I'm no where near as far along in my water management as I would like, but I do have a few things going, and look forward to learning and doing more. To absorb fall-spring rainfall without turning my garden into a mud puddle, I have my hugels perpendicular to contour, so the water doesn't pool up in the paths. Since the hugels are made with a lot of buried
wood, the wood soaks up the water that falls on the hugels (if I had some of the wood buried, they'd soak up some ground moisture, but I didn't get around to that with most of my hugels).
I also have a wetlands that I'm restoring (the previous owner dug ditches through it and put in culverts:
https://permies.com/t/49656/grey-water/Wetlands-Duck-Poop-Previous-Owners) to hold more water and to grow edibles like cattails, service berry and arrowhead. I plan on burring some wood deep in the wetland to hold more moisture there for a longer time. Since there are all these ditches, which are also connected to my house, the water runs off most of my
land and gets stored in the wetlands.
One important thing to note is that, if you don't already have designated wetlands, you might want to avoid digging ponds and making them unless you want them to be turned into "protected wetlands" that you can't do much on. Large
pond digging also requires permits. 1/3 of my property is government protected wetlands... though obviously the previous owner did not protect them too well. At this point, I'm just trying to make them look more natural so I don't get fined for them having been destroyed.
Another thing I have is rainwater catchment, though it is lamentably pretty small. I have a 55 gallon drum that is attached to one of my gutters on my 1500 sqft metal roof. This actually fills up pretty fast, and even in our very dry summer, I was able to take 5 gallons a day to water my ducks with the rain barrel only going dry once.
I think a main thing to remember about water catchment her in the Pacific Northwest, and elsewhere too, is the importance of storing water in the ground and letting it peculate down to the aquifers. Having our aquifers and
wells dry up is no good, and maintaining wetlands so that the water has a chance to peculate down is very important...though also annoying when legally you're not supposed to do anything with it other than passive recreation around the wetlands.