Project 5 — Water Audit for Water Management

How does the India Meteorological Department warn us that the monsoon is coming, or that a cyclone or heat wave is on its way? It studies records of temperature, humidity, wind and rainfall collected over many years, and looks for patterns that are likely to repeat. This is the power of data.

Data is information collected for a definite purpose. It can be numbers (litres, rupees, millimetres of rain), words (answers in an interview), photographs or videos. Raw data is not useful by itself; we organise it in tables or charts so that we can interpret it and reach conclusions. A farmer who learns from past records that a summer will be hotter and the rains late can delay sowing or choose a crop such as millets that needs less water. Government departments use data to decide when to release water from dams and how much water a growing town will need.

A water audit is a systematic examination of water in a building, home, school or locality: where it comes from, how much is available, how it is used, and where it is lost or wasted. It ends with practical suggestions to save water.

An audit is only as good as its data, so data must be:

• Accurate and authentic — it measures exactly what you said you would measure. If you are counting families who use a borewell, a family using only tanker water must not be counted in.
• Reliable — two people measuring the same thing in the same way should get nearly the same result.
• From a trusted method or source — measured carefully by you, or taken from a dependable source such as a government office, with the method agreed before you start.

In this project you will measure water use in homes, gather official figures about supply and rainfall, analyse both, find wastage points and suggest ways to reduce use. Along the way you will practise skills used by environmental engineers, auditors and planners: careful measurement, polite questioning, honest recording, simple calculation, and clear reporting with sources acknowledged.

India is home to nearly 18 per cent of the world's population but has only about 4 per cent of its fresh water. This water is also unevenly spread. Parts of Assam and Bihar face floods almost every year, while parts of Rajasthan, Marathwada in Maharashtra and the interior of Karnataka face repeated drought. Even within one city, some colonies get water every day while others wait for a tanker.

Droughts are often called natural disasters, but human actions make them much worse:

• Deforestation — fewer trees mean rain runs off quickly instead of soaking into the ground.
• Over-extraction of groundwater — borewells pumping more than the rain puts back make the water table fall year after year.
• Poor farming practices — flooding fields with more water than crops need, or growing very thirsty crops in dry areas.
• Misuse at home and in towns — leaking pipes, overflowing tanks, taps left running, and polluted lakes and ponds.

Small habits add up. A tap left fully open for five minutes while brushing or washing can waste around 45 litres — enough drinking water for a family of four for several days. Meanwhile, somewhere else, a girl may be walking a long distance to fill one pot.

There is good news too. Communities across India have revived traditional systems such as johads and kunds in Rajasthan, baolis (stepwells), and village ponds. Many housing societies and schools now harvest rooftop rainwater and recycle water for gardens and toilets. The government's Jal Jeevan Mission (started 2019) aims to provide a functional tap connection with safe drinking water to every rural household, and the Jal Shakti Abhiyan encourages people to ‘catch the rain’ — to harvest rainwater, renovate water bodies, recharge wells and plant trees with people's participation.

A water audit is your contribution to this effort. By measuring use and wastage in your own locality, you replace vague worry with figures — and figures make it much easier to convince a family, a school principal or a panchayat to act.

What you will need. A notebook and pen; a measuring jar, or a known one-litre bottle in its place; a bucket and mug; a stopwatch or the timer on a mobile phone; a printed or hand-written survey form; a calculator; basic plumbing tools (spanner, wrench, plumber's tape, washers) for the repair activity; and, if available, a computer with a spreadsheet for analysis.

Staying safe.

• Permission and company: always go in a group with a teacher, parent or known adult, and take permission before entering anyone's home or property. Introduce yourselves and explain the purpose.
• Outdoors: be careful near wet, slippery floors, open tanks, wells, ponds and drains. Never climb onto an overhead tank or lean into a well. Carry water, wear a cap and avoid surveying in the hottest part of the day.
• Tools: use spanners and wrenches carefully, and repair taps only with an adult or plumber, after turning off the water supply.
• Internet and privacy: ask your teacher before uploading or downloading anything. Do not share any family's name, address or phone number online. Use data only from reliable sources such as government departments, census reports and national research institutes.

Two kinds of data. An audit needs both:

In this audit, your own primary data will tell you how water is used, and secondary data will tell you how much is available and supplied. When you use secondary data you must always note where it came from and the year, because figures such as population and rainfall change.

Water is measured in millilitres (mL) for small amounts such as a glass, in litres (L) for household use, and in cubic metres (m³) for large amounts such as a town's supply. Remember: 1 L = 1,000 mL and 1 m³ = 1,000 L. In this audit, record everything in litres.

Using everyday containers. You cannot carry a measuring cylinder into every home, so first find the capacity of common containers. Many buckets and cans have their capacity printed on them. If not, fill the container using a known 1 L bottle and count. A typical bucket holds 15–20 L, a mug about 1 L, a steel lota about 0.5 L, an earthen matka 10–15 L. Families can then tell you ‘three buckets for bathing’ and you can convert it into litres.

Machines. Washing machines and RO water purifiers give their water use in the user manual or on the maker's website. A front-loading washing machine may use around 50–70 L per wash, and many ordinary RO purifiers send 2–3 L to the drain for every litre of purified water.

Flow rate. For taps, showers and garden pipes, measure the flow rate in litres per minute (L/min). Open the tap as it is normally used, hold a bucket under it, start the stopwatch, and stop after exactly one minute. Measure the water collected. Repeat twice and take the average.

Water used from flow rate. Once you know the flow rate, you only need to time how long the tap is open:

Water used (L) = flow rate (L/min) × time the tap is open (min)

Storage tanks. The capacity of a cuboid tank is length × breadth × height in metres, giving cubic metres; multiply by 1,000 to get litres. Many plastic overhead tanks have the capacity (500 L, 1,000 L) printed on them. For the big tanks in a locality, the water supply officer can tell you the capacity and how much water is supplied each day.

Measure carefully, write units with every number, and note whether a figure is measured or estimated.

All our water ultimately comes from rain. It reaches us through natural sources — rivers, streams, lakes, springs and groundwater — and man-made sources — dams, reservoirs, canals, wells, borewells, tanks and ponds. From a dam or a treatment plant it travels through canals and pipelines to large storage tanks, and from there to homes and public taps. Some families also depend on hand pumps, private borewells, tankers or bottled water.

For your audit you need to know where your locality's water comes from, how much is supplied, and how many people depend on it. These are secondary data, best obtained from the people who run the supply: the Gram Panchayat office in villages, the Municipal Corporation or municipality, the ward office, or the water supply and sewerage board.

Planning the interview. With your teacher, write to or phone the office to fix a time. Prepare questions in advance and share the work: one student asks, one writes, one keeps time. Useful questions:

• What is the source of water for our locality?
• How much water is supplied per day to a household, and how much per person is planned?
• What problems do you face in supplying enough water to everyone?
• How does rainfall affect supply? Is rainwater stored or harvested anywhere?
• Does supply change between seasons?
• What can families do to help manage water better?

Add your own questions and remove those that do not fit. During the interview, be polite, listen without interrupting, and repeat numbers back to check you have written them correctly, with units. Note the officer's designation, the office and the date — this is your source citation. Thank them, and later send them a copy of your findings.

Mapping. Finally, draw a simple map of your neighbourhood showing water sources and delivery points: wells, hand pumps, borewells, overhead tanks, public taps and the pond or lake, with a key. The official may help you mark ones you do not know. The map makes clear which households depend on which source.

To learn how water is actually used, survey a sample of homes. You cannot visit every house, so each student surveys at least ten families; a group of five students then has data from fifty families, which is a useful sample. Choose families of different sizes and from different lanes, so that the sample represents the locality.

A survey form keeps every interview the same, which makes the data reliable. Prepare one page per family with questions such as:

• Name (or a code number) and number of people in the family.
• How much water is stored each day — e.g. one 1,000 L tank, one 15 L matka, bottles?
• Water used daily for: washing clothes (buckets or machine), washing utensils (tap time or buckets), drinking and cooking (bottles or pots), bathing (buckets, or shower time), and toilet flushing.
• Appliances that use water — washing machine, RO purifier — and how often they run.
• Other uses: washing vehicles, garden, animals.
• Other sources: well, borewell, tanker, bought water.
• What happens to water left over at the end of the day — reused or thrown away?
• Any shortages, and how they manage; water bill, if any.

Converting answers to litres. Families give estimates in buckets, mugs and minutes. Convert immediately using the capacities and flow rates you measured: ‘two buckets of 18 L’ = 36 L. If water comes from an overhead tank and the family is not sure, ask about habits — how many baths a day, how many loads of washing — and calculate. Mark such figures as estimates.

Data integrity. Record exactly what you are told; do not ‘improve’ numbers. Write units every time. Answers that are not numbers (such as ‘we manage by storing in drums’) are valuable notes but cannot be added up, so keep them in a separate column.

Courtesy. Introduce your group, explain the purpose, ask for 15–20 minutes, and stop if the family is busy. Do not ask for phone numbers or photograph people without consent. Use a code (F1, F2…) instead of names in the report to protect privacy.

Back in school, put all the survey data into one table, either in your notebook or in a spreadsheet such as Excel, Google Sheets or LibreOffice Calc. A spreadsheet is a grid of cells, each named by its column letter and row number (B2, C5). Typed formulas do the arithmetic for you.

Setting up the table. One row per family. Columns could be: A – family code; B – number of members; C – drinking and cooking; D – bathing; E – clothes; F – utensils; G – toilet; H – others; I – total per day; J – per person per day. Choose the use-categories that fit what you actually found. Enter every value in litres.

Useful formulas.

• Total for a family in row 2: =SUM(C2:H2) adds C2 to H2.
• Use per person: =I2/B2 divides the total by the number of members.
• Average per person across 10 families in rows 2 to 11: =AVERAGE(J2:J11).
• Highest and lowest: =MAX(J2:J11) and =MIN(J2:J11).

Type a formula in one cell, then drag it down to copy it for every family. If you have no computer, the same calculations work with a calculator; a spreadsheet simply saves time and reduces mistakes.

Average per person is the most important figure. One correct way is to add the total use of all families and divide by the total number of people. (Averaging each family's per-person figure gives a slightly different answer when family sizes differ; say which method you used.)

Looking for patterns. Which use is largest — usually bathing, clothes or utensils? Which families use much more than average, and why — a car washed daily, a garden, a leaking tank, an RO purifier? Which use much less, and is that because of shortage? Note the reasons beside the numbers.

Presenting. A bar graph compares families; a pie chart shows how one family's or the whole sample's water is divided among uses. Give every chart a title, labels and units.

How much water does nature give your area each year? You can estimate it from two secondary figures: the area of your district, block, town or village, and its annual rainfall. Rainfall is measured as the depth of water that would stand on flat ground — for example 800 mm (0.8 m) in a year.

Step 1 – Collect the data from reliable sources: area from the district website or census handbook; rainfall for a stated year from the India Meteorological Department or the state's agriculture or revenue department; population from the census or local office. Record each source and its year.

Step 2 – Convert units. 1 km² = 10,00,000 m² (one million); rainfall in mm ÷ 1,000 = metres; 1 m³ = 1,000 L.

Step 3 – Total rainwater. Volume (m³) = area (m²) × rainfall (m). Multiply by 1,000 for litres.

Step 4 – Share for homes. As a rough planning guide, about 70 per cent of water goes to agriculture and animals, 20 per cent to industry and 10 per cent to domestic use. So domestic share ≈ total × 0.1.

Step 5 – Per person. Divide the domestic share by the population for litres per person per year, then by 365 for litres per person per day.

An example with a village. Area 5 km², rainfall 700 mm, population 4,000.

• Area = 5 × 10,00,000 = 50,00,000 m²; rainfall = 0.7 m.
• Volume = 50,00,000 × 0.7 = 35,00,000 m³ = 350 crore litres.
• Domestic share (10%) = 35 crore litres.
• Per person per year = 35,00,00,000 ÷ 4,000 = 87,500 L; per day = 87,500 ÷ 365 ≈ 240 L.

Limits of this estimate. Not all rain can be used: much evaporates or runs off into rivers, and rain falls in a few monsoon months, not evenly through the year. Also, rivers carry water from where rain falls to people far downstream; everyone in a river basin shares that water. So the figure is a rough guide, useful for comparison, not an exact supply.

Citing sources. Write each figure with where it came from and the year, for example: ‘Rainfall 2024: 700 mm, District Statistical Handbook, published by the district administration.’

Comparing with norms. Now place three figures side by side:

Norms change over time, so note the year and check the latest figure on the Ministry of Jal Shakti website. Discuss: Is your locality using more or less than the norm? Is enough available? If use is far above the norm, where is it going? If it is far below, are families facing shortage? Always state where each figure came from, for example: ‘Jal Jeevan Mission target of 55 litres per person per day, Ministry of Jal Shakti, as reported in a Press Information Bureau release, 2024.’

Ways to increase availability: planting trees, keeping lakes and rivers clean, reducing wastage, recycling water and harvesting rainwater.

Finding wastage points. Walk around your home and school with a notebook. Look for dripping taps, wet patches under pipes or on walls, overflowing overhead tanks, leaking flush tanks (a faint trickle into the toilet pan), and taps that do not close fully. For each, note the location, the type of problem and a photograph if allowed.

Measuring the wastage. Place a mug or bucket under the leak. Start the stopwatch, collect for a fixed time — say 10 minutes — and measure the water collected. Repeat once. Then scale up:

Wastage per day (L) = water collected (L) ÷ minutes collected × 1,440 (there are 1,440 minutes in a day).

For an overflowing tank, time how long it overflows each day and measure the overflow rate the same way as a tap's flow rate.

A table of wastage points, each with litres lost per day, becomes the most powerful page of your report: it shows exactly where to act first — usually where the loss is largest and the repair is cheapest.

Many leaks need only a small repair. Invite a local plumber to school to show you the inside of a tap and the tools used — a spanner, an adjustable wrench, plumber's (PTFE) tape and spare washers. Work only with the plumber or another adult, and turn off the water supply to that tap before starting.

How a common screw-down tap is repaired (in outline):

• Close the stop valve or main supply, then open the tap to let the remaining water drain out.
• Remove the cap or cover on the handle, undo the screw and take off the handle.
• Use the spanner to unscrew the bonnet (headgear) and lift it out. Inside are the rubber washer, an O-ring on the spindle and the jumper valve.
• Replace the worn washer and O-ring with new ones of the same size. A little tap grease on the spindle makes it seal well and turn smoothly.
• Refit the bonnet and handle without over-tightening, which can crack fittings.
• Turn the water back on and check that the tap no longer drips.

If water seeps from a pipe joint, the plumber may rewrap the thread with PTFE tape. A worn washer typically costs only ₹5–10; one fixed drip can save thousands of litres a year.

Reducing use.

• Open taps partly — most of us open a tap fully out of habit.
• Aerators and flow restrictors screwed onto the tap mouth mix air with water or narrow the flow, giving a full-feeling stream with much less water — often cutting flow by half.
• Use a bucket and mug instead of a shower or hose; turn the tap off while brushing or soaping.
• Run washing machines with full loads.
• Fit a float valve or a level alarm on the overhead tank so it stops overflowing.
• Use a dual-flush toilet or place a filled one-litre bottle in an old flush tank.

For each change you make, measure before and after with your flow-rate method, and record the litres saved per day. A saving that is measured is far more convincing than one that is guessed.

Groundwater — the water in wells, borewells and hand pumps — is one of India's most important sources. Water stored underground hardly evaporates, which is a big advantage. But in many districts it is pumped out faster than rain can refill it, so the water table keeps falling. Communities can help rainwater soak back into the ground. Three principles guide this work:

• Hold water where it falls. On sloping land, low earthen walls called contour bunds are built along contour lines (lines joining points of equal height). Rain is held behind each bund instead of rushing downhill, so it soaks in and soil erosion is reduced.
• Slow down running water. A small check dam across a stream slows the flow so that more water seeps into the ground and can also be used for irrigation.
• Help water sink in. A percolation tank, a recharge pit filled with layers of boulders, gravel and sand, or borewell recharge from rooftop rainwater lets water enter the aquifer.

You can volunteer in such work in your area, or help your school set up a rooftop rainwater recharge pit.

Reusing greywater. Used water from bathing, washbasins, washing machines and the kitchen sink is called greywater. (Water from toilets is blackwater and is not reused this way.) Greywater can be reused for watering plants, cleaning floors and courtyards, flushing toilets, or recharge after treatment.

• Simple reuse: water used for washing vegetables or rinsing rice can go straight to the kitchen garden. Water from a washbasin or hand pump area can be led by a channel to plants — provided it is not very soapy.
• Reed bed system: greywater first flows into a sedimentation tank, where solid particles settle. It then passes slowly through a bed of gravel and sand planted with water-loving plants such as Canna indica and Colocasia (arbi). The roots and the tiny organisms living on them take up organic matter and some pollutants, and the cleaner water collects at the outlet for garden use. Rivers clean themselves in a similar natural way — plants absorb dissolved substances, oxygen helps break down organic matter and sunlight kills many germs.

Never drink treated greywater, and keep greywater systems covered so they do not breed mosquitoes.

Estimating future needs. Planners must know how demand will grow. Use your average consumption per person (or the prescribed norm) to estimate:

Extra demand per day = number of new people × consumption per person per day.

Scenario 1: a housing society of 100 homes with about 4 people each is built near your village. New people = 400. If average use is 105 L per person, extra demand = 400 × 105 = 42,000 L per day. If the society follows the urban norm of 135 L, it would need 54,000 L per day.

Scenario 2: a college hostel for 1,000 students opens. At 100 L per student, extra demand = 1,00,000 L per day. Compare this with the present supply: if the locality now gets 3,00,000 L a day, demand rises by one-third. Where will the extra water come from? What saving, recharge or reuse could cover part of it?

Costing your solutions. Every suggestion should carry a cost and a saving:

Prices vary by place and year; note the shop and date. Show which actions are cheapest per litre saved.

Record-keeping. Keep the project file in order: survey forms, measurements with units, the data table, calculations, charts, sources with years, photographs taken with permission, and a log of the periods spent on each activity.

Reporting and action. Share findings with families, the school and the community. You can write a polite letter to the Gram Panchayat or ward office giving your data and suggestions — fixing public taps, promoting greywater for gardens, recharging the borewell near the hand pump, or rainwater harvesting. You might also write a simple computer programme that estimates a family's water use from their answers, or carry out a similar audit of electricity or food waste.

Reflect and explore careers. What surprised you? What three habits will you change? People who do this work include environmental engineers and scientists, water auditors, hydrologists, plumbers, social workers and urban planners.