Theory 94/Urban & Built Environment/Stormwater
Runoff Tips on Imperviousness
The claim
Stormwater retention fails above a threshold in impervious fraction, because infiltration capacity is lost faster than storage is added.
01Mechanism
Runoff rises nonlinearly with imperviousness; green infrastructure can compensate only below the threshold where the remaining pervious area still functions.
02Prediction
Retention failure should track impervious fraction.
03Refutation
Failure tracking rainfall intensity would remove imperviousness.