This information was part of a press release today from Howard County Government:
The Worthington Dog Park will re-open on Wednesday, May 13th for members that are pre-registered. Members can pre-register beginning Monday at 8:00 a.m. To register for a 45-minute slot, dog owners can visit activenet or call 410-313-7275 (Monday-Friday, 8am-4:30pm). Upon arrival, members must show the attendant a print or digital copy of their confirmation receipt. There will be five available slots for the small dog park and eight available slots for the large dog park each hour. Each handler may sign up a maximum of two dogs per slot.
Here is the location of the Worthington Dog Park in Ellicott City: