A couple friends and I are new to kayaking and are wanting to go kayak a short 2-10 mile stretch of either, but we also don't want to be out there all day. We don't fish so its just going to be a scenic/leisure paddle trip. I've read that you have to catch both of them at the right time otherwise we'll be walking and dragging a lot. So does any one know what an optimal flow rate would be for the river or creek?

I don't have any input, but I'll be interested to hear the responses. I've always wondered about Spring Creek. I've ridden my bike along side it from Jesse Jones park to Pundt Park and it looks like a great place to kayak.

I've only kayaked Spring Creek once and it was in 2010 so this may not be a lot of help. Launched at Riley Fuzzel Park and paddled 2.8 miles to Pundt Park. The trip took about an hour and 15 minutes, but the water was moving pretty fast and rapidly rising because it started raining while we were on the water. In fact, the creek rose 3' while we were on it! When we started the gauge height was 1.5' and when we got off, the gauge height was 4.5'.
At 1.5' the water was fairly clean and pretty easy to paddle with minimal portaging and lots of sandbars.
At 4.5' the water was a nasty turbid brown with lots of trash.
There has been so much development on this side of town though that these gauge readings may make little sense anymore.

I've paddled up the San Jacinto river from the 59 bridge up into spring creek, basically from where upper lake Houston starts until we got to the mouth of Cypress Creek and went up it a ways until we got to Jesse Jones park. There, Cypress creek begins to have more shallows and sandbars. Spring creek is a good paddle also with good light tackle fishing, but it does have quite a few shallow sand/gravel riffles that can be work to get by when it is really low. You can go between any of the parks but a few of them have launch or land only rules.

It's been a while since I've done it but it can be a pretty cool trip.

This has a pretty good primer on paddling Spring Creek in particular: Spring Creek Greenway

In the fall, winter, and spring before the rains hit the water can get surprisingly clear in Spring Creek due to the sand bottom. Not gin clear but more like iced tea. Plus, in late fall it's not stiflingly hot down in the creek where there's little breeze.