Through a series of pumps and electricity, from the USGS Water Science School:
Let’s assume that you get your water from the local water department through pipes buried below the streets. In other words, you don’t have your own well in your back yard. Chances are that you get your water through gravity and pumps. Cities and towns build those big water towers on top of the highest hills and then fill them with water. So even if you live on a hill, there’s a good chance the water tower is higher than your house. Water moves from the tower, due to gravity, and goes down a large pipe from the tower to eventually reach your house.
Although gravity supplies the power to move water from the tower to homes, electricity is needed to run a pump to push water from the source.
In my city, those water pumps use a lot of electricity. It is the second largest city expense, using 5.4 million kWh and costing more than $500K a year. (Energy Action Plan, page 21)
I’ve got two maps for you. The first is the slippy map above from London Town:
I like the…hand-drawn feel of the map. Venues are shown in indicative locations rather than being geographically correct, as the details of London between the venues are missed out. This makes it a very poor map for navigating around London between the venues, but a good graphic illustrating just how many venues in London there are, and how they relate geographically to the major London landmarks. – Mapping London
Second, is the one you would pick up in the London Tube if you were going to the games. Created for the Olympics, the “London Summer 2012″ map looks like a pretty cool brochure/souvenir for the games:
The maps feature key landmarks, the locations of Olympics related events (such as London Live) and shops, a selection of interesting museums and also more practical information such as public amenities, police stations and NHS walk in centres. The maps also include 6 discovery trails (round trips) to help explore different areas (such as the City; Spitalfields and Brick Lane; Regent’s Park; and the West End).
Two screenshots of it below – more at – Mapping London