It's Saturday morning, and time for the latest episode in the occasional limited series: Dr Lee posts about water supplies

Today, Berlin

Visitors to Berlin, if not too inebriated or excited about being turned away at the door of Berghain, may have noticed these. Street water pumps especially prevalent in the West of the city.

Berlin sits on the river Spree, which in fact ran along a glacial valley between Warsaw and Berlin in the ice age. As a result the city sits on a rich bed of groundwater.

Each pump is actually a working well into that water table, acting as an emergency water source.

In the aftermath of the second world war, much of the city's water infrastructure was destroyed. These wells provided much needed clean water to those still in the city.

During the cold war, with West Berlin authorities fearing another blockade, the wells were kept well maintained.

The quality of the water from these wells are still rigourously tested, most cannot pass very strict drinking water standards, and are marked with signage as such.

Nonetheless in the event of a disaster, authorities in Berlin maintain a supply of chlorine tablets to disinfect water making it safe to drink.

There are also strict laws against washing your car for instance, to protect groundwater purity.

An inexpensive way for the Government to maintain these pumps are to encourage their use. As regular movement of the mechanism helps prevent silting. Residents are encouraged to use to pump to water neighborhood plants, to help keep them running

Incidentally, remember the groundwater I mentioned earlier? Visitors can't fail to have noticed THESE. Networks of blue and pink pipes running across the city.

Groundwater levels are rising in Berlin, and construction is constant. The pipes pump water from the construction sites into the Spree. Their colours represent the different companies that do the pumping.

*ende*