Read the stream, item by item

Sudden colour change is often the first visible sign that something upstream has shifted.

Whether the bed shows through says how much suspended material the water carries.

Foam, sheen, and scum each point at different possible causes worth researching.

Smell is something a photograph can never capture — your nose is the sensor here.

Algal mats can signal excess nutrients and precede oxygen crashes that harm wildlife.

Stagnant water behaves differently from flowing water — it warms, stratifies, and concentrates.

Vegetated banks filter runoff; bare or concrete banks let it straight in.

Litter records how people use the site — and what washes in with rain.