I thought I'd my two cents into the mix here. Got to the thread in a very odd round about through a Dailyish. So I know everybody is moved on three years later but...
We've done this. We are making an emphemeral (runs when it rains) arroyo turn into a intermittent (runs for a period of time after it rains) system, moving to perennial flow (should happen within next two years).
Slow the water down, encourage the species you want, graze correctly. That's it.
Check it out:
http://tatesmith11.wix.com/regenstewardship#!portfolio/znxwd
We've done a lot of work in our 14" precip zone in Southern Colorado and have made water come from "nowhere".
The question came up multiple times in the thread from somebody who got grey labeled, "Where does the water come from" and everybody's answers were right, water does fall from the sky! COOL!
But water also comes up from the ground. It's not just deep aquifers. There is a retention in the soil. So, as paul alluded to with his sponge metaphor, when you over soak the sponge, the water dribbles out.
By slowing the water using Hydraulic Energy Dispersion methodology (the politically correct way of saying planting water), you hydrate the sponge. You do this long enough and the sponge stays wet and dribbles. The infrastructure you built sustains the dribble through drought because soil holds a lot of water!!
Oh wait, that's where grazing comes in. As all of us know, increase the OM, increase water holding capacity. Proper vegetation management furthers the effectiveness of HED projects. Otherwise, eventually your soil profile dries up again and you have start over with 7 years of energy dispersing in order to get your sponge rehydrated and dribbling. If you have effective HED infrastructure in place, and proper veg management on top of the HED infrastructure. You can withstand any drought. Or at least bounce back quickly when the rains do come.
It's possible, our once intermittent stream now runs 8 months out of the year, 2014 it ran 5 months, in a few years it will run year round for the length of our property.
We can make creeks run again and make new ones show up. Eden is never that far away, you just have to take the first step to get there.