After 16 months in our new house in the Alpilles we have just got our first water bill. We have two meters - one for the domestic supply - that was below €500 so ok ish but the one for the garden supply was close to €20,000…….. .!!! We have an average sized garden (less than 2,000m) with an average sized pool. I still need to investigate but wanted to ask if anyone can shed any light on any possible explanation please.
Thanks
Are you sure you haven’t muddled up the way with commas and full stops for numbers ? If not … 
Did you take a picture of the meter readings when you moved in?
And is the bill for projected water usage or actual
Do you have a cover on your pool? And do you use a watering system that comes from the network rather than collected water? And have you checked that there isn’t a leak on that circuit?
€500 seems high too? How much is your water per cubic metre? That’s roughly what we pay for our house and a 6 person gîte.
Once you’ve sorted out what’s gone wrong with your water bills (I’m intrigued you have two meters). I strongly recommend you ween yourself off a mains water supply for your garden and install as many water butts as you can. Even better, install an underground water tank and take the rain off the roof into that.
I wonder if you have a local farmer who has been availing himself of your water system?
How much..?!? 
I just checked and the average price in France is 4.30 € per m³. Twenty grand is therefore roughly 5,000m³. I think an average pool only contains somewhere between 75m³ - 80m³ of water.
I’d be straight on the phone to your water company in the morning. Hopefully it’s just an error when recording the meter reading.
This is a fantastic solution if you can do it. When I lived in Turks & Caicos both my house and my brother’s house next door had a rainwater collection system that fed into a big tank under his house.
Mains water was not available in the area we lived, so the alternative would have been to buy water delivered by tanker. The rainwater system worked so well that we were able to use it for all our water needs, and I don’t recall ever needing to buy any water, even in the driest of years.
That was a purpose designed system built into the house of course, but it shows what’s possible I think.
Or look into digging a well (forage) - we use this for all our gardening needs.
That happened a lot where I lived previously and remote holiday homes or even inhabited but out at work places had their supply tapped by nearby unscrupulous agriculteurs. We always had a tap that you removed the turning piece on the top to stop anyone using the back outside tap
We had exactly the same system when I lived in Bermuda. I vividly remember the water tankers making deliveries during dry spells.
Thanks all. By way of update having spoken to the water company - bill now at least 8,000 less as was being charged for waste water rather than garden water. Also bill for 1.5 years. Still overall cost is huge, next step looking for leaks in the irrigation system,
In our area the cost of disposing of the waste water is always more than the price of the clean water supplied in the first place. So if they were erroneously charging for waste water I would have expected the bill to reduce by more than half. Obviously different areas have different prices but ours is €1.225 TTC per cubic metre for supply and €1.914 TTC per cubic metre for disposing of the waste.
Our French neighbours think we are profligate with water due to the amount of laundry they see on the line plus the use of a pressure washer on walls and paved areas. There are just two of us and even with watering our admittedly very small garden our bill comes to around €500 a year with a steady year on year consumption rate of a smidgeon either side of 110 cubic metres.
A bill of €8,000 pa for garden water is huge. Makes me wonder what you are growing that could possibly need so much. Alternatively, is there perhaps a massive Abonnement for having an Agricultural / Horticultural supply in addition to the house supply. Seems like there must be a serious problem with the irrigation system, either with leaks or the timer is broken and it is running virtually continuously.
Ours comes to €3.139 TTC for a cubic metre so there must be quite a large price difference between the two ends of the spectrum. On top of that is the Abonnement which comes to €152.28 per year and then some piddling little charges for this, that, and the other, come to €49 a year all taken together.
I’ve always had a big dislike of using potable water for such tasks so rarely used the small mains pressure Karcher that I bought years ago.
I’ve now got a battery powered* Sthil (other brands are available) pressure washer that can be used with an unpressurised water source, such as a bucket that one fills from a rain water butt. I can now clean off the slippery surface on our sizeable amount of decking without guilt or expense.
*I already had a pair of the right batteries for use in my chainsaw & strimmer.
Sorry, but 110m3 for 2 people then they are right! As I said above that’s what we use for our house a 6 person gîte (used 25-30 weeks a year and generating a mountain of washing). Do you have a lot of visitors?
We average around 60m3 for the two of us and that includes a little bit of pool top up during the summer.
We (two of us humans) consume 75m3, and 6 thirsty cows (who we supply with water to help our elderly farmer neighbour) drink an additional 25m3…
Not really. Perhaps it’s the dishwasher that does it. I’m in the process of installing an extra 900 litres of rainwater capacity so that should cut the mains usage down a bit.
Or a dripping tap, or toilet that continuously dribbles. Either can use 5-10 cubic metres a year. As can leaving the tap running excessively when you brush your teeth or wash up. Tiny changes can make big difference.
And the dogs?
Pretty unlikely. We run our dishwasher every night & only used 65m³ in the most recent 12 month period.
We’re a household of two, with increased occupation (up to 12 people) for approx. two weeks in the summer, & some extras at the turn of the year too. We only take showers (there is, deliberately, no bath) & all irrigation this past year has been rainwater only.
Our two seem to prefer our well water, but you’re right they must consume some mains water.