Warm, dry sunny weather for over 10 days. Flow from upstream to bridge was very slow, sides of water had brown algae/sludge floating on surface. Large tree trunk and wooden pallet, (with large nest possibly swan) were straddled across just in front of bridge, not sure if deliberately placed or accidental. That seemed to slow the flow. Downstream beyond the bridge the water was flowing faster, but at my sampling point slow enough for tadpoles to be seen swimming around, and what may have been a cased caddis crawling along some submerged wood.