Water has always been central to Louvain-la-Neuve’s urban planning. The artificial lake is the most obvious example, but that’s just the tip of the iceberg.
The Louvain water cycle
In a typical urban area, 90% of rainwater becomes ‘urban run-off’ – rainwater whose drainage is rerouted by urbanisation and is thus a major source of flooding and water pollution. In Louvain-la-Neuve, urban run-off is only 37%, a Belgian best made possible by the innovative thinking of the city’s planners in the 1960s. Louvain-la-Neuve is a town that was raised out of fields in the valley of the Dyle, a major tributary of the Scheldt. The town’s design minimises impact on the water cycle in three ways.
Roofs, gardens, pavements, car parks and green spaces were designed to allow a maximum of rainwater to drain underground and thus replenish the groundwater table whose volume is 240 times that of the Lake Louvain-la-Neuve.
Thanks to the semi-permeability of its bed, the lake serves as a storm basin for rainwater run-off. It’s also central to the life of the town, a place of recreation and relaxation, and is routinely emptied, cleaned, maintained and refilled to protect and preserve its biodiversity.
Another of the town’s distinctive features is its dual drainage network, which efficiently manages waste water by routing it to the Basse-Wavre treatment plant and discharging into the Dyle, and separately routes rainwater run-off to the lake.
Via four catchments, UCL collects between 200,000 and 500,000 cubic metres of water each year for industrial uses, including cooling UCL’s cyclotron and partially supplying academic buildings. This water is distributed via the Lavoisier building, where it is purified by both carbon filtration, which eliminates potential organic contaminants, and chlorination, which eliminates bacteria.
These catchments are of course part of a system and serve a cycle. Efficient run-off management allows for infiltration of four times the lake’s volume and thus maintains the natural balance of the groundwater table.
From water table to tap, water quality is frequently monitored. Infiltration water is monitored using a 12-metre well.
Rainwater is also analysed, using the Biéreau plateau meteorological park, where rain gauges, agro-meteorological stations and a lysimeter (which measures evapotranspiration) are used to analyse rainwater in fine detail.
Louvain-la-Neuve’s dual drainage network is unique in Belgium. It allows for efficient, environmentally responsible waste water management and for separate transport of run-off to the lake.
Balanced, sensible water management also depends on how it’s used. Raising awareness throughout the entire university community is essential. Organisations such as Univers Santé play a crucial role in disseminating information and giving advice on water use.
Since 2013, UCL has collaborated with the Festival International du Film Eau et Climat (‘International Water and Climate Film Festival’). Each year, the festival raises student and general public awareness of water and climate change issues through films selected by audiovisual professionals and screened to full houses at Louvain-la-Neuve’s Cinéscope. The moving image is used to raise awareness, enlighten and call for action that protects water. The event also sparks dialogue between the worlds of research and civil society.