Lake Ruda Woda (; ) is a long freshwater ribbon lake in Powiśle region in northern Poland. The lake lies entirely within Gmina Małdyty in Warmian-Masurian Voivodeship and is an integral part of the Elbląg Canal. Stretching in length, the lake features four distinct bays and several islands. The lakebed is diverse, with numerous depressions and shallows. Shores are mostly high and steep, surrounded by temperate deciduous forest, with only the southern and northern parts bordered by fields and meadows.
Lake’s surroundings are sparsely populated with several villages located nearby, including Wilamowo, Szymonowo, Szymonówko, Sople and Liksajny.
The lake provides fishing and recreation opportunities, including sailing, kayaking and jet skiing. Several public piers scatter around the lake facility access to convenient entry points for swimming and sunbathing. Scouting camp is located in the northern part of the lake.
Name
The name "Ruda Woda" (literally meaning "red/rusty water") was assigned in 1950 by the Polish Commission for the Determination of Place Names. The commission, which operated after World War II under the Ministry of Public Administration, was tasked with creating toponyms for locations, villages, towns, and cities in the former eastern territories of Germany.
One of the earliest preserved mentions of the original German name of the lake—Röthloff (or Roethloff) See —appears in 16th-century historical documents, although the name must have been in use much earlier. The name Röthloff is found in a document from the Teutonic Order dated 1522, in which Grand Master Albert granted fishing rights on Lake Röthloff to brothers Paul and Wolf Fasolt from Iława. This name also appears on a 16th-century map of the Oberland region of Prussia by Caspar Henneberg from 1576.
The etymology of the name Röthloff See is not precisely known. The name may derive from the German surname Rothloff or many of its variants including Ruttloff, Rutlaf, Roltloff, and Rotleff. Notably, the first part of the name can be traced to the Old Germanic word "rot," meaning red, which influenced the Polish name given after World War II.
An unofficial but commonly used name for the lake is "Lake Duckie / Dudzkie" (IPA: dut͡skʲɛ). This name originates from the Ducki Canal (German: Dutzkanal), which links Lake Ruda Woda to Lake Bartężek, located to the southeast.
Geography and hydrography Geological history
Lake Ruda Woda is an example of a ribbon lake formed in central Europe during the final phase of the most recent glaciation, approximately 14,000-12,000 years ago. As rivers flowed beneath the retreating glacier, they encountered softer rock, carving out deep channels known as glacial troughs. With the warming climate, blocks of dead ice melted, leaving behind long, narrow, and relatively deep lakes. The chain of lakes, including Sambód, Ruda Woda, Ilińsk, and Drwęckie, reflects the course of the local post-glacial trough. The melting glacier deposited layers of clay, sand, and gravel and created sequences of moraine hills, which are visible in the southern part of the lake.
Geography Ruda Woda Lake is located in northern Poland, within the macroregion of the Pojezierze Iławskie (Iława Lake District), which is ethnographically classified as part of the Powiśle region. Historically, this area belonged to the German province of Upper Prussia (German: Oberland). The region is sometimes mistakenly considered part of Masuria, specifically the Western Masuria, which is neither a distinct geographic nor ethnographic region but rather a tourist brandAgata Michalak, Przemysław Charzyński, Report on the Analysis of the Tourist and Cultural Potential of the Ostróda County, Cultural Tourism, Vol 4, No 125 (2022)
Morphometry and morphology
The long and narrow lake runs in a north-south direction, and its course is characterized by numerous bends. The total length of the lake, measured along the centerline, is , with an average width of only . At its widest point, the lake measures . While historical sources often list the lake's area as —a figure that continues to be incorrectly cited— modern government topographic maps show it as .The Topographic Objects Database (BDOT10k) Ruda Woda gmlID = id_2D260B95-C19F-9D6A-E053-CC2BA8C0F6D6 The coastline is long.
Two distinct, noticeably shallower bays can be found to the east and west of the main body of water. The western bay near the village of Sople contains three small islands. On the opposite shore of the western bay, where the former site once served to store and prepare wood for rafting, a scout camp has been established. The camp hosts annual sailing and scouting events. The eastern bay, known as Zatoka Drela (Drela Bay) or Żydowski Kąt (Jewish Corner), is where the lake's main tributary, the Drela River (German: Drehle), flows in. The name Żydowski Kąt (Jewish Corner) originates from wartime stories among the local population, which claim that the Jewish owner of a nearby inn and his family were drowned in the lake. Stretching to the southeast, Drela Bay, together with the lake's main route, forms a peninsula known as Stańkowo. In the southern part of the lake, two small bays extend northwest, where the village of Liksajny is located. The lake features seven uninhabited islands, the largest of which is situated in the northern part, opposite the village of Wilamowo.
Besides the Drela River, the lake is fed by smaller, unnamed tributaries that dry up seasonally. The largest of these are located near the villages of Wilamowo and Sople. Ruda Woda Lake is connected by the Elbląg Canal to Lake Rakówka (German: Krebs) and then Ilińsk to the south, and to Lake Sambród to the north. At the four-kilometer mark (counting from the southern end) on the eastern shore, there is an entrance to the Ducki Canal, which connects Ruda Woda Lake with Lake Bartężek (German: Bärting See) to the southeast.
Bathymetry
The floor of Lake Ruda Woda is typical of lakes formed by rivers eroding the substrate under a glacier. The varying pressure from the ice caused the rivers to carve the lakebed in different directions, creating numerous depressions and shallows.
The lake has an average depth of , however, its depth varies significantly from north to south. In the northern part, the average depth is , increasing to about in the central area near Drela Bay, and reaching approximately meters in the southern section. The southern end of the lake becomes much shallower before it flows into the Elbląg CanalJ. Waluga, H. Chmielewski, 1997 - Jeziora okolic Olsztyna. Przewodnik Wędkarski (2). Wyd. IRS, s. 139-143
The depth gradient is further highlighted by the fact that all the islands are situated in the shallower northern part of the lake. This region also features a prominent shoal extending toward the lake's center, across from the village of Wilamowo. In contrast, the lake reaches its greatest depth about from the southern end, near the village of Szymonówko, where it drops to more than below the surface.
History and economy
Settlement history
The lake is located in the historic region of Pogezania, inhabited from the 5th to the 9th century by Prussian tribes—Baltic peoples who spoke an Indo-European language of the Baltic branch. Many names of the villages situated around the lake may derive from the Old Prussian language, such as Małdyty, Ględy, Bartężek, and Sople.„Morąg – z dziejów miasta i powiatu”, Pojezierze, Olsztyn 1973.Baltic Onyms in Time and Space, G. Blažienė, Indo-European linguistics and classical philology, 2021, 25 (1), p. 69-98, DOI: 10.30842/ielcp230690152504
These lands became the target of conquest by the Teutonic Order from the 13th century onwards, having been brought to the region by Konrad I of Masovia. Teutonic colonization was part of a broader christianization campaign of the Northern European peoples, aimed at imposing Scandinavian and German rule, known as the Northern Crusades.
The Teutonic Order brought settlers from German-speaking countries to these areas. During this time, the villages of Wilamowo (1308), Szymonowo (1324), Liksajny (1325), Wenecja (1336), Bartężek (1340) and Czulpa (1345) were founded. The pace of German colonization slowed with the crisis and decline of the Teutonic state. After the Second Peace of Thorn in 1466, there was an increasing influx of Polish settlers, peaking in the 17th and 18th centuries.
The population growth accelerated in the 19th century, supported by the region's economic development, exemplified by the construction of the Oberland Canal, with Lake Ruda Woda becoming its longest natural section.
After World War II, the province of East Prussia ceased to exist, and the areas where the lake is located were incorporated into Poland. Due to expulsions and relocations, these areas became predominantly Polish.
Construction of the Oberland Canal
In 1844, the construction of the Oberland Canal began, aiming to connect the lakes of Oberland (Lake Jeziorak and Lake Drwęca) with Lake Drużno near Elbląg, and ultimately with the Vistula River and the Baltic Sea. The canal was designed to stimulate the economic development of towns and villages in East Prussia, which, during the Industrial Revolution, required both raw materials for emerging industries and a way to market their natural resources, mainly grain and timber. The canal was constructed by the engineer Georg Jakob Steenke, who resided in Czulpa on Lake Ruda Woda.
The construction of the canal was a massive hydrotechnical undertaking, fundamentally impacting lake's morphometry, which was the longest natural section of the emerging waterway. The difference in elevation between the water level of Lake Drużno, where the route begins, and Lake Jeziorak, where it ends, was . The water levels of the lakes along the canal's route were equalized to meet of those of Lake Jeziorak (). Before the lowering, Lake Ruda Woda’s surface was at an elevation of . As a result of the canal's construction, its water level dropped by over . Consequently, its original area became almost 8.5% smaller.G.J.Steenke, Zusammebsteellung der Nivellements und Pilotements im Preußischen Oberlande inden Jahren 1842 – 1844 ausgeführt vom Ober-Wasserbau-Inspektor Steenke”, Neue Preußische Provinzial-Bl.tter, Tom V, Königsberg 1848 The excess water from the lowered lake was drained into Lake Drwęckie, and then through the Drwęca River to the Vistula River and the Baltic Sea.Bernhard Ohlert, “Slizzen aus Alt-Preußen, Der oberländische Kanal”, Altpreußische Monatsschrift zum Spiegelung des provinziellen Lebens in herausgegeben, Königsberg 1864 Bernhard Ohlert's account of his multi-day expedition along the Oberland Canal in 1862 describes the consequences of the lowered water level in Lake Ruda Woda. Ohlert noted:
The opposite shore [of lake Ruda Woda] presents a peculiar appearance. In front of the forest crown covered with tall, old trees, there is a much lower, differently colored strip of young growth, which obviously emerged only after the partial draining of the lake basin. Curiously, it consists almost exclusively of alders, whereas in the high forest behind it, the alder is only sporadically present.
The hydrological work related to the canal's construction also led to the drying up of Lake Naświty (German: Nasewittsee), which was connected to Lake Ruda Woda and located northeast of it. This occurred despite Steenke's plan to use Lake Naświty to connect Lake Ruda Woda with Lake Morąg, and ultimately with Morąg.
Transportation
before the 20th century