Tile Kiln Farm, Essex

Services offered

• SuDS Surface Water Drainage Strategy
• Flood Risk Assessment

The brief

Civilistix  Consulting Engineers were appointed to undertake a combined Flood Risk  & Drainage Strategy to support the accommodation of 36,000m3 of  imported fill material at an existing 13.40ha quarry site, raising  existing levels by up to 3.0m.

What we did

Our drainage strategy overcome two principle problems; preventing  existing drainage pathways becoming blocked by ground raising proposals  and attenuating the additional runoff caused by the fill material.

For the former, we provided a ~400m dry swale around the ground raising  extends to intercept existing runoff and convey it to existing ditches  (to mimic the pre-developed state).

For the latter, we proposed a ~1150m3 attenuation pond to attenuate  additional runoff at the 1 in 1 year greenfield runoff for all events up  to and including the 100yr+40%cc event creating a betterment when  compared to the predeveloped site. Dry swales where used to convey and  treat runoff.

The measures we implemented ensured greenfield runoff rates and volumes were never  exceeded and the necessary level of surface water treatment provided.