WebTable 6- Greenfield Runoff Rates*- FEH Statistical Method Return Period Peak flow (m3/s) l/s/ha 1 in 2 0.14 2.7 1 in 30 0.37 7.2 1 in 100 0.54 10.6 * Based on a BFIHOST value of 0.227 FEH Revitalised Flood Hydrograph (ReFH) Methodology The ReFH method was developed to address several problems in the FEH rainfall-runoff method, which was ... Webthe greenfield runoff rate from the site for the 1 in 1 year event, or 2 litres per second per hectare (l/s/ha); And b) for the 1 in 100 year event, must not be greater than either: the …
Surface water management and SuDS HR Wallingford
WebFor greenfield developments, the peak runoff rate from the development to any highway drain, sewer or surface water body for the 1 in 1 year rainfall event and the 1 in 100 year rainfall event should never exceed the peak greenfield runoff rate for the same event. S3 For developments which were previously developed, the peak runoff rate from the WebThe greenfield runoff volume is calculated using the 1:100 year 6 hour event. This volume is the amount that can be discharged at the 1:100 year greenfield runoff rate. The additional runoff volume should be discharged from the … shantell obrien
28th July 2010 FLOODING & DRAINAGE - North Lanarkshire
WebSep 8, 2024 · Region - Select between England and Wales or Scotland and Ireland from the drop-down list. M5-60 (mm) - T he rainfall depth (specified in mm) for a 60 minute … WebGreenfield Runoff Calculation Methods The two runoff calculation methods designed to calculate small greenfield runoff rates are IH 124 and ADAS 345. These methods have both been calibrated against data from smaller rural catchments, so both can be suitable for runoff calculations for greenfield sites. http://ftp2.ciwem.org/2024/2024%20Spring/Paper%208%20VRS%20Probabilistic%20SuDS%20-%20Stovin%20V..pdf shantell moore erath la