Stormwater Management

Stormwater Management

Storm water networks are designed to safely carry precipitation run-off flowing on the road network of a community to the discharge location which provides primary screening and is adequately dimensioned to hold or detain the flow of a significant rainfall event. In certain cases, oil separators might be considered in order to protect the receiving body should this be a stream or a wadi or any other environmentally sensitive area.

Storm water network, including pipes, gutters, swales and culverts is designed to carry storm runoff resulting from precipitation events of given duration and return period; during significant precipitation events storm networks are overflown and overland drainage takes place provided that no properties are flooded.

Key elements in a SD network are the gullies and their connections; it is often the case that pipelines can safely carry the design flow but gullies or their connection to the network can only deliver a portion of this. Our experienced engineers make sure that the proposed SD network works from the first gully to the outlet.

Modern communities tend to develop continuously and as a result not only current but also future site conditions should be considered. Covering unpaved natural areas with paved roads and residential or commercial blocks lead to an increased surface runoff coefficient and hence flow. This has to be taken into account when designing Stormwater Management systems.

Software capable of modeling the flow in the watershed in 1-D and 2-D is being used ensuring the accuracy and quality of the end result. Following this analysis hydraulics works (culverts, streams, ponds etc.) are proposed and dimensioned accordingly.

Storm water management has always been a key issue; in urbanized areas, cost effective solutions to promote public safety are of main concern whilst in rural areas harvesting precipitation has been the precious goal. Traditionally, closed pipes networks feed water bodies, main trunks or detention/retention ponds in urban developments, whilst in rural areas rarely do we get controlled precipitation harvesting conditions.

Either with social, economic or environmental benefits, Sustainable Drainage Systems (SuDS) come to bridge traditional and modern approach in storm water management. SuDS include infiltration trenches, geocells, soak-ways, porous pavement, green roofs and other works carefully designed to reduce storm peak flow, ensure better water treatment, protect receiving bodies and promote public interests.

We have significant experience in designing SuDS as per the latest international trends and guidelines.