In order to guarantee the supply of water to the always growing urban agglomerations, infrastructures must be built to convey this liquid resource, bridging valleys and crossing ranges of mountains.
Every time a topographic accident is found, a tunnel is the only solution to provide a smooth free way to water.
On some other occasions, big engineering schemes are drawn in countries where severe differences in the hydrological balance occur all over their surface, and water is unevenly distributed.
This situation tends to grow as climate change is making weather patterns less predictable. Seasonal flooding appears to be getting more extreme, and droughts more frequent and severe.
One solution to regulate this uneven situation is the transportation of water from more humid places to regions that suffer from drought and lack of rain. A solution that normally leads to major engineering projects where tunnels play a very important role.
An example is the vast water channel under construction in China to transport water from the south to the north, where a vast number of tunnels are being built to cross the main mountain ranges intercepted by the channel.
Related case
- Lesotho Highlands