Rain Water Harvesting

Overview

Rain Water – We can either reign it in or drain it out.  

All the life sustaining essentials are free in nature. At times our collective arrogance as more evolved and intelligent species makes us – miss the woods for the trees.  Humanity seems to have successfully jeopardized the essentials which are Sunlight, Rain and Air.

All of us have heard the phrase Water Water everywhere but not a drop to drink…The sentiment continues to hold true. One of the reasons for drinking water depletion is Agriculture followed by Industrialization. As we learned to harvest nature and its other deposits to our advantage, we started the parallel process of slowly but surely effecting the basic DNA of the BIO CAPACITY of the planet.  What is Bio Capacity – in simple terms it is the Capacity of the earth to produce the resource required and absorb the waste. The day we exceed that, the process of pollution starts. This is the beginning of inequality.

Sorry for meandering like the Amazon river…I was trying to draw or show the big picture first and then draw you to the sub plot.

This is not a rant about everything wrong in society.but about how we are powerful enough as individuals and then as a collective to make a change.  

We can choose our calling..Mine /our( i.e spectrum) is to harvest water back into the earth…starting at the local community level.  Rain water harvesting in simple terms means to collect and store rain water for future use.

Rain Water can be harvested in several ways –

 Check dams can be built, water reservoir can be built, bore wells can be recharged, water collected from terraces can be used in more than one, In Hilly terrains  Retention  ditches can be made, Planting pits, Bunds. The list is pretty long based on the topography. 

What is rain water harvesting?

Rain Water Harvesting is the collection and storage of rain, rather than allowing it to drain off. The collected water is redirected to tanks, cisterns, deep pits, wells, shafts, bore wells, aquifer’s or a reservoir with percolation. Storm water harvesting differs from Rain water harvesting.

What is bore well recharge?

 A simple explanation could read something like this. Channelizing the rain water which collects on flat terraces, in such a way that it is taken to the mouth of the bore well / a reservoir built close to the bore well. Slowly but surely the water will start seeping back into the earth. Over a few monsoons the natural aquifer will have more water and the water level in the bore well will rise.

Why now?

We have just 2 sources of drinking water – Rain and wells (which draw water from under groud aquifers) Both these sources are getting scare with each passing year. We need  to act now. Keeping this in mind governments across the globe are working towrads ground water recharge and water reserviors

As per a Government ruling passed by  government of Maharashtra  all new building constructed post 2002 should  not be given a completion certificate without the implementation of  rain water harvesting systems. 

Spectrum’s new mission

SPECTRUM has decided to take on the arduous project of bore well recharge in PMC schools across Pune city. We have a  5 year  plan for  recharging borewells in Pune city. We would like to do 25 borewells in the next five years in different Municipal schools areawise. (Funds permitting we can do more)

Why municipal schools ?
  • Most of the municipal schools were built pre 2002..thus do not have the rain wtaer harvesting systems.
  • PMC schools typicall have flat roofs , making  water  collection easy.
  • Most schools already have borewell which are operational
  • Pmc schools have large play ground which are not concretised (helps in percolation)
  • These schools are built around basti’s, thus in the long run  benifiting the entire neighbourhood.
  • Inshort  ideal sites for rainwater harvesting.

How much water can be collected every monsoon. – The data varies city to city based on the average annual rainfall . Details for Pune city are

  • Average rainfall in pune is 700/750 mm annually
  • 1 sq ft collects about 70 litre of water per monsoon season
  • The water saved/collectable is the terrace area into 70.
  • This water can either be stored or channalised back into the ground.

(1000 sqft of catchment area collectes 10,000 litres of rain for every 100 mm of annual rainfal. Pune has 750 mm thus per sq ft we can collect -70 litres annually.)

Criteria for selection of schools

Work  areawise.

The school must have an operational bore well

Open playground (preferable)

 In the 1 st year (2019/2020) we did 3 schools in a 5 km radius. The idea is to maximise the impact of the excersise taken up.

Names of Schools where bore well recharge has been done

1)Babu Rao Katke school, Baner. Terrace area 8000 sq ft = 70*8000 = 5,60,000 liters of water

2)Ahilyabai Holkar school, Baner Road. Terrace area 6500 sq ft = 70*6500 = 4,55,000 liters of water

3)Venutai Yashvantrao Chavan PMC school, Sutarwadi Terrace area 6000 sq ft = 70*6000 = 4,20,000 liters of water

 We have sucefully finshed recharging of borewells in the above schools

We have shortlisted 2 big schools for 2020/21

The names of these schools are SwamiVivekanand School Ghorpadiwith a catchment are of about 9000 sq feet and Ghorpadi Village Highschool with a catchment are of close to 20,000 sq feet. These schools fall under the Poona Cantontment Board (PCB) there are around 20 schools under the PCB. However all the schools do not have pre existing borewells. The solution is not to dig a borewell. By doing so we are putting more pressure on the ground water. We should focus on recahrging existing borewells and we will see dividents in a few years.

Process to start work

First we identify the school. We meet with the principal of the school and explain to them what we want to do. Most principals are very happy as they know the advantages but are not empowered enough to deman for it from the local administration. Once they school authorities  are ok we need to get the permission from the PMC through the local corporator, as all these schools come under the municipal administration. 

We have not faced too many challenges as the corporators are more than happy that their work is being done by private citizens.. having said that minor hicups do come up.

Once the written approvals are in place – the schools are assessed for viability of the project, post which a deatiled quotation is sought.

Spectrum funded  the first school from its own kitty… but we realised that we need to raise funds from external sources too as these projects are pretty expensive.Keepig this in mind..we did our first fund raiser and raised enough money for the second school. The 3 rd school was funded by our sister concern. Our plan to fund the furture schools involves 2 things. 1) We are planning to raise funds through a crowd funding campaigain, secondly we will like the beneficiary school to put in a small percentage of money so that there is a sense of ownership an involvement.

Spectrum volunteers have furter  decided to spread awareness regarding the new education policy proposed by the gvernment to the the students of the schools where we will be doing our RWH projects.

How do you check the efficacy of RWH if we recharge a bore well

How do we know that recharge is happening. Broadly there are 2 ways of doing it. One is the scientific method of doing an accurate measurement using advanced instruments. The other is the rope method, crude but effetive. Throw a rope with markings into the well. You will know how deep you need to go to fetch water. Post the monsoon again measure this. It will increase drasticaly… we should measure it every year around the same time in the non monsoon period.. a few years post RWH we will find the water level rising. 

Things to keep in mind while choosing a borewell for recharge.

  • The bore well should not be a dry one
  • Must test the water quality.
  • Ensure drain water or sewage water is not getting mixed
  • If it is and we recharge the bore well we will be contaminating the ground water further.

Things to keep in mind post implementing the re charge of bore wells using rain awter. We must regularly check the pipers. Leakage or broken piper will negate the whole idea. Secondly pre monsoon we must chek that the openings of the pipes from where water is collected is cleaned, all dry leaves must be removed to  ensure that there is no blockage… the reservior mesh should also be intact at all times.

Challenges faced  by Spectrum

One of the biggest challenges we are facing is in getting the schools/ corporators to fund us the small percentage we are asking for. Getting money from any government agency is an uphill task. The irony is that private agencies are funding upto 90 pecent  in the work to be done by the Municiapl Corporations..inspite of that  the 10 % contribution just does not seem to be coming our way. Every corporator is allocated  funds to be spent on his ward…ths money never seems to be used for what it is meant to be.

Swapna Damerla

Spectrum Member

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