Controllable water valves?

Depends on where you live. Not open source but Ikea has one.

https://www.ikea.com/se/sv/p/knycklan-elektronisk-diskmaskinsavstaengning-20425724/

I built my own with an esp32 and esphome.

Esp32 runs a relay board which switches the 24v to my sprinkler valves.

Rachio is supposed to have a local API coming soon. The Smart Hose hardware is great quality and I’m happy with their app in the meantime. Waiting to see how they open the integration before I commit heavily.

I have one of these with normal sprinkler system valves. opensprinkler.com/. Works great with home assistant.

I made my own that used irrigation valves with a Zooz Zwave dry relay, with Home Assistant to control it. It was a giant pain to find and get everything hooked up right but afterwards it works well.

I’ve since found some zigbee-based irrigation valves in AliExpress that I’ll try out this summer. I think they’re about the same price as what I built per valve (considering all the parts and the time needed). I haven’t had a chance to try them yet as I got them at the end of last summer but they worked well in testing.

I used to have a 4 zone home-brew solution with hoses hooked up to a home-made manifold with valves. It worked really well, but I was never confident in the durability/longevity of it. It was on a side of my house that I never looked at, and I just knew one day it was going to break and waste a bunch of water. It never did, though, and we ended up moving and I threw the contraption away.

Anyway, what I did was used irrigation valves, with a dry contact relay for each one.

Most irrigation valves run on 24v AC (not DC), so you need to buy a separate power supply for them. The dry contact relays that you use is up to you. I used a Sonoff 4CH Pro R3 (flashed with Tasmota, of course!).

The hardest part for me was the plumbing. These valves come in various sizes (3/4", 1", etc) and are either threaded or not. I ended up using non-threaded with PVC cement. Once you glue everything together it's permanent. Then I had to figure out how to connect a hose, which of course has specific threads for hoses. The valves are designed to be buried in an irrigation box, but mine were above ground exposed to the hot sun, elements, etc. Like I said, I wasn't confident in the longevity, but it did work well.

Something like this: https://a.aliexpress.com/_EyxaOkZ