Strategic interventions to reduce flood risk for the town downstream along the River Monnow (6,000-acre catchment, ~50% arable). Focus is on increasing infiltration, slowing runoff, and storing water in the upper catchment.
50%
arable
30%
pasture
10%
woodland
5%
wetland
5%
urban
- 1Upper catchment arable fields with steep slopes
- 2Buffer strips along all watercourses
- 3Wetland/flood storage creation
- 4Soil decompaction and reduced tillage
- 5Floodplain reconnection
Riparian buffer strips
All streams and watercourses
Slows runoff, filters sediment, increases infiltration
Reforestation / Agroforestry
Steep slope arable fields (~1500 acres)
Reduces peak runoff by 20-30%, increases infiltration
Cover crops / Reduced tillage
Arable fields remaining in production (~1500 acres)
Improves soil structure, reduces surface runoff
Wetland / Flood storage ponds
Strategic tributaries upstream of town
Temporarily stores peak flows, delays downstream flooding
Soil decompaction & controlled traffic
Compacted arable fields
Increases infiltration, reduces rapid runoff
Floodplain reconnection
Areas adjacent to river prone to seasonal inundation
Allows controlled flooding, reduces downstream peak
Monitor flows and adapt interventions. Combining multiple measures gives the best reduction in flood peaks. Focus first on upstream interventions for maximum effect.