"Headwater streams are the small swales, creeks and streams that are the origin of most rivers. These small streams join together to form larger streams and rivers or run directly into larger streams and lakes. Ohio EPA defines a headwater stream as a stream with a watershed less than or equal to 20 square miles. Many streams and drainage ways have a watershed of less than one square mile. We refer to these as 'primary headwater' streams. These streams may be home to small fish, amphibians and invertebrates." - Ohio EPA Assessing the health of primary headwater habitat streams is important. This will gauge the effects of the surrounding community on the stream. These level one effects build upon those on the greater community and can affect the overall health of the larger bodies of water they flow into.