Waterway, characteristics

Fairway

Breadth

The fairway, delimited where necessary with buoys (green on the left bank and red on the right) has the following minimal breadth:

  • On a rocky bed: 40m
  • On an alluvial bed: 60m

Depth

The fairway at present permits the following minimal depths:

  • 4.20m from the sea to Pinhão and from Pocinho to Barca d'Alva;
  • 2.50m from Pinhão to the dam at Pocinho (although there are stretches where it is more).

Gradient

The gradient of 125 m between the sea and Barca d'Alva is overcome by means of 5 locks that all have the same breadth (12.1 m) and a length of between 86 and 92 m along the longitudinal axis. A ship that is 83 m long can use all the locks along the Douro, and longer ships are able to use some of them. However, these ships require prior authorization from the IPTM (North and Douro Delegation) before seeking passage. The great advantages offered by the river may be seen if we compare the quantities of freight that may be transported 1 km using only a litre of fuel or the equivalent in electricity:

  • By boat: 100 tons;
  • By train: 67 tons;
  • By lorry: 20 tons.

The Advantages of River Transportation

A ship designed for both river and sea travel can transport the equivalent of:

  • 100 25-ton lorries;
  • 11 trains consisting of 11 20-ton wagons.

The cost of transporting freight from Sardoura to a port in the North of Europe by river and sea is around 1/5 of the price of transport by road. The waterway also contributes to the protection of nature, as there is less fuel consumption per ton transported, it is less noisy and helps to reduce the amount of traffic on the roads.


Typical volumes on the Douro
Average Maximum that may be turbined Exceeded on average 10 days/year Flood of January 1962
Pocinho 442 948 1 700 10 700
Valeira 480 1 140 2 400 12 700
Régua 549 1 000 2 800 15 700
Carrapatelo 583 950 2 900 16 000
Crestuma-Lever 714 800 3 200 17 000
Troço Fluvio-Marítimo 714 1 320 3 200 17 000

Locks
  Minimum guaranteed depth Depth of the ground sill at the upper gate Reservoir quotas Approximate filling time (min.) Maximum gradient (m)
Approach to lock lower level (m) Lock chamber (m) min. (m) max. (m) min. (m) máx. (m)
Crestuma-Lever 4,2 (a) 4,2 (a) 4,2 5,7 11,5 13,0 8,5 13,9
Carrapatelo 4,3 4,3 4,2 5,7 45,0 46,5 12,5 35,0
Régua 4,2 3,7 4,2 5,7 72,0 73,5 11,0 28,5
Valeira 4,2 3,7 4,2 5,7 103,5 105,0 11,0 33,0
Pocinho 4,2 4,2 4,2 6,2 123,5 125,5 11,0 22,0

Free Height above water level
Work Height at lower side Maximum navigable level Minimum navigable level
Period of floods Period of drought Period of floods Period of drought
Ponte de D. Luiz I 11,8 (a) (Preia mar) 2,0
(Baixa mar) 0,0		 - (Preia mar) 9,8
(Baixa mar) 11,5
Passag. S/ porta jusante eclusa Crestuma 13,0 6 2,8 (b) 7 10,2
Viaduto sobre a eclusa de Crestuma 21,5 13,0 13,0 8,5 8,5
Ponte metálica de Entre-os-Rios 31,5 15 13,0 16,5 18,5
Muro máscara da eclusa de Carrapatelo 28,9 21,65 14,5 7,4 15,4
Viaduto sobre eclusa do Carrapatelo 54 46,5 46,5 7,5 7,5
Ponte de Mosteirô 53,7 (c) 46,5 46,5 7,2 (c) 7,2 (c)
Muro máscara eclusa da Régua 59,6 52,5 49,6 7,1 10
Viaduto sobre eclusa da Régua 81,0 73,5 73,5 7,5 7,5
Ponte estrada do Pinhão 81,3 74,0 73,5 7,4 7,8
Muro máscara da eclusa da Valeira 90,5 83,4 78,2 7,1 12,3
Viaduto eclusa da Valeira 112,5 105 105 7,5 7,5
Ponte de Ferradosa 112,2 105,6 105 6,6 7,2
Muro máscara eclusa do Pocinho 116 109,0 105,9 7,0 10,1
Viaduto sobre eclusa do Pocinho 136,5 125,5 125,5 11,0 11,0
Ponte de Barca d'Alva 137,6 126,6 125,8 11,0 11,8

(a) Tidal zone. The 1962 floods reached the 8.5 m mark at its highest point, a level much higher than the maximum possible for navigation.

(b) Tidal zone - amount at high tide.

(c) Valid for a channel 30 metres wide with axis under the arch. The free height even at the arch is 7.6m.