Stream Order Watersheds Watershed n A ridge of

Stream Order & Watersheds

Watershed n. A ridge of high land dividing two areas that are drained by different river systems. n The region draining into a river, river system, or other body of water.

Watershed

Stream Order

Upstream vs. Downstream

1 st order stream (1° stream)

Characteristics Steep angle / high elevation n Substrate dominated by boulders and cobbles n Narrow channel n Usually acidic (low p. H - <7) n Low biodiversity – Mostly shredders and gatherers n n High cover - usually shaded Low turbidity - clear Low temperatures High oxygen

2° stream

Characteristics n n n n Formed in a valley Less shaded Higher temperatures Less steep Wider More nutrients / higher turbidity Substrate dominated by cobbles and gravels More biodiversity – Shredders, gatherers, and collectors

3° Stream

Characteristics n n n n Also forms in a valley, where 2 or more 2 nd order streams intersect Higher temperature, less shade, wider channel More nutrients, higher turbidity Substrate dominated by gravels, sands More biodiversity, fewer of each species/type Higher p. H Slower water, less oxygen

4° and above

4 th Order and Higher Gentle slope (1 -2%) n Slow water (slack water/glides) n Finer substrate (mud to gravels) n Higher turbidity - cloudy (silts & clays) n Higher temperature n Lower oxygen n Alkaline (higher p. H - >7) n More sinuosity n Wider channel n Less tree cover – more sunlight to creek n Filtering collecters, scrapers

Point Source vs. Non-Point Source Pollution

Why is a watershed important? n What affects it? n Who owns it? n What is affected by it? n Who lives in/near it?