EVIDENCE LAYER GUIDE
Four flood questions that should never be collapsed into one score
A warning, a gauge reading, a catchment classification and a planning-zone intersection describe different things, at different times and geographic scales.
01 · CURRENT STATUS
Is there a current warning?
Environment Agency warning records are operational status messages with an update time and named area. They are not replaced by an old gauge reading or a historical flood outline.
Can support: whether a published warning is active in its stated area at the observation time.
Cannot establish: that every address inside or outside that area will or will not flood.
02 · OBSERVATION
What did a monitoring station record?
A station observation belongs to a named gauge, measurement type and timestamp. It can show a measured level or flow at that instrument.
Can support: a dated local observation and its recent sequence.
Cannot establish: a property-risk verdict or a forecast by itself.
03 · ENVIRONMENTAL CONTEXT
What is the catchment condition?
Catchment planning classifications and objectives preserve the classification year, water body and environmental measure.
Can support: water-body context and dated planning objectives.
Cannot establish: live flood status.
04 · SPATIAL SCREEN
Which planning flood zone intersects?
Planning Data flood-risk geometry is joined only after the place and boundary version are known. The result is a planning screen at the precision of the published geometry.
Can support: a versioned boundary intersection.
Cannot establish: survey, insurance, drainage, groundwater or emergency conclusions.
PUBLICATION RULE
Unknown states stay different.
“Not found”, “not checked”, “not published” and “not applicable” are separate outcomes. FloodingFacts publishes a place result only when identity, geometry, source date and licence checks all pass.
Current and historical separated
Old observations never become a live warning.
Precision labelled
Address, area and source-boundary results are not described as equivalent.
Corrections welcomed
Report a source or matching error.