SUDS: Introduction

Sustainable Urban Drainage

Since its begining, HIDROSTANK has combined the injection of its innovative modular reinforced polypropylene access chambers, with the design, manufacture, supply and installation of various hydraulic equipment for rainwater and sewage networks (storm tanks, spillways).

The result of this double experience, and above all, an analysis of the needs of the sector, made HIDROSTANK offer solutions that allow, wherever possible, a sustainable management of urban drainage.

Hidrostank bet born of the conviction that the solution to the problems caused by the urban process should be mixed: on the one hand by conducting part of the water to conventional treatment plants, combined on the other hand, with infiltration/retention at source using sustainable urban drainage systems (SUDS), which enable better water quality, prevent flooding, and allow aquifer recharge and urban development in areas with saturated downs.


The urban process cause constantly serious flooding problems and degradation of natural waterways (rivers, sailing, etc..). The rise of the impermeable areas and a deteriorating drainage system lead to a serious deficiency in the management of runoff, both in volume and quality.

Conventional drainage systems, based on pipe networks, aim to move downstream the stormwater runoff captured in urbanized areas. Their abuse can cause serious flooding problems, but also pollution on the natural channels because of the discharge of water that carries high concentrations of diffuse pollution (heavy metals, oils, etc…).


The sustainable urban drainage systems (SUDS) are a set of advanced technical solutions for stormwater management, contributing to a more sustainable urban development, as they take into account not only the problem of the quantity of water, but also its quality and amenity issues (biodiversity, landscape potential, enabling natural habitats, reuse of water for other uses).

These systems are more sustainable than traditional drainage methods because they:

  • Manage runoff volumes and flow rates (reducing the impact of urbanisation on flooding).
  • Protect or enhance water quality, natural flow regimes in watercourses, natural groundwater recharge, underground rivers…Enable the evapotranspiration from vegetation and surface water.
  • Generate social and landscape value, create better places to live, work and play.
  • Provide a habitat for wildlife in urban watercourses.
  • Enable the use of rainwater for other uses (irrigation, street cleaning…).
  • SuDS also allow new developments in areas where existing sewerage systems are close to full capacity.

It is recommended a runoff control at origin: By the dealing with runoff at source the volume of water and the potential amount of contamination is less, and allow infiltration of the surface water to the ground. Only if the water cannot be managed on site (too much runoff or bad quality to infiltrate) should be slowly conveyed elsewhere. As last option, runoff could be conveyed through pipes and discharged to a wetland or detention .


The variety of SUDS could be classified as:

  • Source control: Green roofs, Permeable pavings…
  • Swales & conveyance channels.
  • Filtration: Filter strips, Filter trenches, Bioretention area…
  • Infiltration: Soakaways, Infiltration trenches, Infiltration basins
  • Retention & detention: Detention basins, Retention ponds, Geocellular drainage.
  • Wetlands.

The geo-structures or geocellular modular systems allow the above functions easily and with high integrability in current urban design (of high building density). They can be used in the source or the runoff can be conveyed to the area of infiltration / retention by a drainage pipe or channel. The modular nature of geocellular systems means that they can be tailored to suit the specific requirements of any site.