If you ask kommunen, then they might give you the key for your meter. Myself and couple of other people here in Sweden have received our keys from our kommuns. The key is only to prevent you from listening to other people's water meters, so there is no harm in you having the key to your own meter.
Then you can use for example: https://github.com/weetmuts/wmbusmeters
with a suitable USB dongle.
This program then receives the readings and updates a file with json data whenever a new wireless message arrives (every 15 seconds or so). You can then feed that data into the home automation system of your choice.
The json data looks like this:
{media:"cold water",
meter:"multical21","name":"MyTapWater","id":"12345678",
"total_m3":6.388,"target_m3":6.377,
"current_status":"DRY","time_dry":"22-31 days",
"time_reversed":"","time_leaking":"","time_bursting":"","timestamp":"2018-02-08T09:07:22Z"}