swimming in the canal

I mentioned earlier traveling to CA to see my brother and his wife when I was 16. We took a little weekend trip to the Sierra Mountains & Yosemite Natinal Park. Wow! I didn't know you could see so many spectacular waterfalls in one place. Some seemed so high that the water never made it all the way down. It kind of drifted off with the wind.
Another time - I'm not sure where we were at, but I think near Modesto maybe. It was a hot day and Bro said lets go swimming. We drove to this man made looking very straight creek. I jumped in and was shocked at how cold the water was. It was explained to me that this was actually a irrigation canal where snow melt from the mountains flowed through to water crops in the valley below. At that time "the valley" as they called it, produced a very large percentage of our nations fruits and vegetables. We stayed a good while, enjoyed the water, the sun and each other.
I was told that sometimes people would tie a rope onto a car bumper and ski in the canal. I didn't see any of that but I'm sure it would have been a sight.