A large number of polluters have been registered across Vojvodina. Industrial pollution is the most dominant, followed by pollution from agriculture and livestock production, as well as pollution originating from settlements. Additional pressure comes from many smaller sources — villages without sewage systems, agricultural land, and small livestock farms.

Many polluters do not treat their wastewater at all. Some treat it together with municipal wastewater, some only use mechanical treatment, while only a small number implement biological treatment. All of this directly affects the water quality of the Tisa River.

Deterioration of Water Quality

In recent years, the water quality of the Tisa has become a serious concern for the population of the Potisje region. It angers anglers, troubles experts, and demands urgent ecological attention. Even this wide, calm Vojvodina river cannot withstand continuous pollution — the water, plants, and animal life are visibly changing.

People still remember the days when the Tisa “bloomed,” when its water was used for drinking, and when fish soup was cooked using water taken directly from the river. Today, the Tisa is increasingly becoming a collector of wastewater, and its ecosystem is in decline.

Biological analyses show a significant deterioration compared to previous years. Several factors contribute to this, and according to biologists, the most important include:

• inflow of polluted waters from abroad,
• polluted waters discharged by domestic polluters along the river and from the DTD canal system,
• long-lasting droughts in recent years,
• reduced water flow caused by the Tisa Dam near Novi Bečej.

Main Sources of Pollution

1. Inflow from Abroad

Experts estimate that around 75% of the pollution originates outside the country. Efforts are being made to renew trilateral cooperation between Serbia, Hungary, and Romania to protect and rehabilitate the Tisa River. However, without substantial changes upstream, major improvements are unlikely.

2. Domestic Polluters and the DTD Canal System

Domestic pollution is also significant. Industrial facilities in Novi Kneževac and Senta, as well as pollutants entering through the Bački Veliki Canal (Crvenka, Vrbas, Srbobran), further burden the Tisa and negatively affect its ecological condition.

3. Droughts

Prolonged droughts lead to reduced water inflow, which means weaker dilution of pollutants. This results in sudden drops in oxygen and increased concentrations of harmful organic substances. Such conditions often cause mass deaths of fish and other aquatic organisms.

4. Impact of the Dam near Novi Bečej

The Tisa Dam slows the natural water flow, and since its construction, analyses show that the Tisa has increasingly taken on the characteristics of standing water. This favors the growth of algae and accelerates ecological degradation.

Duckweed Bloom and River Overgrowth

In recent years, during mid-summer, the Tisa becomes almost completely covered by green duckweed within a very short time. Although it arrives from Hungary, it is widespread in local stagnant waters as well.

Because duckweed prevents proper oxygen exchange between air and water, oxygen levels drop drastically, causing severe consequences for aquatic life. Other floating plants also appear, creating problems for swimmers, anglers, and everyone who uses the river, while disrupting the pleasant riverfront environment.

Ecological Indicators and the Disappearance of the Tisa “Bloom”

Analyses confirm a clear deterioration of water quality. Microorganisms and species that indicate a healthy ecosystem are becoming less common. Noble fish species characteristic of the Tisa are disappearing, and the once-famous natural phenomenon — the spectacular “blooming” of the Tisa, caused by the mass emergence of the mayfly — has completely vanished.

Today, the Tisa’s water is mostly classified as Class III, often on the border between Class II and Class III, and occasionally even Class IV during periods of severe pollution.

Efforts to Protect the River

Biologists, ecologists, and environmental activists are putting tremendous effort into saving the Tisa. The goal is to restore the river to Class I or Class II and allow its ecosystem to recover. Active participation of local residents is essential for long-term improvement.

Navigation and Transport

The total length of navigable canals within the primary canal network is about 600 km. These canals allow the passage of cargo vessels with a capacity of 200 to 1,000 tons. Along the canal banks, there are docking points for loading and unloading goods, including several in Novi Bečej. Some berths are equipped with storage facilities and loading machinery.

Until 1979, the volume of transported goods steadily increased, after which a noticeable decline began.

River–canal transport requires substantial investment and long-term planning, as the commissioning process is lengthy and complex.

Navigation on the Kikinda Canal has been active since 1975, while berths were constructed somewhat later — in 1977.