Bällstaån or Spångaån ( Swedish: "Stream of Bällsta/Spånga") is a small

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a strea ...

in northern

Stockholm Stockholm (; ) is the Capital city, capital and List of urban areas in Sweden by population, most populous city of Sweden, as well as the List of urban areas in the Nordic countries, largest urban area in the Nordic countries. Approximately ...

. Flowing through the municipalities of Järfälla, Stockholm,

Sundbyberg Sundbyberg Municipality ( or ''Sundbybergs stad'') is a municipality in Stockholm County in east central Sweden, just north of the capital Stockholm. Sundbyberg is wholly within the Stockholm urban area and has a 100% urban population. Sundbybe ...

, and

Solna Solna ( or , ), also known as Solna Municipality, is a municipality in central Stockholm County, Sweden, located just north of Stockholm City Centre. Its seat is located in the town of Solna, which is a part of the Stockholm urban area. Solna i ...

, it empties in the bay Bällstaviken, the innermost part of Ulvsundasjön. Some 1,4 km of the stream is passing through culverts and long stretches of it have been straitened out to form part of the local stormwater system. Notwithstanding, other sections are furnished with promenades and ponds and therefore considered as of local recreational interest. The municipalities sharing the catchment area, together with the county administrative board, are collaborating to improve water quality and the areas surrounding the stream.Bällstaån

Catchment area

Flowing from

Viksjö Viksjö () is a district of Järfälla Municipality, Stockholm County, Sweden, in Stockholm Stockholm (; ) is the Capital city, capital and List of urban areas in Sweden by population, most populous city of Sweden, as well as the List of u ...

in Järfälla, the stream starts as a ditch receiving considerable amounts of stormwater from the residential area

Jakobsberg Jakobsberg is a suburban area (pop. ca 32 643 in the year 2022) within Stockholm urban area, and the seat of Järfälla Municipality, Stockholm County in Sweden. Jakobsberg, Järfälla's commercial and administrative centre, grew up around ...

. After a bit more than 2 km, near Barkarby Airport, it dives into a short culvert before merging with another ditch (''Veddsta dike'') bringing water from a golf range, industrial and residential areas. It then passes under the traffic route E18 to continue 1 km through am open grassland in it natural meandering shape past some allotment-gardens near

Tensta Tensta is a district in Spånga-Tensta, Spånga-Tensta borough, Stockholm, Sweden. There are about 6,000 apartments in Tensta and a population of 18,637 as of December 31, 2022. Modern Tensta, with its Plattenbau-style concrete apartment bu ...

before reaching the ponds in the park of Hjulsta. The stream is guided under the central commercial district of Spånga through a tunnel 1.4 km long, opening out near Bromsten industrial area, and receiving stormwater from surrounding areas. It then flows past the residential neighbourhood Bällsta before reaching two ponds in a park and receiving water from a second ditch (Nälsta dike) bringing water from residential areas at Nälsta, Flysta, and Solhem. It then flows through the

harness racing Harness racing is a form of horse racing in which the horses race at a specific gait (a trot or a pace). They usually pull a two-wheeled cart called a sulky, spider, or chariot occupied by a driver. In Europe, and less frequently in Australia ...

track Solvalla where the water is used for fountains during races. Downstream Solvalla, it becomes broad with a slow flow occasionally becoming stagnant. Bällstaån finally receives water from Rissne,

Duvbo Duvbo is a residential area in Sundbyberg in suburban Stockholm, Sweden. In 2019 it had 2217 inhabitants. The Duvbo metro station is located in central Sundbyberg Central Sundbyberg () is the oldest and longest-established part of Sundbyberg M ...

, and

before emptying into Bällstaviken under the bridge Löfströmsbron.Vattenprogram, 29.3-4

Environmental influence

As most of the inflow comes from settled grounds, including industrial areas and streets, the stream contains high levels of nutrients, metals and bacteria, with sediments contaminated with oil. The river receives 1400 kg/year of

phosphorus Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...

and 16000 kg/year of

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

. Increased levels of pollutants and bacteria downstream Spånga is believed to stem from stormwater pipes but no source have been identified. Increased levels of metals, particularly copper, has been reported, and minor oil discharges are rather common with negative impact on local bird life.

Flora and fauna

No inventory of

aquatic plant Aquatic plants, also referred to as hydrophytes, are vascular plants and Non-vascular plant, non-vascular plants that have adapted to live in aquatic ecosystem, aquatic environments (marine ecosystem, saltwater or freshwater ecosystem, freshwater ...

s has been made, but greater dodder has been documented around the Lunda Industrial Area. No rare species of bottom fauna were found during an inventory in 1999, the stream being quantitatively dominated by a few species. Noteworthy is the gastropod ''

Valvata piscinalis ''Valvata piscinalis'', common name the European stream valvata or European valve snail, is a species of small freshwater snail with gills and an operculum, an aquatic gastropod mollusk in the family Valvatidae, the valve snails. It is also kn ...

'' found near the residential area Bällsta. The stream is, nonetheless, important for various birds, including

black-headed gull The black-headed gull (''Chroicocephalus ridibundus'') is a small gull that breeds in much of the Palearctic in Europe and Asia, and also locally in smaller numbers in coastal eastern Canada. Most of the population is migratory and winters fu ...

common gull The common gull (''Larus canus'') is a medium-sized gull that breeds in cool temperate regions of the Palearctic from Iceland and Scotland east to Kamchatka in the Russian Far East. Most common gulls bird migration, migrate further south in wint ...

lesser black-backed gull The lesser black-backed gull (''Larus fuscus'') is a large gull that breeds on the Atlantic coasts of Europe. It is migratory, wintering from the British Isles south to West Africa. However, it has increased dramatically in North America, especi ...

herring gull Herring gull is a common name for several birds in the genus ''Larus'', all formerly treated as a single species. Three species are still combined in some taxonomies: * American herring gull (''Larus smithsonianus'') - North America * European h ...

, and Slavonian grebe reported at Hjulsta Water Park. As stretches of the watercourse remain ice-free during winters, it attracts

duck Duck is the common name for numerous species of waterfowl in the family (biology), family Anatidae. Ducks are generally smaller and shorter-necked than swans and goose, geese, which are members of the same family. Divided among several subfam ...

s and

teal alt=American teal duck (male), Green-winged teal (male) Teal is a greenish-blue color. Its name comes from that of a bird—the Eurasian teal (''Anas crecca'')—which presents a similarly colored stripe on its head. The word is often used ...

, which have both been spending winters here.Vattenprogram, p 29.5-6

Notes

References

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External links