Kevfra, I lived in the Sacramento, Rocklin, Roseville area from 1966 until 2004 and always had at least one boat. We kept a boat slip/boat at Folsom Lake most of that time. All of the lakes in N. Ca. are in some manner or other flood control lakes, and thus are drawn down in late fall to hold flood water until the next spring. But, Oroville is one beautiful lake to use, and basically the largest and it has several marinas. There are more available close to GV but they all suffer from the fatal flood control issues. The delta is always going to have water as it is a sea level. I have kept a boat in the delta from the early 70s through the 2004. There is much more to do in the delta, and we tried marinas close to Sacramento all the way down to Stockton and west to Benecia. There were several of us with boats and eventually we came to the conclusion the best location for us was Village West, as we could literally fly down I-5 and be there with 75 minutes, barring accidents. We had tried others on the east side of the delta, but we found out it took some additonal time to get to the heart of the delta, but closer to Stockton you had everything including West Marine, etc and real grocery stores. From there it was not much of a long boat ride, and at the cost of gas that can become a significant factor. Now, that is coming from the Sacramento area. Coming from the bay area that is another issue. Also, berthing in Sacramento is limited, but in addition it gets real old going to old Sac and the American River. I tried that too, but only from years of experience can I tell you that keeping the boats in Village West was the best overall solution.
So, if you like a consistent boating environment, go to the delta, or keep another boat on one of the many lakes surrounding grass valley. IN the spring those lakes are primo.