Hey whats going on. I live in Ashburn, 20-30 min from chantilly. There are some good lakes in South Riding which is next door to you. One is off of crossfield drive and tall cedars parkway which is really good. Lake Fairfax isn't too far and beaver dam reservoir is good too. In ashburn there are many lakes as well. There are about 3 -4 off Ashburn village drive. Hope this helps.