Seeing rainwater differently
For a long time, rainwater was treated as waste to be piped away as fast as possible. As more and more ground is sealed, this logic is reaching its limits: overloaded networks during storms, flood risk downstream, less groundwater recharge, urban heat islands. For FINC Solutions, stormwater management is therefore an urban design issue in its own right, not just a pipe-sizing exercise.
An eco-district does the opposite: it treats stormwater as a resource and as part of the landscape. The aim is to manage it as close as possible to where it falls, reducing the volumes discharged and making use of what can be used.
This ambition is set at masterplan stage. Once roads, buildings and networks are fixed, there is very little room left for manoeuvre.
Understand the site before drawing
Every strategy starts with an assessment: topography and flow paths, soil type and infiltration capacity, groundwater depth, possible contamination, local rainfall patterns and available outfalls.
These data directly shape the project. Permeable soil favours infiltration; clay or contaminated soil points towards attenuation and reuse. Topography shows where water will naturally flow, and therefore where to locate the management features.
- Topographic surveys and catchment analysis
- Soil permeability tests
- Groundwater study and any contamination constraints
- Identification of outfalls and local discharge requirements
Infiltrate, retain, slow down: nature-based solutions
Swales, wide and shallow vegetated channels, collect and infiltrate runoff from roads. Rain gardens play the same role at the scale of a plot or a small square. Green roofs hold back part of the rainfall and return some of it to the air through evapotranspiration.
Permeable surfaces, such as grass-jointed paving, grassed parking bays and pavements with a reservoir sub-base, reduce sealed areas without giving up their use.
These open-air features have a decisive advantage: they are visible, so easier to inspect and maintain than buried structures. They also bring biodiversity and summer cooling.
Harvesting and reusing rainwater
Harvesting roof water can cover part of the demand for non-potable water: irrigating green spaces, cleaning public areas and, where local regulations allow, certain technical or sanitary uses.
Tank sizing balances collection area, local rainfall and real demand. An oversized tank is expensive and often half-empty; an undersized one overflows at every rainfall event.
A reuse network also requires strict separation from the drinking-water supply, clear labelling and a maintenance plan covering filters, pumps and quality checks.
Simple measures improve the quality of stored water: filtration at the tank inlet, a first-flush diverter for the initial, more particle-laden runoff, and a tank protected from light to limit algae growth.
Integrating water into the urban and landscape design
The best projects do not overlay a drainage system on an urban plan: they design both together. A swale becomes a planted walkway, a detention basin a garden that floods a few days a year, a square a temporary storage area during heavy rain.
Exceptional storms must also be considered, as they will always exceed the capacity of everyday features. The design must show where water will then flow without causing damage: surface flow paths, public spaces that flood in a controlled way, raised building thresholds. Planning for exceedance is an integral part of the district’s resilience.
At FINC, this approach translates into joint work between engineers, architects, landscape designers and future managers. They will be responsible for maintenance, and involving them at design stage ensures features that are simple to run.
From Quebec to Morocco and Africa: the same water, different stakes
As a Canadian consultancy present in Morocco and Africa, FINC Solutions designs stormwater management in very contrasting hydrological settings.
In Quebec, the aim is often to relieve combined sewers overloaded during storms and to deal with snowmelt and frost, which shape the choice and sizing of infiltration works.
In Morocco and many African countries, water stress turns every cubic metre into a resource: harvesting and storing rainwater for irrigation or some non-potable uses, recharging aquifers and guarding against flash floods during intense rainfall become priorities. Nature-based solutions adapt well, provided that drought-tolerant plants are chosen and the works are designed to be easy to maintain.
How FINC Solutions contributes
We designed a sustainable eco-district combining passive buildings, green spaces and a system for harvesting and reusing rainwater for irrigation and technical uses.
From soil investigation to sizing the features, through landscape integration and dialogue with network operators, FINC’s teams support developers and local authorities. If you are preparing a development project, we can look together at your site’s potential.
Frequently asked questions
Is infiltration possible on every site?
No. It depends on soil permeability, groundwater depth and the absence of contamination. Soil tests confirm it; where infiltration is not possible, attenuation and reuse are preferred.
What can harvested rainwater be used for?
Irrigation and cleaning are the most common uses. Other uses, especially inside buildings, depend on local regulations and require specific health precautions.
Do swales and rain gardens need a lot of maintenance?
Regular but simple maintenance: mowing, litter removal and checking inflow points. It is similar to looking after green spaces and should be planned with the future manager.
