"They work well together and they're very supportive of each other. The core group of swimmers probably trains three times a week. The success that they've been getting is through their attitude and their efforts at training.
"We've mixed things up a little bit more in the past six months. We've looked at what we're doing with those younger kids and made the training a little bit more connected to racing - more emphasis on race skills and doing the basics really well."
Johnson says there are many benefits for children involved in swimming.
"Some people see swimming as an individual sport because when they race, typically they have their own lane. But at the end of the day if you want to be successful you need that strong team behind you. I think we're really good on the coach-parent-athlete relationship.
"For the younger kids, we always say it's about fun, friendship and fitness. As they get older, the words we use are teamwork, commitment and excellence. Those are our key values.
"Swimming is a healthy sport and I think what it gives them is that discipline and that connection between effort and results. It's also a foundation sport for other sports - we have a lot of kids who will do water polo, Xterra or triathlon. It's a foundation activity that can open doors for all sorts of water-based sports."