The Marianna dam once provided water supply from Tenmile Creek to the coal mines, and later to Marianna Borough, but it now stands idle. Tenmile Creek is a biodiversity gem in southwestern Pennsylvania, hosting sportfish like walleye, muskellunge, and smallmouth bass, and also important small species such as darters that host freshwater mussels, which in turn naturally filter and purify the water. A recent survey by PA Fish & Boat Commission found that the dam is a barrier that prohibits these fish from accessing the smaller tributaries upstream that support their lifecycle, and this causes a cascade effect that reduces fish populations and impacts water quality. The dam is a public safety hazard where at least one person has drowned in recent years. The dam is also causing Tenmile Creek's current to eat away at the foundation of a section of state route 20/20. Removing Marianna Dam will allow for the installation of stream structures that will redirect the current away from the road embankment and reduce the potential for landslides there. When the dam is removed, a safety hazard will be gone and native fish will once again flourish. When that happens, Ten Mile Creek can become an important fishing location and a community asset for citizens in Marianna and West Bethlehem Township.