Costs

March 15, 2010

How much will it cost to catch rain?
When community come together to harvest rain, the per-capita investment goes down. For instance, Panchsheel Park Colony about 1000 residents pooled in Rs 4.5 lakh to harvest more than 170 million litres of water annually.

Rainwater harvesting methods are site specific and hence it is difficult to give a generalised cost. But first of all, the major components of a rainwater harvesting system - rain and catchment area - are available free of cost. A good proportion of the expenses would be for the pipe connections. By judiciously fixing up the slopes of roofs and location of rainwater outlets, this could be brought down considerably. However the cost varies widely depending on the availability of existing structures like wells and tanks which can be modified and used for water harvesting.

 Typically, installing a water harvesting system in a building would cost between Rs 2,000 to 30,000 for buildings of about 300 sq. m. The cost estimate mentioned above is for an existing building. For instance, water harvesting system in the CSE building in Tughlakabad Institutional Area, Delhi, was set up with an investment of Rs 30,000 whereas those in the model projects ranged between Rs 70, 000 and Rs 8 lakh. The costs would be comparatively less if the system were incorporated during the construction of the building itself.

 It is easier to calculate the payback when the rain water harvested is used for storage as it saves money spent on buying water from tankers or private suppliers. Recharging groundwater has less tangible benefits but none the less is very crucial and highly recommended.

Some basic rates of construction activities and materials have been given here, which may be helpful in calculating the total cost of a structure. The list is not comprehensive and contains only important activities meant to provide a rough estimate of the cost.

 

S.No.
Item
 
Delhi
Mumbai
Pune
Rajkot
Chennai
Kolkata
1
Ferrocement tank (above or below groundwater level)
litre
 
3.00--above the ground
--
4.00-- above the ground
   
2
PVC
litre
6.00
4.25
7.00
6.00
3.00
5.4   
3
RCC
litre
10.58
7.00
4.50
4.00
 
5.69
4
Metal tank
litre
 
6.00
5.00
12.00
 
12.88
5
Drain pipe (PVC)
m
380—6” dia
750--6” dia
450--6” dia
250--6” dia
55-3.5” dia
217.80 and 198.00 for UPVC pipe (Single socket 4 “ dia and double socket 4” dia respectively)
414.45 and 842.95 for GI pipe (2” dia and 4”  dia respectively)
6
Pipe laying and fitting
m
 
--
135
50
200
32
7
Collection chambers
Each
1800----(450 mm x 450 mm)
6000—600 mm x 900 x 600 mm
2700--(450 mm x 450 mm)
1500--(450 mm x 450 mm)
 
7177.15 (800 mm x 800 mm x 1200 mm)
8
Filter material
 
2500/cum--Boulders of 40-100 mm, gravel of size 3 mm to 10 mm and coarse sand of 1 to 2mm inclusive of transport, labour charge, taxes, duties.
10000
8000 (only sand)
300 (sand)
200-road jelly of 12 mm dia
 
9
Underground sump (brick work)
litre
3.50
3.00
3.50
--
   
10
Gutter
 
750 (PVC)
400
250 (with metal grating)
--
120-GI/tin sheet
326.60
11
Elbow
   
--
--
--
   
12
First flush valve
   
1000 (PVC)
1300 (PVC)
--
 
6500
13
Chlorination
   
-----
----
---
   
14
Collection tap
Each
 
----
300
---
 
210 (bib cock)
15
Excavation (hard rock or sedimentary)
cu m
Soft soil-250, hard rock- 700
300 (up to 1.5 m below G.L. in hard rock)
233 (in all sorts of terrain
100 (in hard rock)
36 (in hard rock)
41.87 (sedimentary terrain)
16
PCC (PCC base)
cu m
3200
3500
3092
2400
 
2748.60
17
Brick wall (4.5 inch or 9 inches)
cu m
9"--3200, 4.5"--500
3000 (4.5 inches)
2804 (4.5 inches)
2300 (4.5 inches)
1375 (4.5”)
3292.8 for 5” and 3231.20 for 10”
18
Plastering ( with fine sand how many inches , with water proof or without water proof)
cu m
250
125 (12mm thick-Internal Plaster)
207 (12mm thick-Internal Plaster)
120 (12mm thick-Internal Plaster)
40 (12mm thick-Internal Plaster)
81 (20 mm thick) and 69 (15 mm thick)
19
RCC slab
cu m
1200
8000
3500
3500
 
10809.17
20
Removal of debris
 
1500/truck
2000 –L.S.
200/cu m
100 –L.S.
   
21
Drilling of One Recharge Bore ( DTH or Hand bore set)
m
hand bore—600 mechanical--1000/m
10000
197
225
160 for 7” dia bore
931.00 (for first 50 m), 745.00 (next 50 m) and 780.00 (then next 50 m) with 550 mm dia casing
22
Casing ( PVC or MS casing  )
   
500-- PVC (6”  dia)
450--PVC (6”  dia)
1000--PVC (6”  dia)
   
23
Additional items
       
15 % is fixed for contractor’s profit
For recharge pit: Cost of RCC ring 3' (Precast rings )--36, Cost of RCC ring 4'--110, Cost of RCC ring 5--130', Labour charges—L.S.--200
As per PWD schedule of West Bengal