Small Normandy chalk stream flowing toward the Seine estuary where spring water keeps temperature stable and trout selective. Wild brown trout and grayling. Classic patterns: small olives and ephemeralids (16–18), sedges (14–16) evening. Pocket water where reading current and understanding trout lies matters more than distance casting. Some access restricted; check AAPPMA.
In chalk-spring and karst trout systems, generally stable temperatures broaden olive and other mayfly activity from early spring into autumn, with strong evening caddis, steady subsurface scuds and buzzers where clear groundwater and weedbeds develop, and terrestrials from meadow and woodland banks rounding out the food calendar, depending on how fast each river drops and clears after rain.
- Chalk