( The problem
Three kinds of water,
one change in the record.
Surge
+2.47 m
The 2024 storm at the Port-Aven quay, the highest of five floods cut into the granite since 1910.
Port-Aven tide gauge PA-1
Flood
4 times
The 1-in-50 flow at gauge V-07 has been reached four times since 2016 on the Lône at Vire-sur-Lône.
River gauge V-07, 1968–2026
Drought
71 days
Days below the soil moisture alert at 30 cm in Sèvre-Basse in 2025, against 34 in an average year.
Soil probes, Sèvre-Basse
( Method
Four phases,
the same on every site.
Each phase ends with a document the client keeps. Nothing moves to the next phase without a signature.
01
Hindcast
6 to 9 weeks
2 m terrain model · 120 years of storms · flood and drought maps to 2075
We replay 120 years of storms, river flows and dry spells on a 2 m terrain model of your site, then show you what the next fifty look like.
02
Design
8 to 12 weeks
Options with prices · model of each option · permit file
The defence the model asks for: a dune, a flood field, a hedge line. Never a wall by default, and every option priced.
03
Build
4 to 14 months
Local crews · weekly site report · handover file
Local crews, local stone, and our site lead on the ground every working day until handover.
04
Measure
10 years
Sensors · monthly public report · annual outside review
Sensors stay for ten years. A reading every ten minutes, checked once a year by an outside reviewer.
( Three fronts
Coast, river, farmland:
what we build on each.
01
Coast
— Living shorelines and saltmarsh
— Dune rebuilding and sand fencing
— Rock revetments where a wall is the only option
— Overflow sills and managed realignment
02
River
— Flood expansion fields
— Setback levees
— Leaky dams and wet woodland upstream
— River gauges with public readings
03
Farmland
— Winter cover crops with 41 farms
— Keyline ponds and swales
— Hedgerows and infiltration strips
— Soil cores every season, lab-verified
( Sources
Where our numbers
come from.
01
Terrain model 2 m
National LiDAR, resampled per site
Read the method →
02
Tide records from 1910
Port-Aven harbour archive
Read the method →
03
River flows 1968–2026
Gauge V-07, Lône-Vire Water Agency
Read the method →
04
Soil cores
Northfield Soil Laboratory
Read the method →
05
Annual review
Kerrow & Lisle Hydrology
Read the method →
( Team
Forty-six people,
nineteen of them on site.
Erik Halvorsen
Co-founder & Head of Field
Nantes
Ines Carvalho
Co-founder & Head of Coastal Engineering
Porto
Jonas Vermeer
Lead Hydrologist
Rotterdam
Adaeze Okafor
Soil Scientist
Nantes
Rui Matos
Field Operations Lead
Vilamar
Saskia de Groot
Director, Public Partnerships
Rotterdam
Kenji Arai
Head of Data & MRV
Nantes
