Planning a kid-friendly wedding

My fiancé and I are in the last few months of planning our early June wedding. We wanted to keep it very casual, so we rented out a lakeside, family-friendly resort with 20 rustic cabins in my small hometown. Throwing a wedding that’s fun for kids — and easy on their parents — has been a top priority for us from the beginning. At last count, we’ll have at least 15 children in attendance: five “big” kids between ages six and 12, and at least 10 “little” kids ranging from not-yet-mobile one-year-olds to VERY active pre-schoolers. (Two of these rugrats are our adorable nieces, Simone and Eloise, ages four and 18 months — they’ll be hard at work as flower girls, wearing matching gingham sundresses. They are thrilled and so are we.)
 
So we’ll have a small circus on our hands: more than a dozen kids to keep busy and under control for a weekend. Is this guaranteed to be complete chaos? There are plenty of kid-friendly activities: swimming, canoeing, fishing, a playground, badminton and tennis courts, a sandbox, a hiking trail and a baseball diamond. For dinner we’re serving a ribs and brisket barbecue, plus mac ‘n’ cheese for the kids, on picnic tables under a big yellow-and-white-striped tent.
 
It’s the reception portion of the evening that’s a little less appropriate for kids. As bedtimes approach, the grown-ups will have to decide who gets to stay at the party and who’s stuck on kid-duty. Should we offer to arrange— and pay for — babysitting? I’m happy to hire local teenagers to provide childcare, but I wonder if parents will be comfortable handing their kids over to a complete stranger. I’m also assuming they won’t want to leave their sleeping kids alone in the cabins. (The cabins are within shouting distance of the reception tent, but it’s a little scary leaving your kid in a dark cabin in the woods!)

And then there’s my sudden anxiety about the outdoor location: the wedding site is steps from a busy road that edges around the lake. Add to that the water safety issue — there’s no lifeguard — and the worrywart side of my personality kicks into overdrive. (I blame working at a parenting magazine for this newfound ability to fret about everything bad that could happen to a kid!) Short of making all the children wear lifejackets over their outfits the entire weekend, I’m not sure there’s much we can do about this. Parents, please send advice! We want all our guests — the little ones and the grown ups — to have a great time.

How do you handle childcare and safety during weddings? What’s the best solution, and how can a bride and groom help out?