info@eelpassages.com
Silver eel – ready for the sea.
VDV tech Eel Passages gets them there safely.
The ONLY passive, no‑electricity, HDPE gravity siphon
for downstream silver eels.
VDV tech Eel Passages is the first – and still the only one.
VDV tech Eel Passages – Silver eel passage. Finally.
Silver eels are the last hope for eel populations.
Without them reaching the ocean, there are no glass eels, no eel farming, no wild eels. Yet almost no one helps silver eels downstream.
VDV tech Eel Passages is the first passive, no‑electricity system designed
specifically for silver eels.
The silver eel bottleneck – why it matters
- Only silver eels spawn. No silver eels to sea = no next generation.
- Every dead silver eel at a dam means thousands of future glass eels lost.
- Regulators are starting to demand silver eel passage – but few solutions exist.
VDV tech Eel Passages changes that.
No holes in dikes.
No weakening. We simply
go over the top.
How our system works (gravity siphon for silver eels)
- HDPE tube placed over the dam, sealed and primed (no air inside).
- Water flows naturally from the higher upstream pool to the lower downstream side – no pump, no electricity.
- Bottom intake – eels swim near the riverbed. Our tube sits where they are.
- Gentle attraction current (optional) – a simple, passive bleed from upstream creates a local flow that eels follow. No moving parts.
- Smooth passage – eels drift through the tube, bypassing turbines and spillways.
- Safe exit – released below the dam, unharmed, on their way to sea.
Eel Passages is designed for the thousands of small and medium barriers (weirs, pumping stations, tidal sluices) that together kill far more eels than large hydro dams. For very high dams (>10 m head), trap‑and‑transport remains necessary. For the other 95% of barriers, VDV tech Eel Passages offers a cheaper, no‑handling, no‑trucking alternative.
Specifications
- 4.6 m diameter (octagon)
- 21 m² riverbed coverage
- 60 bottom‑entry holes (10 cm diameter, facing down)
- 8 radial gangway tubes leading to the centre
- Adjustable legs (5–15 cm)
- No electricity, no moving parts
- Warranty: 2 years on frame and welds
VDV tech Eel Passages – big coverage. simple design.
Why existing fish lifts fail for silver eels
Most expensive fish lifts are built for strong, upstream salmon. Silver eels are different:
- Weak swimmers – cannot fight high velocities.
- Bottom dwellers – surface intakes miss them.
- Nocturnal – visual counters don't see them.
- Sensitive to turbulence – conventional lifts injure them.
VDV tech Eel Passages is built for eels, not salmon.
What you receive – choose from TWO designs
Octagonal ring system – large coverage. ➜
4.6 m diameter. 21 m² of riverbed.
60 bottom‑entry holes (10 cm diameter, facing down).
Rectangular compact and simple, ideal for narrower waterways.
Coverage: 1.5 m².
Features: 12 bottom‑entry holes (10 cm diameter, facing down).
Why no one else has built a simple, reliable silver eel passage – until now
Most people think a tube over a dam is easy. But three real‑world problems stop almost everyone:
- Covering enough river width – a single 30 cm tube catches only a small strip. Eels swim across the whole river, not in a line.
- Debris and sand – leaves, sticks, and silt clog intakes, block tubes, and need constant cleaning.
- No clog‑free, low‑maintenance design – screens fail, moving parts break, and manual cleaning is not practical.
Eel Passages solves all three:
- Wide coverage – our 4.6 m diameter intake ring covers 21 m² of riverbed with 60 bottom‑entry holes (10 cm diameter, facing down). Eels find it from any direction – no need to aim for a small opening.
- Debris‑proof by design – all holes face downward. The ring sits on short legs above the riverbed. Leaves and sticks pass underneath – they cannot enter. No screens, no covers.
- Self‑cleaning – smooth HDPE bore and passive gravity flow mean nothing to clog, nothing to break, no daily maintenance.
That is why VDV tech Eel Passages works – and why no one else has built it.
Works in fresh, brackish
and saltwater – no rust,
no corrosion.
Proven engineering – grant‑ready partner
We are not a startup with a sketch. Our founder previously built a large‑scale tube‑based algae cultivation system that received substantial grants and was featured on CNN and the cover of Biodiesel Magazine. The same HDPE tube technology now serves silver eels.
We know how to win grants. We know how to deliver.
Who needs Eel Passages?
- Hydropower operators – comply with eel regulations without shutting down.
- Dam owners – stop killing eels, avoid fines.
- Environmental agencies – a working tool for eel recovery.
- Research institutions – test a new method on your site.
See our factory and knowhow – you are welcome
We manufacture together with a long‑term Dutch partner: a large HDPE product factory that built all Biodiesel and Algae systems with us. The same factory now produces our proprietary HDPE tubes, manifolds, water storage tanks, and connectors – everything we use in our silver eel passage systems.
Want to visit our factory, see our product lines and knowhow? Just let us know.
VDV tech Eel Passages comes with a 5‑year warranty on all HDPE and stainless steel components – no rust, no degradation, no moving parts to fail.
Ready to protect the silver eel – and your eel future?
Contact us for a free site assessment, a pilot installation quote, or a grant partnership discussion.
VDV tech Eel Passages is surprisingly affordable.
Contact us for a site‑specific quote. Rental options are also available.
VDV tech Eel Passages – the first downstream silver eel passage that actually works.