water

How Rotterdam Uses Water to Protect Itself from Flooding

- Adam Clare

As global warming melts the polar ice caps we are witnessing a human caused increase in sea level. The city of Rotterdam is on the front lines of holding back this tidal increase and they have designed some nifty ways to protect the people that live in the city from the encroaching waves. They are using a rive that flow through the city to act as a giant sponge to absorb any influx of water from storms, this will contain and slow the water from entering parts of the city with lots of people or commerce. It’s a nature-friendly way to deal with a human caused problem.

A €2.3bn “Room for the River” project – making floodplains at more than 30 locations on four rivers – is credited with saving the country from the worst flooding this year. The national delta programme is investing in action to guard until 2050, and a multi-billion euro flood protection programme (HWPB) involves 100 projects to strengthen kilometres of dykes, without which, says Rijkswaterstaat infrastructure organisation, 60% of the country would regularly be under water.

But in cities, too, water protection must meet urban design to create an attractive, adaptive city, says Arnoud Molenaar, Rotterdam’s chief resilience officer. A vast amount of work has been going on, and the city has built water squares, green and blue roofs and a 2km-long railway viaduct rooftop park. The water squares, also designed by De Urbanisten, are, very simply, built in overflow areas – when there is too much rainwater they fill up, and then slowly drain away so that the storm drains are not overwhelmed. And when the water has gone, they become public spaces again.

Read more.

Desalination on the Cheap for the Masses

- Adam Clare

ocean shore
Water water everywhere and plenty of drops to drink. Researchers from MIT have found a way to passively convert seawater into drinking water using a setup so simple it seems too good to be true. Their device basically uses heat from the sun rays and a siphon. The apparatus produces more water and rejects more salt than other passive setups, it can generate five litres of water if the device is one square meter in size. All of this with no external energy. They have even tested the device in open water – and it works! Imagine hundreds of these devices floating on the ocean bringing drinking water to cities.

The heart of the team’s new design is a single stage that resembles a thin box, topped with a dark material that efficiently absorbs the heat of the sun. Inside, the box is separated into a top and bottom section. Water can flow through the top half, where the ceiling is lined with an evaporator layer that uses the sun’s heat to warm up and evaporate any water in direct contact. The water vapor is then funneled to the bottom half of the box, where a condensing layer air-cools the vapor into salt-free, drinkable liquid. The researchers set the entire box at a tilt within a larger, empty vessel, then attached a tube from the top half of the box down through the bottom of the vessel, and floated the vessel in saltwater.

In this configuration, water can naturally push up through the tube and into the box, where the tilt of the box, combined with the thermal energy from the sun, induces the water to swirl as it flows through. The small eddies help to bring water in contact with the upper evaporating layer while keeping salt circulating, rather than settling and clogging.

Read more.

Existing Water Filters Can Catch Microplastics

- Adam Clare
wc sink

Plastic waste is everywhere and the tinier the plastic is the harder it is to deal with. These microplastics are proving to be very difficult to address which has sent researchers looking into all sort of solutions. One solution is already up and running in some places: sand filters in water systems. It turns out that some existing sand filtration systems can capture plastic nano particles.

The results are now in, and they include some reassuring findings. In a report published today in the Journal of Hazardous Materials, the researchers show that even if untreated water contained considerable quantities of nanoplastics, these particles were retained in sand filters very efficiently during water treatment. Both in laboratory tests and in a larger test facility located directly on the premises of the Zurich Water Works, the biologically active slow sand filter was the most effective at retaining nanoparticles – achieving an efficacy level in the region of 99.9%.

Read more.

This City Captures Drinkable Water from the Air

- Adam Clare

fog

Aquifers feel there pressure of increasing populations and farms; as a result, cities around the world get drastically close to running out of water. The solution in some places may have been under our noses the entire time: fog. In Lima they already have a system in place to capture water from fog to supplement existing sources, and other coastal cities are paying attention. The coolest part of the fog catching technology is that it comes from ancient techniques using tees!

In 2009, German conservationists Kai Tiedemann and Anne Lummerich planted 800 she-oak trees in Peru to create a natural fog-catching system that aimed to replicate this ancient technique. During their research they found that trees with vertical, needle-like leaves work as an organic net to which drops of water adhere. They later went on to develop artificial nets that could also capture water.

Marzol has been studying “the hidden precipitation” in fog for nearly 25 years now, partly because modern meteorological instruments struggle to measure its relationship with precipitation. During the course of her research she has witnessed the social transformation that can occur in communities that collect fog water.

Read more.

Cities of the Future Act as Sponges

- Adam Clare

When it rains cities should hold all the water. In the 20th century that idea would have been laughed out of the room; today, we know better. Urban water management is vital to a healthy city, ecosystem, and flood mediation. The old idea of building giant channels of concrete to force water out of their natural areas (the best example of this is in L.A.) is thankfully being replaced with better ideas.

One of those better water management ideas is to just soak it all up. Make the city a sponge.

It tries to do it in three areas. The first is at the source, where just like a sponge with many holes, a city tries to contain water with many ponds.

The second is through the flow, where instead of trying to channel water away quickly in straight lines, meandering rivers with vegetation or wetlands slow water down – just like in the creek that saved his life.

This has the added benefit of creating green spaces, parks and animal habitats, and purifying the surface run-off with plants removing polluting toxins and nutrients.

The third is the sink, where the water empties out to a river, lake or sea. Prof Yu advocates relinquishing this land and avoiding construction in low-lying areas. “You cannot fight the water, you have to let it go,” he says.

Read more.

Scroll To Top