How are reservoirs made?
Reservoirs are either man-made or natural. Natural ones are
part of the land and are not made by people. Lakes and ponds
are natural reservoirs. We visited a natural one that was
donated by a family so that the town would have another water
Building a man-made
reservoir is a big job. It takes from 5-8 years to plan, three
years to build, and costs lots of money, too. We visited the
New Jersey Water Authority and talked to them about
reservoirs. This water facility manages 25% of New Jersey
water. We learned a lot about the building of two very large
In the 1950s, New Jersey had a drought.
Water companies were asking questions like:
||How do we get
water to meet the needs of the people?
||How are we going
to meet these needs in the future as more and more
development takes place?
The state estimated how much water
was needed for the next 80 years and then built two large
reservoirs. Unhappily, the estimates were wrong because no one
guessed how many people would move here and how much development
would happen. The state needed to plan for the future earlier
than they thought they would. We were told that the goal is to
make sure that when people turn on water it is always there.
This is known as a 'never-ending' supply.
Planning is important in making a
reservoir. Once the engineers find a good water source, they
decide how large the reservoir needs to be. They begin
to buy any property that will be under water when the reservoir is
A large structure [on the left] is built to send the water out of
the reservoirs. It goes to the towns and water companies that
buy it. The amount of water going out of the reservoir is
controlled here. Inside this building is a crane-like machine
that lifts panels and drops them into a slot to cover the
openings. This lets less water out of the reservoir.
When there is a whole lot of rain or melting
snow, a reservoir can get too high. Spillways are made so that
water can overflow into nearby rivers and streams to keep the
reservoir at the level they want it.
On the left is a spillway. We were surprised to see
these spillways have so much animal life in them. It was easy
to see that wetlands and watersheds are important to our water
supply AND our environment.
The picture on the right is where water is being
taken from the reservoir and being sent into a stream that will flow
into a river.
The Water Authority also has a old canal system
that they use for water distribution.
In the past, it was used to move goods from place to place.
This facility rebuilt it and they use it like it is a
reservoir. There are locks that
raise and lower water levels and aqueducts
that move it from place to place. Towns along the canal can tap
into it to get water when they need it.