Technical solutions can be small-scale and/or big-scale.
Use of rainwater
Rainwater collection and storage solutions are still in use on islands, and it is possible to purify rainwater so that it can be used for drinking and cooking. We all have the right to drink the water we please, but we don’t have the right to sell it to others unless it is controlled and approved by the authorities. Rainwater harvesting isn’t rocket science, but it is still a technology.
Example 10: on Cape Clear Island, one of the two Irish Summer Colleges run by the co-op, collects rainwater from the roof, stores it in a harvesting tank, pumps it to a storage tank on the attic and uses the rainwater to flush the toilets in the college. If there is not enough rainwater, ball cocks in the storage tank will automatically switch to the municipal water system.
The other college does the same thing but uses water from a stream practically running through the school building.
Pretty much every house on Inis Oírr had a rainwater tank, but when the pipe system was installed in 1971, reservoirs were converted into storages etcetera. Fifty years later, the island co-operative is running courses in rainwater harvesting, water sampling, septic tank repair and maintenance, as part of their work in facilitating and encouraging good and innovative environmental practices.
Household water saving
Older water closets use larger flush volumes compared to modern ones: during the latter part of the 20th century there were toilets with about 6-10 litres flush volume, while toilets installed in the late 1990s had flushing volumes as low as four litres in many countries. During the last decade, new toilets give you a choice between two flush volumes: 2 and 4 litres.
Washing machines and dishwashers from the 21st century are more water-efficient than older machines. Water taps in kitchens and sanitary facilities (especially showers) save water due to a change of quantity and size of the outlet holes.
Sometimes, technology can be surprisingly simple.
The WiCi is an ingenious French product. The water you use to wash your hands is stored in the sink. Next time you flush the toilet, you use this water to rinse the toilet whereafter you wash your hands in clean water and fill up the sink, again. As we flush away some 10,000 litres a year per person, this recovery of water from the washbasin is smart water saving.
A simple WiCi model costs 399 euro. On Sein, where the consumer pays 6.78 euro per m3 of water, the return on investment for a couple with two children would be two years.
At the community level, an authority can promote or even distribute simple, household technology for free.
On Inis Oirr, the 25 houses that use most water had new showerheads, taps, toilets and bags in cisterns installed two years ago. The products installed were all easy to retrofit and did not require breaking into the plumbing / water supply / pipe work. The result is a reduction of 2.3 million litres in water consumption in these 25 households during two years. With 589 litres a day as the average amount of water for a typical Irish household and a typical household of 2.6 people, the people living in these 25 houses have reduced their water consumption by 38 %, from 128 litres/person/day to 79 litres/person/day.
On Sein, 300 ECO-sets have been distributed free of charge to the households by the Region of Brittany, ADEM and AIP. At the moment, there are no figures to show the saved amounts of water.
Keeping a keen eye on consumption.
A US company has developed a device called The Fluid. It measures the pressure and flow of water consumed in an apartment or a hotel room, and can monitor for what it is used: flushing the toilet, taking a shower or running the washing machine, all of which create different patterns. This can be displayed on a smartphone or monitored on a screen in the lobby of a hotel that really wants to “go green”, involving the guests in common water saving without being repressive.
The impressive information technology with which the water system of Vis can be supervised, calibrated and developed. Good, accurate, reliable data is the basis for just and efficient saving and conservation efforts.
Groundwater discharge from a borehole can be stopped when at risk of desalination, and water discharge switched to another “magazine”, letting new fresh groundwater flow into the borehole area. This might take some time but you can usually restart the borehole after the next rain period.
Favignana is an island to the west of Sicily. Its area is 20 km2 and the population is 4,300 people. The A. Rallo School is one of Italy’s small island schools, facing organisational and didactic challenges every day, ranging from the size of the structures to the multi-age classes, from the reduction of the staff allocated to frequent teachers’ turnover jeopardising teaching continuity. It is therefore especially admirable to see how the school has engaged in a water consumption assessment study.
The school was built around 1980 as a one-floor building with 96 pupils and 16 teachers. It has double piping for both tap water and well water (the latter is used for flushing water, sweeping and garden irrigation). It has been shown that male and female students have different behavioural patterns, that toilet flushing was 54 % of the total consumption, and that water leakage was 55 % of the total water consumption.
Obtained data were used to implement water saving at the school level.
“Ignorance is the root and stem of all evil”, said Plato. Yes.
A significant amount of water is lost in the water supply systems. Finding leakages is a very complex task. Over the years, different non-intrusive techniques have been used to monitor and identify the leaks, for example, visual techniques such as closed-circuit television, electromagnetic and radio frequency techniques such as magnetic flux leakage, ground penetrating radars, acoustic and vibration techniques like sonars, vibro-acoustics, and others such as infrared thermography and laser surveys.
Leakages are a major problem and can exceed 40 % of the water produced, wasting money and energy.
Let’s go back to Cape Clear Island “There is plenty of water. Why do we have to save?” as local co-op manager Máirtín O’Méalóid says, and answers himself: “Because of the leakages.”
The pipework has been leaking heavily for over twenty years, due to large trucks and other heavy machinery being transported to the island, causing damage to the system. Old tanks were also leaking heavily, meaning there was reduced storage capacity.
Wells were being over-pumped in an effort to supply water to the system, although most of it was leaking out before it reached any house or business. Sometimes the water would be switched on at storage tanks but would be gone quickly because of a pipework failure due to the sudden pressure.
The island struggled to provide sufficient water during the summer months, water supply was switched off at night during the tourist season.
An investment of approximately 4.3 million euro will finally replace and rehabilitate 11.5 km of old water mains and other infrastructure on Cape Clear Island, resulting in the saving of an estimated 11 million litres of water per year on the island. It will also result in fewer burst mains, leaks, and disruptions to drinking water supply.
View of Cape Clear Island