why don't canals flood?

Question

with all this bad weather, all the canals are normal, how can this be?

Answer 1

usually they have overflows near the locks where the excess water drains.

Answer 2

A couple of years ago in a drought situation, a friend of mine who owns a canal boat was saying that the canals were in danger because they were running out of water at the top of the canal.

There is a water store at the top of a canal which is topped up with rain. The locks control the flow of water as it drains to the sea. As the lock is used the water from that section is released into the lower section.

The rain will be good for storing up the water level. As the locks are used constantly then the flow of water is always controlled

Answer 3

Surprising isn't it when one reads that around 30% of the England and Wales catchment drains into canals. Usually low land areas flood and in these locations canals are elevated almost like causways and are sometimes even carried on aquaducts above valleys. Clearly where canals transverse areas of differing heights or levels locks are employed. In order for these to fuction there must be a source or supply of water to the canal at its highest point above sea level. In dry Summer conditions it is not uncommom for farmers to request that the canal water is used for irrigation. This too confirms that the water in the canal is above their adjacent land and can be gravity fed.

Answer 4

Rivers flood because they are the natural drainage route for inland water to the sea.
large amounts of rain in one area causes a pulse of water that the width of the river cannot contain and floods occur from the source and work their way downstream to the sea.

A canal is not a natural drainage channel so they do not get all the rainwater draining into them.

Answer 5

They have overflow areas for when the levels rise, which lets the excess water go into the nearest river. Otherwise some sections would flood every time a boat used the locks.

Answer 6

This is a guess.
Canals are man-made ie not natural, therefore they are in places which dont get much rain or dont naturally have water coming to them.
Rivers are in places that obviously do attract water.
Some canals are aquaducts and are high-up above ground so nothing runs into them.

I've just seen Trevor's answer - his looks clearer than mine. Well said Trev.

Answer 7

Que canal?

Answer 8

maybe because the gates keep the water at bay so the rivers don't overflow