Somes-Tisa Watershed Area

Somes-Tisa watershed area is located to the North and North-Western part of the country, being delineated to the North by the natural border – Tisa river with Ukraine on a length of 61 km, to the West by the border with the Hungarian Republic, and on the national territory, it borders on Siret Basin to the East, Mures Basin to the South and Crisuri Basin to the South-West.

Where is it located?

In administrative terms, Somes-Tisa watershed area includes the territory of 7 counties, respectively: Cluj, Salaj, Bistrita-Nasaud, Maramures, Satu Mare, Alba and Bihor. The ratio of the last two is insignificant. The total population is of around 1.95 million inhabitants, the population density being of 87.03 inhabitants/km2.

On the Romanian territory, Somes-Tisa watershed area includes the sub-basin of Tisa (including Turul) with 123 coded water courses (an area of 4540 km2 and the network density of 0.35 km/km2), Somes with 403 coded water courses (an area of 15740 km2 and the network density of 0.35 km/km2) and Crasna with 54 coded water courses (an area of 2100 km2 and the network of 0.34 km/km2). The total water resources of surface water in Somes-Tisa watershed area amount to approx. 6830 mil. m3/year, of which, usable resources are of approx. 1287 mil. m3/year. In Somes-Tisa watershed area, there are 8 important reservoirs (with an area of more 0.5 km2), of complex use and totaling a useful volume of 328.3 mil. m3.

Total water resources

The total area of Somes-Tisa watershed area is of 22451.86 km2, representing a ratio of 9.42% of the country area. The hydrographic network includes 580 surveyed water courses (of which 46 have river basins with an area of less than 10 km2), with a total length of 8387 km and an average density of 0.37 km/km2.

On the Romanian territory, Somes-Tisa watershed area includes the sub-basin of Tisa (including Tur) with 123 coded water courses (an area of 4540 km2 and a network density of 0.35 km/km2), Somes with 403 coded water courses (an area of 15740 km2 and a network density of 0.35 km/km2) and Crasna with 54 coded water courses (an area of 2100 km2 and a network area of 0.34 km/km2). The total surface water resources in Somes-Tisa watershed area amount to approx. 6830 mil. m3/year, of which usable resources are of approx. 1287 mil. m3/year. In Somes-Tisa watershed area, there are 8 major reservoirs (with an area of more than 0.5 km2), of complex use and totaling a useful volume of 328.3 mil. m3.

The average multiannual discharges for the main rivers in Somes-Tisa watershed area are: 130 m3/s (Tisa river when exiting the country), 129 m3/s (Somes river in Satu Mare gauge station), 5.83 m3/s (Crasna river in Domanesti station).

Description of existing flood protection works

A major role in the flood protection is played by the 10 permanent reservoirs (Colibita, Fantanele, Tarnita, Somesul Cald, Gilau, Varsolt, Stramtori, Calinesti, Salatig and Hodisa), by the 5 self-managed non-permanent reservoirs (Cuceu , Borlesti, Crucisor, Hodos and Tamaseni), 2 self-managed polders (Moftin and Supur), as well as 99 reservoirs of category C and D. Permanent reservoirs have a total alleviation volume of over 120 million of m3. At the level of Somes-Tisa watershed area, there are 135 embankment works with an average height of dikes of around 1.9-2 m and a total length of around 767.91 km.

Structural measurements refer to investment works for making safe the existing ones and for bringing them to the performance parameters stipulated in the Defense Strategy, as well as new investment works both on water courses and on areas of sub-basins making up Somes-Tisa watershed area. The main existing works considered for making them safe are reservoirs and embankment works, especially those defending important socio-economic and administrative centers.

Flood records

The maximum quantities of precipitations are recorded during spring-summer, in particular during the period March-June and in August. One can remember several maximum historical values of precipitations occurred during serious floods across the entire river basin as those recorded in May 1970 (over 150 mm/24 hours and even 200 mm/24 hours in Baia Sprie).

Serious floods, with significant maximum discharges, come from rainfalls recorded on large areas of the basin or from mixed source (snowmelt and rain). The maximum historical flood over the last 50-60 years was that occurred in 1970, having a mixed source. An analysis of the series of floods over around the last 50 years shows that the most significant floods occurred in: 1970, 1974, 1975, 1978, 1979, 1980, 1981, 1989, 1993, 1995, 1998, 2000, 2001, 2005 and 2008.

The first half of 1970 was characterized by catastrophic floods. The most serious floods occurred on the rivers Somes, Tisa, Tur, Viseu, Iza, Lapus, Sieu, Crasna, Almas, Somesul Mic and their tributaries. Discharges exceeding the insurance of 1% were recorded on the rivers Somes (downstream Dej) and Viseu, on the other water courses, there were discharges recorded with the insurance ranging between 5– 10%. There was a breach of dikes on rivers Somes and Tur (Satu Mare county), which caused the flooding of many urban and rural localities. Floods were caused by long-lasting heavy rainfalls accompanied by snowmelt resulting in floods that exceeded the flood level, on most rivers in Somes-Tisa river basin. Important urban localities were affected, such as Nasaud, Beclean, Gherla, Dej, Zalau, Jibou, Simleu, Satu Mare, as well as many rural localities (over 200).

Contact Somes – Tisa ABA

Address: Str. Vânătorului ,Nr.17, C.P. 400213, Cluj-Napoca, ROMÂNIA

Dispatcher’s Office: Somes-Tisa RBA

Tel: +40 264 433028 , Fax: +40 264 433026

E-mail: apecj@dast.rowater.ro

Relations with the press: presa@dast.rowater.ro

Website: ABA Someș-Tisa