Gatunsee

Gatunsee
	Gatunsee with the Panama Canal
Location:	Panama
Tributaries:	Río Chagres
Drain:	Río Chagres
Larger places nearby:	Colón
	Panama
Coordinates	9 ° 11 '23 " N , 79 ° 53' 15" W Coordinates: 9 ° 11 '23 " N , 79 ° 53' 15" W.
	Data on the structure
Construction time:	1907-1913
Height of the barrier structure :	32 m
Height above foundation level :	35 m
Height of the structure crown:	35 m
Building volume:	17 million m³
Crown length:	2300 m
Crown width:	30 m
Power plant output:	6 MW
	Data on the reservoir
Altitude (at congestion destination )	26.5 m
Water surface	425 km²
Storage space	5200 million m³
Design flood :	4100 m³ / s
	This map from the construction period shows the area around the dam and the locks, drawn over the excavations by the French

The Gatúnsee ( Spanish : Lago Gatún ) is an artificial lake in Panamá , which was created for the construction of the Panama Canal by the damming of the Río Chagres . The Gatunsee, including the Gatun dam and the hydroelectric power station, as well as the entire catchment area of the Río Chagres, are under the administration of the Panama Canal Authority (Autoridad del Canal de Panamá [ACP]).

Reservoir

The lake is located on the territory of the two Panamanian provinces of Colón and Panamá . The lake was created between 1907 and 1913 through the construction of the Gatún dam and the associated damming of the Río Chagres , making it the world's largest artificial lake of that time. A 29 km long section of the Panama Canal leads through the Gatunsee, in which only the fairways had to be dredged. In addition, due to the damming of the Gatúnsee at 26 m above sea level, the passage of the canal through the mountains did not have to be excavated below sea level. The ships traveling through the Panama Canal reach it through locks .

The reservoir has a water surface of 425 km² (in another spring 423 km²) and a storage capacity of 5.2 km³, from which an average depth of 12.2 m is calculated. The reservoir volume corresponds roughly to the total amount of water that flows into the Río Chagres in an average year. The locks are operated with the water from the reservoir; Therefore no water needs to be pumped up at the locks. The lake is around 26 meters above sea level and is very rich in fish today. The species introduced include fish from all over the world.

The reservoir not only flooded the city of Venta de Cruces, from which the goods transported overland from old Panama were transported by ship on the Río Chagres to the Caribbean Sea , but also a large part of the old railroad from Panama to Colón . However, the railroad was absolutely necessary for the construction of the Panama Canal and therefore had to be rebuilt over long distances. The artificial lake also flooded an originally densely wooded depression with tropical rainforest ; apart from the marked canal route, parts of the flooded vegetation can still be seen today. Only the trees in the direct channel of the canal were felled at that time. Many former hills in the valley have now become islands. The largest and most famous is the island of Barro Colorado , which houses a large research station and has become a destination for excursions.

Gatun Dam

Earth dam

The Gatún Dam was built between 1907 and 1913 a few kilometers from the mouth of the Río Chagres into the Caribbean Sea as part of the canal project. It is located immediately southwest of the Gatun locks at a point where the mountains left a gap of only 2 km in the valley of the Chagres, in the middle of which there was a natural rock. The dam on both sides of this rock is a total of 2300 m long and 32 m high. At its base it is 640 m wide, at the height of the water level 121 m and at its crown, which is 9 m above the water surface, it is still 30 m wide. It contains 17 million cubic meters of bulk material. The dam consists of two stone walls with a sealing core in between. This impermeable core consists of washed-in soft clay that was present nearby. Finally, the water side of the dam was secured with large boulders to break the force of the waves.

At the time of its completion, it was the largest dam in the world.

Concrete dam

On the natural rock in the middle of the two earth dams, a concrete dam with attached steel gates was built to regulate the outflow from the lake and as a flood relief . It consists of a semicircular concrete dam with a length of 225 m at the upper edge, on which 14 mostly closed steel gates stand between mighty pillars. The air side of the concrete dam is designed as a series of overflow channels, so that the water gushing down meets in the center of the semicircle from different directions, while its energy in the stilling basin is largely neutralized and flows off at normal speed through a concrete channel.

Over the upper edge of the concrete dam, which is just under 5 m below the normal water level, there are 14 gates, which are supported on concrete pillars and are each 14 m × 6 m in size. The gates can be raised and lowered electrically to control the water level. At the water level of 26.5 m above sea level, the planned maximum water level, the flood discharge can discharge 4100 m³ / s, which is more than the largest discharge in the Chagres. In addition, 1400 m³ / s can drain through the underground water pipes at the locks. Despite this, the Río Chagres carries so much water at long intervals that both Lake Alajuela and Lake Gatun reach their maximum level. Shipping traffic on the Panama Canal had to be interrupted for 17 hours from December 8th to 9th, 2010 - for the third time in the 96-year history of the canal.

Hydroelectric power plant

At the foot of the dam, on the east side of the drainage canal , there is a hydropower plant that uses three generators with a total of 6 MW to generate enough electricity to supply the locks, the flood relief gates, the lighting and other facilities on the canal.