We live quite close to the Aquadrome so we visit fairly regularly.
There is plenty of parking, and the lakes are surrounded by beautiful places to stop and rest, have a picnic, cycle, walk your dog, play ball and so much more.
There is so much to do here if you plan ahead, such as fishing, windsurfing, sailing waterskiing etc., but we tend to take the bikes and I wander with the dog while the others cycle on.
You can take a picnic ( there's even a no dogs picnic/play area), or you can eat at the amazing Cafe in the Park.
Since first having a tin of their chips, my kids have been hooked. They are honestly THE nicest chips anywhere EVER ;)
In fact, the cafe comes pretty close to that accolade too. They don't like waste - they encourage you to save for later what you can't eat there, and have brown takeaway boxes stacked for you do do just that.
The food is healthy but delicious, freshly baked there that day and all the ingredients are locally sourced. Hot food is made fresh to order and they have jugs of iced water for you to help yourself to.
There's plenty of outdoor seating for those with dogs, and even a quiet room if you've popped in without the kids for an hour. Bliss.
Anyway, if you follow the lakes round anti clockwise, you first come to the canal, then the fantastic play area, which even has an outdoor gym!
Keep going round the lakes and you come to the water sports club house, and then finally end up back at the cafe/car park area.
If you took a picnic, a ball, and a book, you could easily spend hours here without spending a penny. Take a slow walk with fun things for the kids, like naming the trees, or just exploring, then settle down on one of the many grassed areas to read that book,, have lunch and let the children run off some energy.
Talking of spending a penny, the toilets are clean and well stocked, and checked regularly throughout the day.
The site is also very flat, so ideal for people like me with mobility issues. There also plenty of seating around the lakes, and in the 'no dogs' area there are specially designed picnic tables on hard standing, that can accommodate wheelchairs. Another good thing about this part of the park is that it's completely fenced in, so younger ones can have the same sort of freedom their older siblings enjoy, without you having to worry about if they've gone too far.
If you're in the area then I would definitely recommend popping in - it's not far from Jn 18 of the M25
Don't just rake my word for it - their TripAdvisor 4.5/5 isn't too shabby either!