CAT’s water cycle

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We trace the cycle of CAT’s water: from the nearby streams that feed the reservoir, through treatment, and finally its eventual return to the river Dulas.

Water cycle1. CAT’s water comes from two sources: some is piped from a nearby stream in a boggy valley nearby, and some comes from a stream in the reservoir’s valley.















2. The reservoir, which is nestled in the hills behind CAT, holds some of the water used on-site. A recent diving expedition into  the reservoir found it to descend to 2.5 metres at its deepest point. The other sources of CAT’s water are rainfall into the lakes, ponds and rainwater butts on-site.













3. The water is ‘siphoned’ from the bottom of the reservoir. This is when the pipe is filled with water until atmospheric pressure is enough to force it from the bottom of the reservoir up and through the dam. This method doesn’t use a pump, which ensures that the system is low-energy.

4. Water is then piped down to CAT.

















5. Water to be used for drinking passes through sand filters to remove pollutants. While this process effectively removes pathogens, the water is later treated by UV to satisfy legal requirements.

6. Grey water and foul water from CAT flows into these holding tanks from site.

7. It then flows into a series of reed beds which sit below the CAT site.

8. The reed beds clean the water by a combination of the micro-organisms in the reed beds, and the physical and chemical properties of the reeds.

9. Once cleaned, the water flows back to the river which runs below CAT.