The area is mostly grass though, under some areas where the trees have grown in pretty dense, the ground is covered in dirt. For a little while after significant rainfalls, these areas of dirt can devolve into a muddy mess pretty quickly.
These trees are very beneficial, especially in the summer months, as they are responsible for providing a lot of shade to the area to protect you from the beating sun. There is water access at this dog park so that you don't need to bring your water for you and your canine. Do not forget a bowl.
This park does have a fence that surrounds the perimeter so even the most prominent runners cannot escape. The fence does separate the Reservoir Dogs Park into different sections for large and for small canines, though they can meet at the fence line and stare at each other if they so wish.
The Reservoir Dogs Park is provided for and maintained by volunteers. Due to this the park occasionally gets a bit overgrown, and maintenance can be lacking. Due to the forest biome, there have been complaints of bugs, fleas, and ticks in the area growing a bit rampant so you may want to bring some bug spray.
Out of the three major dog parks in the area, there are some reasons why you should consider coming to the Reservoir Dogs Park. However, if a well maintained and clean park is what you value most, you may be better off looking elsewhere.