1 Person
2 People
3 People
4 People
5 People
6+ People
Low (Shower only, eco appliances)
Average (Daily showers, dishwasher)
High (Baths, garden hose, power shower)
We've estimated this based on occupants. You can edit this figure if you know your exact meter reading.
This value can be found on your old water bills. It is based on the property value from 1990.
Estimated Annual Charges (2024/25 Rates)
Fresh Water Charges:£0.00
Sewerage Charges:£0.00
Standing Charges (Fixed):£0.00
Total Annual Bill:£0.00
Estimated Monthly Direct Debit:£0.00
Understanding South West Water Rates
Living in the South West of England often means facing some of the highest water rates in the UK due to the extensive coastline and rural infrastructure maintained by South West Water. This calculator helps you estimate your annual water and sewerage bill whether you are on a meter or paying via Rateable Value (RV).
How the Calculation Works
South West Water bills are generally split into two main categories: Water In (Potable Water) and Water Out (Sewerage/Wastewater).
Current Estimation Logic (2024/25 Baseline):
For this calculator, we utilize average unit rates typical for the region:
Metered Water: ~£2.11 per cubic meter (m³).
Metered Sewerage: ~£3.44 per cubic meter (m³) at 95% return to sewer.
Standing Charges: Fixed fees applied to all accounts to cover maintenance and billing administration.
Metered vs. Unmetered Billing
It is crucial to choose the correct billing method in the calculator above:
1. Metered Customers
If you have a water meter, you pay for exactly what you use. The calculator estimates your volume based on the number of occupants and your usage habits:
Low Usage: Approx 40-45 m³ per person/year.
Average Usage: Approx 50-55 m³ per person/year.
High Usage: Approx 65+ m³ per person/year.
Note: Sewerage for metered customers is usually calculated on 95% of the fresh water used (assuming 5% is used in the garden or for drinking and doesn't return to the drain).
2. Unmetered (Rateable Value)
If you do not have a meter, your bill is fixed based on the Rateable Value (RV) of your home. This value was set in 1990 and does not change with current house prices. If you feel your RV bill is too high, switching to a meter can often save money for smaller households.
Tips for Reducing Your Water Bill
Switch to a Meter: If you have more bedrooms than people in your house, a meter is usually cheaper.
WaterButts: Collect rainwater for the garden to avoid using expensive treated tap water.
Fix Leaks: A dripping tap can waste huge amounts of water over a year, inflating metered bills.
Assessed Charges: If you cannot fit a meter but want one, ask South West Water about an "Assessed Charge" which is often cheaper than Rateable Value.
// Constants for South West Water Estimates (Approximate 2024/25 Blended Rates)
var RATE_WATER_VOLUMETRIC = 2.11; // £ per m3
var RATE_SEWERAGE_VOLUMETRIC = 3.44; // £ per m3
var RATE_SEWERAGE_RETURN = 0.95; // 95% of water returns to sewer
var STANDING_CHARGE_WATER = 26.50; // Annual £
var STANDING_CHARGE_SEWERAGE = 58.20; // Annual £
// Unmetered RV Rates (Estimates)
var RV_RATE_WATER = 1.65; // £ per £RV
var RV_RATE_SEWERAGE = 3.10; // £ per £RV
var RV_STANDING_TOTAL = 110.00; // Combined fixed charges roughly
function toggleMethod() {
var method = document.querySelector('input[name="calcMethod"]:checked').value;
var meteredDiv = document.getElementById('meteredInputs');
var unmeteredDiv = document.getElementById('unmeteredInputs');
if (method === 'metered') {
meteredDiv.classList.remove('hidden');
unmeteredDiv.classList.add('hidden');
} else {
meteredDiv.classList.add('hidden');
unmeteredDiv.classList.remove('hidden');
}
}
function estimateUsage() {
var people = parseInt(document.getElementById('occupants').value);
var profile = document.getElementById('usageProfile').value;
var baseUsagePerPerson = 0;
// Cubic meters per year per person estimates
if (profile === 'low') {
baseUsagePerPerson = 42;
} else if (profile === 'medium') {
baseUsagePerPerson = 54;
} else {
baseUsagePerPerson = 68;
}
var totalEstimate = Math.round(people * baseUsagePerPerson);
document.getElementById('manualUsage').value = totalEstimate;
}
function calculateWaterBill() {
var method = document.querySelector('input[name="calcMethod"]:checked').value;
var waterCost = 0;
var sewerageCost = 0;
var standingCost = 0;
var totalCost = 0;
if (method === 'metered') {
var usage = parseFloat(document.getElementById('manualUsage').value);
if (isNaN(usage) || usage < 0) {
alert("Please enter a valid usage amount.");
return;
}
// Metered Calculations
// Water: Usage * Rate
waterCost = usage * RATE_WATER_VOLUMETRIC;
// Sewerage: Usage * 95% * Rate
sewerageCost = (usage * RATE_SEWERAGE_RETURN) * RATE_SEWERAGE_VOLUMETRIC;
// Standing Charges
standingCost = STANDING_CHARGE_WATER + STANDING_CHARGE_SEWERAGE;
} else {
var rv = parseFloat(document.getElementById('rateableValue').value);
if (isNaN(rv) || rv <= 0) {
alert("Please enter a valid Rateable Value.");
return;
}
// Unmetered Calculations
waterCost = rv * RV_RATE_WATER;
sewerageCost = rv * RV_RATE_SEWERAGE;
standingCost = RV_STANDING_TOTAL;
}
totalCost = waterCost + sewerageCost + standingCost;
// Display Results
document.getElementById('resWater').innerText = formatGBP(waterCost);
document.getElementById('resSewerage').innerText = formatGBP(sewerageCost);
document.getElementById('resStanding').innerText = formatGBP(standingCost);
document.getElementById('resTotal').innerText = formatGBP(totalCost);
// Monthly breakdown
document.getElementById('resMonthly').innerText = formatGBP(totalCost / 12);
// Show result box
document.getElementById('resultsArea').style.display = 'block';
// Smooth scroll to results
document.getElementById('resultsArea').scrollIntoView({ behavior: 'smooth' });
}
function formatGBP(num) {
return '£' + num.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
}
// Initialize estimate on load
estimateUsage();