A Dutch property company, Beladon, has designed and constructed a floating dairy farm, currently anchored to the sea bed in Rotterdam’s Merwehaven harbour, writes Venetia Taylor
The structure houses 32 cows (milked and mucked-out by robots powered by solar panels) and a vertical farm.
It can tolerate tidal swings of up to around 5 feet and is designed not to tip; even if all the cows congregate on one side.
It is made of concrete, with a galvanised steel frame and a soft membrane floor designed to let rainwater and urine soak through to be collected and purified.
The cows inhabit the top two floors and the bottom level is used for growing duckweed, red clover, alfalfa and grass to feed to the cows (grown under LED lights and watered with the purified urine).
The farm achieves various environmental aims.
It brings farming close to the city centre, reducing the carbon footprint of its produce.
The cows are fed with waste food products from the city and hay from local playing fields; manure is sent to a nearby farm.
Its inventors hope that, if sea levels rise permanently, floating farms could be used to help mitigate loss of arable and pasture land.
Would a similar scheme make sense in the UK? In purely commercial terms it is unlikely that the Rotterdam project makes sense.
The cost of setting up the floating farm was in the region of €2.6m.
Although Holland has the most expensive farmland in the EU, pasture to graze 32 cows might cost around €1m (roughly 25 hectares).
In the UK we do not face the same practical constraints; we have more land and less flooding.
In England the approximate cost of 25 hectares of pasture land is more like £250,000. This model will not make financial sense for many UK farmers.
Part of the rationale for the project is similar to that for floating solar; it is an attempt to make efficient use of otherwise wasted space.
The difference is that water-mounted solar farms are relatively cheap to set up, simple to run and eventually pay for themselves.
Add to this the complexity of English land law and planning systems.
Floating structures such as these need to be fixed to the sea or river bed. The presumption in English law is that a riparian owner owns the bed of the river up to the centre line and could therefore legally affix a floating farm to his part of the bed [of a non-tidal river].
The farm could not obstruct the watercourse or interfere with any public rights of navigation and, if it strayed over a part of the bed owned by someone else, this would constitute a trespass.
UK tidal and coastal beds are almost all owed by the Crown.
Permission could theoretically be granted for projects such as these off coastal towns and in harbours if there were the political goodwill to do so.
These are all obstacles that could be overcome by determined private investors.
Given that no real and present problem is solved for UK farmers by floating cows on water, it would seem to be a project for a private investor keen to display eco-credentials.
Venetia Taylor is a solicitor at Payne Hicks Beach