The Alb (also: ''Hauensteiner Alb'') is a river in the southern

Black Forest The Black Forest ( ) is a large forested mountain range in the States of Germany, state of Baden-Württemberg in southwest Germany, bounded by the Rhine Valley to the west and south and close to the borders with France and Switzerland. It is th ...

. It arises from two

headwaters The headwater of a river or stream is the geographical point of its beginning, specifically where surface runoff water begins to accumulate into a flowing channel of water. A river or stream into which one or many tributary rivers or streams flo ...

, the Menzenschwander Alb and Bernauer Alb, and flows in a southerly direction. It ends after (including ''Menzenschwander Alb'') at a confluence with the

High Rhine High Rhine (, ; kilometres 0 to 167 of the Rhine) is the section of the Rhine between Lake Constance () and the city of Basel, flowing in a general east-to-west direction and forming mostly the Germany–Switzerland border. It is the first of fo ...

at Albbruck.

Etymology

The name ''Alb'' is possibly derived from a

Proto-Indo-European Proto-Indo-European (PIE) is the reconstructed common ancestor of the Indo-European language family. No direct record of Proto-Indo-European exists; its proposed features have been derived by linguistic reconstruction from documented Indo-Euro ...

word ''*albhos'' meaning "white" or perhaps "river".

Headwaters

The headwaters of the Menzenschwander Alb lie on the southern slope of the Feldberg mountain range in the

Landkreis In 13 German states, the primary administrative subdivision higher than a '' Gemeinde'' (municipality) is the () or (). Most major cities in Germany are not part of any ''Kreis'', but instead combine the functions of a municipality and a ''K ...

Breisgau-Hochschwarzwald Breisgau-Hochschwarzwald () is a (district) in the southwest of Baden-Württemberg, Germany. Fifty towns and municipalities with 133 settlements lie within the district. The district itself belongs to the region of Freiburg with the region of Sou ...

. The Bernauer Alb rises on the southern slope of the Herzogenhorn. The Menzenschwander Alb is about long and flows south-east past Menzenschwand. The Bernauer Alb is about long; it also flows south-east, past Bernau. The confluence of the two headwaters is at ''Glashofsäge'', about from

Sankt Blasien St. Blasien (; sometimes spelled in full as Sankt Blasien) is a small town located in the Waldshut (district), Waldshut district in Baden-Württemberg, Germany. It is situated in the Southern Black Forest, 17 km northeast of Waldshut-Tieng ...

. The valleys of both headwaters were widened by

glaciers A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

during the

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages, and g ...

. Both are about high and dominated by grassland. The Bernau valley is a broad basin, characterized by moraines, marshy valleys, ravines, and

Roche moutonnée In glaciology, a roche moutonnée (or sheepback) is a rock formation created by the passing of a glacier. The passage of glacial ice over underlying bedrock often results in asymmetric erosional forms as a result of abrasion on the "stoss" (upstr ...

s. The

hamlets A hamlet is a human settlement that is smaller than a town or village. This is often simply an informal description of a smaller settlement or possibly a subdivision or satellite entity to a larger settlement. Sometimes a hamlet is defined f ...

and isolated farms that make up the valley lie some distance above the frost-prone valley floor. The

glacial A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

features in the Menzenschwand valley are even more striking. The ''Menzenschwander Kluse'' is a well-known

terminal moraine A terminal moraine, also called an end moraine, is a type of moraine that forms at the terminal (edge) of a glacier, marking its maximum advance. At this point, debris that has accumulated by plucking and abrasion, has been pushed by the front e ...

. Below the Kluse, the Menzenschwand Alb plunges with several waterfalls through a small ravine to a basin created by the former Krunkelbach valley glacier.

Middle reaches

The area occupied by the municipality of Sankt Blasien's area is dominated by the

classicist Classics, also classical studies or Ancient Greek and Roman studies, is the study of classical antiquity. In the Western world, ''classics'' traditionally refers to the study of Ancient Greek literature, Ancient Greek and Roman literature and ...

dome of Sankt Blasien's

Cathedral A cathedral is a church (building), church that contains the of a bishop, thus serving as the central church of a diocese, Annual conferences within Methodism, conference, or episcopate. Churches with the function of "cathedral" are usually s ...

. Below the village centre, the Alb form a waterfall, locally known as , after the Roman town of

Tusculum Tusculum is a ruined Classical Rome, Roman city in the Alban Hills, in the Latium region of Italy. Tusculum was most famous in Roman times for the many great and luxurious patrician country villas sited close to the city, yet a comfortable dist ...

. The Alb, like most rivers in this part of the Black Forest, then changes its course by about 60 degrees, towards the south. This is thought to be caused by

tectonic Tectonics ( via Latin ) are the processes that result in the structure and properties of the Earth's crust and its evolution through time. The field of ''planetary tectonics'' extends the concept to other planets and moons. These processes ...

movements of the Earth's crust, which have increased the

gradient In vector calculus, the gradient of a scalar-valued differentiable function f of several variables is the vector field (or vector-valued function) \nabla f whose value at a point p gives the direction and the rate of fastest increase. The g ...

to the

. The only valley that continues in a south-eastern direction is about higher, in the saddle near Häusern. During the ice age, the Alb glacier was about high in this area, and its meltwater overflowed the Häusern saddle, into the Schwarza valley. Below this bend, the Alb water is collected in a

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

, the Alb Basin. Its average surface area is ; it is impounded by a dam of about in length. Most of the water is piped to the '' Schwarzabruck'' reservoir. Both reservoirs are owned by the Schluchseewerk AG. The Alb then flows through a wide valley, lined by meadows, which contains the villages of Schlageter and Immeneich. The valley is no longer bordered by narrow, wooded ridges, but instead by the undulating Hotzenwald plateau in the municipalities of Dachsberg und Höchenschwand. The plateau is indented by bogs and rocky hilltops. During the Würm ice age, the Alb glacier ended at the point where we now find the village of ''Niedermühle''. With a length of , the Alb glacier was the longest in the Black Forest. Downstream of Niedermühle, the valley is very narrow, leaving no room for settlements.

Alb Gorge

The slope of the Alps increased greatly in the ravines and the river forces its way through the more canyon-like passages and blocked sections known as the ("Devil's Kitchen"). The Ibach and Höllbach join from the right, each emerging from its own narrow gorge. The Höllbach has two waterfalls in this area. Because the gorge is so narrow, the road is up to higher, on the left bank. On a wider spot in the valley, is the saw mill ''Tiefenstein'' and two tributaries, Schildbach and Steinbach. Halfway up the slope, there are granite quarries and the ruins of two castles. The narrowest and most dangerous passage begins downstream of Tiefenstein. Long ago, the Alb followed a different course and flowed to Hauenstein through the valley now occupied by the Mühlbach. This route was blocked by glacial deposits during an earlier ice age, forcing the Alb to find a new route to the Rhine. Since then, the "new" gorge cuts through the granite rock. This section cannot be travelled without special equipment, even though the water flow is usually low, because most of the water has been diverted. It there is sufficient water,

canoeing Canoeing is an activity which involves paddling a canoe with a single-bladed paddle. In some parts of Europe, canoeing refers to both canoeing and kayaking, with a canoe being called an 'open canoe' or Canadian. A few of the recreational ...

is possible, although this is considered the most difficult stretch of

whitewater Whitewater forms in the context of rapids, in particular, when a river's Stream gradient, gradient changes enough to generate so much turbulence that air is trapped within the water. This forms an unstable current that foam, froths, making t ...

in Germany.Josef Haas: ''Wildwasserperlen'', Constance, 1980, p. 25 In this section the road runs up to above the river and passes through five short tunnels drilled through the cliffs, giving it the nickname "Axenstraße of the Black Forest". From the hamlet ''Hohenfels'', the road descends to the valley floor at Albbruck, where the Alb flows into the High Rhine.

Gallery

File: Menzenschwand 7688.jpg , Waterfalls in the gorge of Menzenschwander Alb File: Herzogenhorn in Richtung Bernau.jpg , The valley north of Bernauer Alb File: St Blasien 1900.jpg , St Blaise and the upper Alb valley in 1900 File: StBlasienFluss.jpg , The Alb in St. Blasien File: AlbStausee.jpg , The Albbecken below St. Blasien File: AlbNiedermuehle.jpg , The Alb valley above the gorge at ''Niedermühle'' File: AlbTiefenstein.jpg , Widening of the Alb gorge at Tiefenstein File: Albtaltunnel.jpg , One of the five tunnels in the upper canyon wall

Footnotes