Image: Marktplaats.

The lavet is a typically Dutch invention that was mainly used in social housing in the 1950s and 1960s. It was produced up to 1975, with a total production of about 1 million. The lavet is somewhere between a sink and a bathtub. It consists of a plateau with a raised edge, in which on one side is a 40 cm deep tub with a diameter of almost 60 cm. Unique to the design is the multi-functionality. The lavet fulfilled the functions of a bathroom and laundry room but required ​​only one square meter of space.

The tub was very suitable for washing (several) children, but adults could also take a hip bath with some dexterity. There was even the possibility to take a shower standing in the tub. The lavet was also great for hand washing clothes. The manufacturer of the washbasin marketed a washing machine and accompanying centrifuge that fit in the washbasin. The tub was also practical for gardeners: they could rinse large quantities of vegetables in it before preserving them.

Image: Marktplaats.

Image: Ralph van der Kamp. Source: Joostdevree.nl.

Image: Rijksdienst voor het Cultureel Erfgoed.

Thanks to Melle Smets.

Sources: 

• Het lavet, Joostdevree.nl
• Het Lavet, Wikipedia NL

Update:

Reader Ramino sends us some information about a similar artifact in Argentina. “The MASI (Mueble Artefacto Sanitario Integral) was developed by the Argentinian research institute CEVE (Centro Experimental de la Vivienda Económica, a joint between an NGO and the  national research council). It is (was?) made of plastic, to make both production and installation simpler and cheaper, as it is designed for cheap social housing. It seems there are two versions (one wider, and  one more compact), which integrate sink, toilet and shower, and the main idea is to reuse the sink’s greywater to fill the toilet’s deposit. Unfortunately, I don’t think it has had a very big adoption.” See:

• http://www.ceve.org.ar/componentes-1.php
• https://www.youtube.com/watch?v=Q6CH7rDBjcY

• No electricity or running parts to operate the filter
• Made with 100% locally available materials (unlike larger community based systems where foreign parts typically need to be imported)
• Labor intensive NOT capital intensive
• Very durable, can last more than 25 years if maintained properly
• Little maintenance required
• Very effective for removing bacteria, protozoa, helminths from water and reducing turbidity

The main problem with concrete biosand filters is they require a heavy, expensive steel mold to make. Concrete must be poured into the mold and allowed to cure overnight before the filter body is removed. These steel molds are very expensive and require an experienced welder to make, meaning that many communities or local NGOs do not have the technical capacity or financial resources to start a biosand filter project.

The NYC based non-profit OHorizons saw an opportunity for innovation in the concrete BioSand Filter manufacturing process. By engineering an alternative wood mold, they’ve greatly sped up the biosand filter production process. The wood mold allows on-the-ground organizations to manufacture and install biosand filters for a fraction of the upfront cost as traditional methods. The advantages of the wood mold are the following:

• Durable (~50 filters/mold)
• Cheap (~$50-80/mold)
• Lightweight (~ 60 lbs)
• Locally-Sourced Materials (all materials purchased in-country and easily replaced)
• Easy to use (no special skills or previous construction experience required)
• Can be made off-grid

OHorizons’ Resources Page contains an 81-page how-to guide for the construction of the wood mold, open source and free to download, as well as backgound information about biosand filters. The non-profit has run succesful projects in Mali, Ecuador and Bangladesh.

“Simply put, swales are water-harvesting ditches, built on the contour of a landscape. Most ditches are designed to move water away from an area, so the bottom of the ditch is built on a modest slope, usually between 200:1 to 400:1. Swales, however, are flat on the bottom because they’re designed to do the opposite; they slow water down to a standstill, eliminate erosion, infiltrate the surrounding area with water, and recharge the groundwater table. When water moves along the flat bottom of a swale, it fills it up like a bathtub — that is, all parts of the bath tub fill at the same rate. The water in a swale is therefore passive; it doesn’t flow the way it would on a slope.”

“The swale system is self-regulating. Once the available water has reached an equilibrium, meaning it has filled the lowest point and has no where else to go, it just sits there, unmoving. And as it sits, it slowly seeps into the surrounding landscape, hydrating the soil and recharging the water table below. In this way, the swale fulfills three important functions: it carries water from the ditch to fill the dam, it rehydrates the landscape, and it prevents the dam from overflowing by acting as a channel back to the ditch. Swales are great for filling dams anywhere except for arid or hyper-arid environments, where they would dry up too quickly.”

“The mounds along the swale can provide enough water to establish a tree system with little to no additional irrigation. Conventional wisdom says that you need more than 15” or 381 mm of annual rainfall to establish trees. This is not necessary when you design a swale system to aid with water catchment, because it effectively concentrates and holds the available water in that area.”

Read more: Swales: The Permaculture Element That Really “Holds Water”. Picture: SUDSnet.

Previously:

• Water Johads: A Low-Tech Alternative to Mega-Dams in India.
• Precolombian Causeways and Canals.
• Water Batteries for Trees.
• DIY Glaciers: a Low-Cost Alternative to Dams.

When the British colonized India, they imposed their own system of water management, which included the building of large-scale dams, sewers, and irrigation channels. This high-tech approach continues today, as the World Bank is urging India to build enormous dam projects to fight drought and depleted aquifers. The Indian government has followed its advice. Its first Prime Minister, Jawaharlal Nehru, called dams the “Temples of modern India”. Since then, India has built over 5,000 dams and large reservoirs. [1]

However, before the British arrived, people on the subcontinent used traditional low-cost, low-tech engineering to collect rainwater for thousands of years. This involved the placement of thousands of small structures throughout rural areas which, in one way or another, catch excess rainwater from the monsoon months and allow it to slowly percolate into the groundwater during the dry season. To maintain and manage these structures, community-based management schemes were necessary. However, these were actively discouraged during British rule and following independence. As a result, in the 20th century many of these small reservoirs fell into disrepair.

In the 1980s, the Alwar district in the North-Western state of Rajasthan was one of the driest in all of India, even though older villagers remembered that its rivers used to flow in the past. Many farmers were migrating to the cities, as there was no longer any means of subsistence from the land. In 1985, Rajendra Singh—now known as the ‘Water Man of Rajasthan’—arrived in the area and started encouraging villagers to rebuild their old water reservoirs, or water johads. When the villagers had constructed 375 johads, the river began to flow after having been dry for several decades. [2]

By 2003, Singh, through the NGO Tarun Bharat Sangh, had helped with the construction of over 5,000 johads and the rejuvenation of 2,500 old reservoirs, providing irrigation water to 140,000 ha. and 700,000 people. [3, 5] In 2015, 8,600 johads had been built, bringing water back to 1,000 villages. [4] The johads are incredibly cheap and productive—at 100 rupees per capita, they can raise economic production by as much as 400 rupees per year. Compare this to nearby Sardar Sarovar Dam project, which cost 300 billion rupees, and cost 100 times more per person supplied with water, and 340 times more per hectare irrigated. [3]

The design of water johads. Source: Anupma Sharma, National Institute of Hydrology

And yet water johads are extremely simple and low-cost structures that require no large equipment or expensive materials to build—simply a village of able hands and local elements. After digging a pit, the villagers shape the excavated earth into a semicircular mud barrier. A stone drain is sometimes set up, allowing excess water to seep into the ground, or connecting it with johads nearby. Essentially the johad will capture runoff from monsoon floods and allow it to slowly percolate into the water table during the dry months. When many johads are built in one area, they have a cumulative effect, resulting in the replenishment of whole aquifers. [5] In addition, it has been shown that the water stored in the aquifers does not draw away water from communities downstream. [6]

It’s important to note that water johads are place-specific technologies and cannot necessarily be replicated to other geographical locations or climates. They require steady sloping land—where each johad can feed water into another downstream—and a rainy season, where floods can fill up the reservoirs during the dry months.

In addition, constructing and maintaining thousands of water reservoirs also required new forms of resource management. Since the government refused to participate with the johad construction efforts, or recognize that they were effective—its policies remain tied to the development narrative. Villagers decided to take matters in their own hands and organize their own water management councils, which have now expanded to managing forests and parks through participatory and democratic methods. The result is what some have claimed a miracle: bringing water back to a water-scarce and impoverished area.

Building Community

An engineer might look at a johad and claim that it is far too simple a technology—there is no innovation here, let alone a miracle. This is true: similar technologies exist all over the world. In Mediterranean countries, for example, rain water catchments were built over a thousand years ago and continue to provide water to farmers during dry seasons.

Rajendra Singh attributes the success of the johads to the fact that the technology encourages people to work together, building community while addressing essential needs. This is in strong opposition to the large government-built dams, which have displaced millions of people in India and, on average, have increased poverty. [5]

So, perhaps the key innovation with the johads is that rather than relying on engineering expertise or governmental action, villagers have constructed the johads themselves through traditional methods and community participation. The result is the revival of a low-tech tradition that is far more cost-effective than high-tech dams could ever be.

Aaron Vansintjan

Sources:

[1] International Commission on Large Dams (ICOLD). http://icold-cigb.net/GB/World_register/general_synthesis.asp?IDA=206

[2] The Water Man of Rajasthan. Frontline. Sebastian, Sunny, 2001.

[3] Water-harvesting in India transforms lives. Alternet. McCully, Patrick. 2003

[4] An ancient technology is helping India’s “water man” save thousands of parched villages. Ghoshal, Devjyot. 2015.

[5]. Water Harvesting: Alwar, Rajasthran. National Institute of Hydrology (Roorkee, India). Sharma, Anupma.

[6]. Traditional Water Harvesting Structure: Community behind ‘Community’. Economic and Political Weekly. Vol. 41, No. 7, pp. 596-598. Kashwan, Prakash, 2006.

[7]. “Dams,” The Quarterly Journal of Economics, MIT Press, MIT Press, vol. 122(2), pages 601-646, 05. Esther Duflo & Rohini Pande, 2007.

Related: Madakas.

GIWHs are currently the least expensive form of energy storage available. Utilities can use fleets of grid-enabled water heaters for load shifting, demand response, arbitrage, ancillary services, or to respond to unexpected grid-stabilization events. Traditional dissemination of new water heater technology has been a painstakingly slow process, but water heater rental programs may greatly accelerate this process.

Read more: Battery Killers: How Water Heaters Have Evolved into Grid-Scale Energy-Storage Devices, David Podorson.

Related: How sustainable is stored sunlight?

“One winter in the late 1980s, an engineer from Skara named Chewang Norphel came up with a possible solution to his village’s problem while strolling around his backyard. Norphel noticed that a small stream had frozen solid under the shade of a poplar grove, though it flowed freely elsewhere in his sunny yard. The reason for this, he realized, was that the flowing water was moving too quickly to freeze, while the sluggish trickle of water beneath the grove was not. Over the next several years, Norphel worked to create an irrigation system that functioned using the same simple natural principle. The result has been Ladakh’s artificial glaciers. Ten
have been built to date.”

Read more: Artificial Glaciers Water Crops in Indian Highlands.

However, people obtained the same result much more sustainably before the advent of the Industrial Revolution. In hot, dry climates, we used porous earthenware jugs that were not only re-usable, but also kept water cool by taking advantage of natural energy sources.

The best known example is the Spanish ‘botijo’, an unglazed ceramic container that cools beverages by evaporation. Similar drinking containers can be found in other Mediterranean countries, as well as in Mexico (where it is known as a ‘búcaro’) and on the Indian subcontinent (where it is called a ‘ghara’, ‘matka’ or ‘suhari’).

The ceramic water cooler probably originated in the Indus Valley Civilization, which would make it 5000 years old.

Illustration: a Spanish botijo.

The botijo generally has a wide, spherical belly with two openings on top — a wide opening to pour water in the jug and a smaller drinking spout — as well as one or two handles to carry it. Traditionally, people drink the water directly from the botijo by holding it up and tilting it so that the water pours from the drinking spout.

Botijo-etiquette demands that the lips do not touch the drinking spout, as the water container is usually shared among several people, and of course the content can also be poured into a glass. The large opening is covered with a cork or a cloth after filling the jug, in order to keep insects out.

Botijos come in different sizes, but on average it contains about 3 litres of water, with larger ones holding up to 7 litres – enough to supply a small group of people with drinking water for a full day.

How does it work?

After the botijo is filled with water, it is preferably placed outside in the shade, although it also works when placed in the sun or indoors. The technology is based on evaporative cooling — the same process that keeps the human body cool by sweating. Because the ceramic jug is not completely water-tight, a small amount of the stored water filters through the pores of the clay and evaporates once it comes in contact with the outside, dry environment. Evaporation (the transition from liquid to gas) requires thermal energy, which is partly extracted from the water inside the jug, cooling it down.

The cooling potential of the botijo

The cooling potential of the botijo depends on — among other things — the shape, dimensions and material of the jug, the quantity of water that it holds, and the humidity and temperature of the outside air. It can be calculated precisely according to a complex mathematical model that was developed during a 1995 scientific experiment (PDF), which showed that under optimal conditions a cooling of up to 15 degrees Celsius can be obtained.

A botijo holding 3.2 litres of water was placed in an oven with a temperature of 39 degrees and a relative humidity of 42 percent, mimicking a hot Mediterranean summer day. It was observed that the temperature dropped by 2 degrees after 15 minutes, by 8 degrees after one hour, and by 13 degrees after three hours. In about 7 hours time, the temperature had fallen to 24 degrees, with a water loss of about 0,4 litres (eight percent of the water content). After that, the temperature slowly started to rise again. At lower outside temperatures (around 30 degrees Celsius), the cooling effect is limited to about 10 degrees Celsius. The cooling effect thus adapts to climate conditions.

Beware of tourist souvenirs

Importantly, a botijo should be unglazed in order to function properly. Glazed botijos – now often sold as tourist souvernirs – do not cool water. Glazed water containers were used to store water in cooler and more humid climates, where a porous container would be of no use.

Similar technologies

A somewhat similar cooling effect can be achieved using a canteen with a lined cover. If the canteen is submerged in water so that the cover absorbs liquid, and is then left outdoors until the cover dries up, the water inside it will have cooled. One can also observe the effect by placing a water bottle inside a thick, wet sock. Evaporative cooling is also the process behind the Zeer Pots – refrigerators that work without electricity – and it can be applied to the cooling of buildings and industrial processes. In fact, the botijo also helps to cool the environment in which it is located, because evaporation takes only part of the required energy from water — the rest is taken from the environment.

Mobile refrigeration device

Apart from the fact that the botijo does not use electricity, it offers a couple of further advantages. Firstly, it produces water that is cool but not nearly as cold as refrigerated water. Ironically, water that is cooled in a refrigerator is too cold for human consumption and can cause health problems.

Secondly, the botijo is a mobile refrigeration device — for which there exists no modern counterpart. Plastic, glass or metal bottles, which have no pores and are thus unable to ‘sweat’, start warming up once they are taken out of the refrigerator.

In contrast, the water in a botijo remains cool regarding of where it is taken, which explains why the device was traditionally used in Mediterranean countries both domestically and by farmers. Travellers often made use of the containers as smaller, cylinder-shaped botijos could be tied to horses. Even a modern, metal canteen with a lined cover does not offer the same benefits as a mobile refrigeration device, because it is not the water inside that cools the bottle. The canteen has to be soaked in water regularly in order to maintain the cooling effect, which is not always an option in a dry climate.

The importance of climate

With the advent of cheap fossil fuels, we have become accustomed to the idea that any technology works anywhere. This is seldom the case with pre-industrial technologies, which are most often local solutions. The botijo is no exception to this rule. It is especially suited for climates with hot, dry summers (type Cs of the Köppen climate classification). This climate prevails around the Mediterranean, and can also be found on the West coast in the United States (in California and Oregon), in South Australia, and in small regions of South-America (in Chile) and Africa (in South-Africa). The botijo also performs excellently in desert climates (type BW, which is much more widespread than the Mediterranean climate).

    With the advent of cheap fossil fuels, we have become accustomed to the idea that any technology works anywhere. This is seldom the case with pre-industrial technologies, which are most often local solutions.

However, the cooling function of the ceramic water cooler deteriorates as summers become more humid, as is the case in most tropical climates. Similarly, the human body is more sweaty in a hot and humid environment, because transpiration cannot evaporate.

Climates with cool and wet summers have less need for water cooling methods in the first place. This explains why some parts of Spain (notably in the north-western region) do not have a tradition of evaporative water coolers, but use glazed containers instead. This is also true for the areas near the coast of the Mediterranean, where the proximity of the sea raises air humidity.

Lifting the botijo

One of the disadvantages of a botijo is that it can be rather heavy for people who lack muscular strength. An average botijo filled with water can easily weigh 4.5 kg. However, there are some solutions to this problem.

Fundación Terra, a Spanish environmental organisation, launched a campaign a few years ago to promote the use of the botijo in homes and offices, and developed a system to suspend the bojito from the ceiling for easy drinking. In addition, they advise people to hang it above a plant so that spilled water does not get lost. In India, the drinking spout was replaced by a low-placed tap.

Kris De Decker (edited by Deva Lee). Sources: 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10.

PS: If you are looking for a smaller container, check out these unglazed clay water bottles, presented at the Green Living Show in Toronto two week ago.

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Related articles:

• Storing food outside the refrigerator: Jihyun Ryou’s anti-fridge design
• Bog butter: storing food in soil
• Pottery refrigerators
• California Coolers
• India’s ancient stepwell architecture cools modern building
• Home made air conditioner
• Insulation: first the body, then the home

Read more: Ancient ‘air-conditioning’ cools building sustainably.

“A spiral pump, first invented in 1746, has been recreated and tested at Windfarm Museum using lightweight and inexpensive modern materials. A 6 foot diameter wheel with 160 feet of 1-1/4 inch inside diameter flexible polyethylene pipe is able to pump 3,900 gallons of water per day to a 40 foot head with a peripheral speed of 3 feet per second.

With its low torque requirements, the pump is particularly suited to be mounted on and driven by a paddle wheel in a current of two feet per second or greater. This easily built, low maintenance spiral pump can be used to provide water without the need for fuel wherever there is a flowing stream or river. It can also be hand turned or otherwise driven to provide a low cost, efficient pump.”

Read more: 1 / 2 / 3 / 4. Thanks to Paul Nash.

See also:

• Power from the tap: water motors
• Back to Basics: Direct Hydropower

“Using groundwater to grow crops and trees doesn’t make sense to Pieter Hoff, a Dutch inventor. Not only are traditional irrigation techniques inefficient because most of the water is lost to evaporation, Mr. Hoff says, but water can be easily captured from the atmosphere to grow just about anything.

To prove his point, Mr. Hoff retired from the lily and tulip export business in 2003, established his company, AquaPro, and devoted himself to the development of the Groasis Waterboxx (manuals), which he says will grow food crops and trees even in the driest places on earth.” Read more.