We’re going a different direction on these.
We already had a $29 Leeo acoustic sensor so we would get notifications on our phones if any of the nonnetworked smoke alarms went off. This uses Wi-Fi and has its own IFTTT channel/service.
Since we got it, they have added the ability to recognize some standard leak detector alerts. ( it’s now available for android as well.)
https://www.leeo.com/introducing-water-alarm-monitoring-smart-alert/
If you just want spot alarms, the throwaway Honeywell RWD14 work with Leeo, and they usually sell in a four pack for $16.
Or there are other inexpensive nonnetworked water alarms which are reusable that work with Leeo.
So Leeo hears the alarm and then sends you the notification. So in our case we have one acoustic sensor (the Leeo) covering about 12 different nonnetworked sensors in the house, some for fire, some for water.
Anyway, the Leeo does need to have both power and internet available to work, but so does SmartThings, and I found this much more cost-effective than buying individual networked sensors for each location. 