Gutter © atelier GROENBLAUW


  • Water: 1
  • Construction costs: 1
  • Maintenance/management: 1


Rainwater is usually drained to the rainwater sewage system, immediately disappearing from the view of the citizen. A gutter makes the water visible again in the city and is usually less expensive than realising a sewage system that separates waste water and rainwater.

A gutter is a simple form of above ground drainage for use on streets and squares. The street profile can be identical to a conventional solution with storm drains but then without the drains and with a slightly deeper gutter.

The water draining through the gutter is transported to the surface water or infiltrated into the ground
by means of an infiltration system.

A gutter must always have a slope. When developing a district without a rainwater sewage system but with open gutters, it is essential to take into account the slope necessary for the above ground rainwater system.

The slope of a gutter along a road can be realised if the road is constructed on a slope or the slope can be realised in a gutter with a slope. The maximum length of such a sloped gutter is approximately 50 meters. Otherwise the gutter will get too deep and with the usual width of 30 cm and a maximum depth of more than 5 cm the gutter cannot be cleaned by street sweepers. If the gutter follows the sloped road, the slope must be at least 0.5 cm/m.

Fluted gutters

Fluted gutters can be used in existing situations to disconnect rainwater drainage. The advantage of fluted gutters is that their use is almost unrestricted and that street profiles need not be adapted.

Fluted gutters have a minimal depth and gentle side slopes allowing cleaning by a road sweeper. They can be made from the same material as the pavement or are prefabricated. Prefab open gutters are often less aesthetically pleasing but easier to install and cheaper. It is easier to construct connections and curves with paving bricks.

Cross-section of a clinker fluted gutter © atelier GROENBLAUW
Solar City, Linz, Austria © Atelier Dreiseitl
Cross-section of a prefab fluted gutter © atelier GROENBLAUW
Prefab fluted gutter © Bleijko

Open gutters

Open gutters can drain more water due to the larger possible depth and are less dependent on natural or artificial slopes. However, they cannot be cleaned with a standard road sweeper, and they can be an obstacle or a hazard for road users (prams, bicycles, etc.). This should be considered in the design phase.

You see this type of open gutters in areas with a natural slope in the landscape. Because of this they don’t need to be flushed.

Cross-section of a open prefab gutter © atelier GROENBLAUW
Line gutter in The Hague, The Netherlands © atelier GROENBLAUW
Open gutter, Mont-Cenis, France © Atelier Dreiseitl

Covered gutters

A prefabricated gutter covered with a grate is a simple form of above ground drainage for streets and squares. The street profile can be identical to a conventional solution with storm drains but then without the drains.

The gutters can drain more water because of the greater depth and are less affected by a natural or imposed decline. Covered gutters cannot be cleaned with a regular street sweeper and must be flushed out regularly.

Because they don’t obstruct road use, covered gutters can be used in urban situations. Cyclists and pedestrians can safely cross these gutters. There are many different prefab products available on the market for covered gutters.

Cross-section of a covered prefab gutter © atelier GROENBLAUW
Bo02 Hammarby Sjöstad, Stockholm, Sweden © atelier GROENBLAUW