The government should take it upon itself to build specialty parks (skateboarding parks, rollerblading parks, model rocket parks, remote/radio control airplane parks, model car racing parks, etc.) on public lands to satisfy the desires of people to do such things and even to increase the capacity of the local recreational infrastructures to allow and encourage more people to take up such fun hobbies.
Several of these places could serve dual purposes so that multiple activities could be accommodated at the same time, such as skateboarding and rollerblading. Other activities could be accommodated in the same space but at different times. For example, remote controlled airplanes could be flown every Monday, Wednesday, Friday and Sunday, while model rockets could be flown every Tuesday, Thursday, and Saturday.
Some parks could also be placed in small nooks and crannies even around very built up landscapes. For example, skate parks with ramps and all relevant equipment could be placed at the bottom of concrete lined storm drain channels. Dry storm drains and other river beds could be used for many other recreational purposes, like playgrounds, bicycle and pedestrian paths, tennis, basketball, and other sport courts, off-road vehicles, farmer’s markets and other business or social events, and many other purposes. Of course, during times when rain is threatened, or whenever the storm drain is expected to significantly increase its flow, such parks would be closed and the ramps and other equipment would be permanently hooked up to cables connected to some kinds of winch lifting system so that the equipment is lifted and suspended clear above the channel until the threat of rain or channel flooding has passed.
The government should bear no liability for injuries due to the use or misuse of such equipment unless those injuries were due to construction failures.
Shooting ranges could also be a type of specialty park that can be located within highly developed areas by locating them within storm channels. There are already practically two bullet proof side walls that exist, it would only be a matter of enclosing both remaining ends and the top. The top could be a permanent roof structure that would not ever need to be moved. The two ends of the enclosed room could be built of bullet proof walls that could be raised when ever needed so the flood control channel can serve its purpose. Schedules could be enforced by personnel that after every 45 minutes of shooting, 15 minutes would be reserved to place, checkup, and remove targets and debris.
Race tracks and off-road courses for full sized automobiles should also be placed throughout urban and suburban areas. Long straight race tracks and drag strips could possibly be made within storm drain channels, while shorter ones could probably be scheduled for use on local airport runways during one or two days a week or during predictable slow air traffic periods such as midnight to 6 AM.
Certain segments of beach shorelines should also be reserved for wave surfing.
Fees could be charged for the use of such park facilities so that, ideally, all the money spent on construction and maintenance could be recovered from the users. Several such parks may need to have personnel there to supervise the activities (especially the shooting ranges). Video cameras could be installed to monitor and record all activities so that any illegal activities (especially vandalism) would be recorded and the perpetrators caught and made to pay.