Glad you like it 
This was one of my first Arduino projects. It turned out better than expected.
I have thought about making a version 2 with a web interface, maybe use a Raspberry Pi Zero as a webserver and a Arduino as slave.
It would be nice to be able to view graphs on temperature etc. and configure the irrigation system with a phone or computer.
But because the current solution "just works" (and have worked for years) I have not started yet.
A touch screen would also be nice.
What do the buttons do? What are the menus like?
It is just simple text menus.
Like enabling/disabling valves, set schedules (days and time).
Have any data from the sensors?
No just max/min (last 24 hours) and current value.
Actually I have tested to log values each 10 minutues with a ESP8266 and save the data on ThinkSpeak just to check temperatur and humidity.
Perhaps a cool graph or two?
I log a lot of things at home
Weather: ESP8266 posts data every 10 minuter to ThinkSpeak. Both indoor and outdoor.
Heat/Pumps and storage tank: DIY VBUS interface that decodes my solar computer (brand Resol), decoder written in C on a Raspberry Pi Zero.
Energymeter: Arduino measures pulses with a photo transistor. History data is send over I2C to the Raspberry Pi Zero.
There's some stuff getting overlooked as well, I believe there's a water level sensor in that bin?
Yes I have a water level to protect the pump, it happens that I forget to refill the bin.
What pump are you using? 12v could be anything!
Yes it is 12V.
This one: Dränkbar pentrypump, 12 V - Biltema.se
Only ~ 14$, have worked for several years now.
What happens if the water level gets low? What is sourcing the water, is it from the roof?
I have to fill the 200L bin manually. But 200L of water is enough for several weeks.
Here is somethink that i could improve. A mail message or SMS could be send.