand
Plastering
Total Area (12 mm Thick)
Wet Mix Mortar
Add 30% for Filling Joints
Increase 25% by Dry Volume
= 18 – (9000 x 0.19 x 0.09 x 0.09)
= 4.15 m3
= 4.15 + 0.25 x 4.15 = 5.186 m3
= 5.186/1+4 = 1.037 m3
= 1.037 m3 = 30 Bags
= 1.037 x 4 = 4.15 m3
= 110 m2
= 12 x 110 / 1000 = 1.32 m3
= 1.32 x 1.3 = 1.716 m3
= 1.716 x 1.25 = 2.145 m3
26
For 1:4 Cement Sand Mortar
Cement
Sand
Steel Bars
Main Steel
Number of Straight Bars
Number of Bent-Up Bars
Length of Straight Bar
Length of Bent-Up Bar
Total Length of Straight Bars
Total Length of Bent-Up Bars
= 2.145/1+4 = 0.43 m3
= 0.43 m3 = 13 Bags
= 0.43 x 4 = 1.716 m3
= 84
= 84 – 1= 83
= 10 – 0.04 + (18 x 0.01) = 10.14 m
= 10.14 + 0.08 = 10.22 m
= 84 x 10.14 = 851.76 m
= 83 x 10.22 = 848.26 m
27
Total Weight of Main Steel (10 mm
Diameter Bars @ 0.62 kg/m)
Distribution Steel
Number of Straight Bars
Number of Bent-Up Bars
Length of Straight Bar
Length of Bent-Up Bar
Total Length of Straight Bars
Total Length of Bent-Up Bars
Total Weight of Distribution Steel (8
mm Diameter Bars @ 0.39 kg/m)
Total Weight of Steel in Storage Tank
= (851.76 + 848.26) x 0.62 = 1054 kg
= 20
= 20 – 1 = 19
= 5 – 0.04 + (18 x 0.008) = 5.104 m
= 5.104 + 0.08 = 5.184 m
= 5.104 x 20 = 102.08 m
= 5.184 x 19 = 98.49 m
= (102.08 + 98.49) x 0.39 = 200.57 kg
= 1054 + 200.57 = 1254.57 kg
= 12.54 Q
28
Recharge Pit
Total Volume
For 1 m3 number of bricks
For 10.8 m3 number of bricks
Wet Volume
Add 25% for Wastage
Net Volume
Cement
Sand
= 10.8m3
= 500
= 10.8 x 500 = 5400
= 10.8 – (5400 x 0.19 x 0.09 x 0.09)
= 2.489 m3
= 2.489 + 0.25 x 2.489 = 3.11
= 3.11/1+4 = 0.622m3
= 0.622m3 = 18 Bags
= 0.622 x 4 = 2.48m3
29
COST FOR WORK AND MATERIALS
Cost of Earth Work in Excavation per
cubic meter
Cost of Cement Concrete in Foundation
per cubic meter (1:4:8)
Cost of Total Brick Work per cubic meter
Cost of Earth Work in Filling per cubic
meter
Cost of R.C.C Work per cubic meter
(Including Steel)
Cost of Plastering per square meter (12
mm thick) (1:3)
Cost of Pipe per meter (75 mm diameter)
Cost of One Bent (75 mm diameter)
= Rs.100/-
= Rs.2,000/-
= Rs.1,300/-
= Rs.20/-
= Rs.3,500/-
= Rs.60/-
= Rs.35/-
= Rs.20/-30
Cost of One Opening on R.C.C Slab
Cost of One Gate Valve
Cement(per bag)
Fine Aggregate(per cubic meter)
Coarse Aggregate(per cubic meter)
Steel(Per Quintal)
Brick(Per Piece)
Cost of Storage Tank:
Cost of Earthwork in excavation
Cost of cement concrete in
foundation
= Rs.400/-
= Rs.200/-
= Rs.240/-
= Rs.1120/-
= Rs.1200/-
= Rs.4500/-
= Rs.5/-
= Volume of excavation x Cost of
excavation per cubic meter
= 125.866 x 100 =Rs.12586.6/-
= Volume of cement concrete x Cost
of cement concrete per cubic meter
= 14.523 x 2000
=Rs.29046.00/-
31
Cost of Brick work
Cost of Plastering
Cost of RCC work in slab
= Volume of Brick work x Cost of
Brick work per cubic meter
=18 x 1300
= Rs.23400.00/-
= Total Area of Plastering x Cost of
Plastering per cubic meter
= 110 x 60
= Rs. 6600.00/-
= Volume of RCC work in slab x Cost
of RCC work in slab per cubic meter
= 7.5 x 3500
= Rs.26250.00/-
32
Cost of Recharge pit
Cost of Earthwork in excavation
Cost of Brick work
Cost of Plastering
= Volume of Earthwork in excavation x Cost of Earthwork in excavation per cubic meter
= 33.28 x 100
= Rs.332.80/-
= Volume of Brick work x Cost of
Brick work per cubic meter
= 10.8 x 1300
= Rs.14040.00/-
= Total area of Plastering x Cost of
Plastering per cubic meter
= 36 x 60
= Rs.2160.00/-
33
COST OF PROJECTCost of the Project = Total Cost of work for storage tank + Total Cost of work
for Recharge Pit + Cost of Materials
Cost of the Project = Rs. 97882.6 + Rs. 16532.6+ Rs.240098.32
= Rs. 354513.52/-
Cost of Tools and Plants =1.5% of Cost of Project
=0.015 x 354513.52
= Rs.5317/-
Cost of Contingence = 5% of Cost of Project
= 0.05 x 354513.52
= Rs.17,725.68/-
Cost of Work Charge Establishment =2% of Cost of Project
= 0.02 x 354513.52
= Rs.7090.27/-
Total Cost of Project = Cost of the Project + Cost of Tools and Plants + Cost of Contingence + Cost of Work Charge Establishment
= Rs.4,48,459/-
34
COST BENEFIT ANALYSIS
Volume of water collected in a year
through RWHS
Volume of water collected in year
excluding 20% overflow
We use daily 1 tanker of 20,000 liters
capacity
Number of tankers
Cost of one tanker
Volume of water used per day
= 1773 m3/yr
= 1773000 lit/yr
= 1773000 x 0.8
= 1418400 lit/yr
= 1
= Rs. 1000/-
= No of tankers x Capacity of tankers
= 1 x 20,000
= 20,000 liters35
Cost of one liter of water
Total cost of water purchased per
year
Total cost of water that can be
collected by RWHS
Amount of money saved
Total amount spent on constructing
tank and recharge pit
Number of years required to recover
the amount spent on construction
= Rs. 0.05/-
= Cost of water purchased in a day x
No of days water used in a year
= 1000 x 242
= Rs. 2,42,000/-
= 1418400 x 0.05
= Rs. 70,920/-
= Rs. 70,920/-
= Rs. 4,48,458/-
= 6.3 Years
36
RAINFALL DATA
Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec2003 0 10.7 11.7 27.3 0 65.5 265 144 54.9 168 0 0
2004 38.9 0.6 32.4 59 41.9 29.4 221 68.7 118.2 72.8 0.2 0
2005 39.7 10.3 18.7 24.8 21.8 88.9 369 115 220 221 0 0
2006 0 0 41.8 67.9 100 83.8 192 237 206 15.7 52.2 0
2007 0 0 0 23 11.5 113.3 92.8 214 266 18.1 21 0
2008 0 69.2 166 13.8 20.8 40.2 96 464 199 48 48 0
2009 0 0 2.1 23 17.3 69 55.5 353 145 69.6 28 4.4
2010 6.3 2.7 0 0.6 17.4 150.8 339 216 231 55.5 46.8 15.2
2011 0 25.2 1.7 6.9 1.7 35.6 185 234 76.9 70 8.4 0
2012 0.3 0 0 18.3 4.8 132 232 143 114 78.1 39.5 0
2013 0.3 17 0 74.5 10.2 203.2 197 124 155 239 14 0
37
5.TIME SCHEDULE
38
S.NO ACTIVITY DURATION DATES
RESCHEDULED DATES STATUS
1. LITERATURE REVIEW
6 WEEKS 23.09.2013 -
02.11.2013
23.09.2013 -
02.11.2013COMPLETED
2. DATA COLLECTION 4 WEEKS 04.11.2013 -
30.11.2013
04.11.2013 -
30.11.2013COMPLETED
3. DESIGNING 9 WEEKS 02.12.2013 -
03.02.2014
02.12.2013 -
03.02.2014COMPLETED
4. COST BENEFIT ANALYSIS AND
DOCUMENTATION
4 WEEKS 04.02.2014 -
04.03.2014
04.02.2014 -
31.03.2014COMPLETED
5 IMPLEMENTATION 4 WEEKS 05.03.2014 5.04.2014 ONWARDS
6. APPLICATIONS
To overcome the inadequacy of water to meet our demands.
To arrest decline in ground water levels.
To increase availability of ground water at specific place and time and utilize rainwater for sustainable development.
To increase infiltration of rainwater in the subsoil which has decreased drastically in urban areas.
To reduce the expenditure spent on water.
7. CONCLUSION
Since VNR Vignana Jyothi Institute of Engineering and Technology has no water supply through pipes, the institute has to buy the water through tankers.
Daily 1 tanker supply the water to the institute, each tanker costs Rs1000/-, having a capacity of 20,000 liters. It is taking Rs.4,48,459/- for total construction of tank and recharge pit.
The amount of money saved in each year through rain water harvesting is Rs.70,920. The amount spent will be recovered in 6.3 years.
In order to save the expenses to some extent on buying water this “Rooftop Rainwater Harvesting System” has been designed.
The water which we get from roof of the building during rainy days are collected and stored.
The water which is collected is set to re-use for gardening, flushing purposes so that the expenses can be reduced to some extent. 40
8. REFERENCES
ANIL AGARWAL (2013): Manual on Urban Rainwater Harvesting “Catch Water Where it Falls”
KIRAN. A, NIKHIL. T, R HARISH, J KULKARNI (2012): Harvested Rain Water for Drinking- Research Paper.
ROHITASHW KUMAR, THAMAN S, AGRAWAL G. and SHARMA POONAM(2011): Rain Water Harvesting and Ground Water Recharging in North Western Himalayan Region for Sustainable Agricultural Productivity- Research Paper.
RAMACHANDRAIAH, C. (2007). Hyderabad’s Water Issues and the Musi River, Need for Integrated Solutions. Draft version of the Paper presented in the International Water Confe-rence, Berlin during 12-14 September 2007.
ACHAYRA, B. P. (2004). Managing Water Sector Institution - HMWSSB Experience (Presen-tation). Hyderabad Metropolitan Water Supply and Sewerage Board, Hyderabad.
SIVARAMAN , K.R. & THILLAIGOVINDARAJAN S.. (2003), Manual on Rainwater Har-vesting. Chennai, Akash Ganga.
ARIYABANDU R. D. S. (2003). Very-Low-Cost Domestic Roof Water Harvesting in theHu-mid Tropics: Its Role in Water Policy.Sri Lanka Domestic Roofwater Harvesting Research Pro-gramme.
42
THANK YOU