Water is important for the flora and fauna, local climate, soil and humidity in the national park.
Streaming, undisturbed watercourses are particularly valuable. The watercourses in the national park have a rich wildlife and plant life. Many different species of fish and benthic fauna live here. Several of them are sensitive to pollution and acidification which confirms the value of protecting the area. The White-throated Dipper and the Grey Wagtail are characteristic birds in the area.
Several small streams flow along the ravines. Ponds and marshes provide valuable variation in the area and contribute to the significant biodiversity. Odensjön is the national parks’s only natural lake, both Härsnäsdammarna and Skärdammen are landscaped.