What mode of transportation is preferred from Badaling to Guanting Reservoir?

Hi, I am planning to visit Beijing in November with my family. I want to visit Guanting Reservoir from Badaling and got following related questions:
1. Can I take a Taxi from Badaling Railway Station to Guanting reservoir?
2. How much is the Taxi fare?
3. Will I be able to get a Taxi back from Guanting Reservoir to Badaling railway station at around 4:00 pm?
4. Is there any boating facility in Guanting reservoir? how much do they charge for boat ride, if there is any?

Thanks