Seaslug,
I usually launch below where the camping is when I hit Irvine Lake. I know the water level is down and I haven't been there yet this year, so I'll have to play it by ear until I see it. The fees are $20 to get in, plus an additional $5 to launch a float tube or kayak. They have a pretty decent website with the info on it at
http://www.irvinelake.net
Hope this helps,
Perry