Here's an excerpt from an email by Mark J. Crosby of the City of Madison Parks Division about their new reservation system, which applies to tennis courts.

"Madison Parks has recently moved to an online reservation system for our many athletic facilities. You can now reserve by following the ‘reserve’ links on our web page. If your reservation is for a group that is for youth athletics or tax exempt you will need to apply for those discounts by creating an account and applying on this page.  You can easily search for a general space type (soccer, backstop, ultimate, etc) or you can search for a specific park. After your initial search you can further filter spaces with things like lines, goals, lights. 

Like our shelter reservations, full payment is now due when the reservation is made. If your reservation is rained out a cancellation will be made and your payment will be refunded."