I know this is an old question, but if it can help in the future:
You may want to check https://storetraffic.com, whom I work for :)
We have the PEARL People Counter sensor which is battery operated, uses Wi-Fi, bidirectional and "stick-to-install".
There is also an API available with our paid plans.
LoRaWAN is one of the best technologies for collecting data from water meters. This is because LoRaWAN networks operate in sub gigaherz bands and apply low (~14dBm) TX power. This enables long (even 8-10 years) battery life if the meters report their counter only one or 2 times a day.
However, bridging 10-20km distance for water meters is not realistic at ...