The major part of the tundra rivers can be nominally divided into lowland rivers and mountain rivers. For lowland rivers are characterized by small gradient, lake-like openings, river reaches and stepped sites, rifts. Due to great amount of lakes of different size some rivers are like lake-river systems. Umba river, for example, by fifty percent of its flow takes water from the lakes. The average speed of the flow at a deep water river stretch is small, usually one-two tenth of the meter per second, at low water rapids site it sometimes increases up to one meter per second.
Large slopes and speeds are peculiar of mountain rivers. For example, the average slope of Malaya Belaya river, flowing from Maly Vud'javr is about thirty meters per one kilometer that is four times higher that Ponoi river slope.
The rivers of the Khibiny flow among solid rocks that are almost not exposed to leaching and washing and among boulder-gravel-sandy loam and sandy deposits consisting of clastic pieces of crystalline rocks' disturbance having place for a long period of geological time. Solids parts washed by the water are sedimented in the lake-like openings and lakes. Therefore, the river water is a fresh water, share of dissolved salts content is less of fifty-hundred milligram per liter, largely, clear and pure. In many cases it is similar to atmospheric precipitation by its chemical composition: it is mainly sodium-hydrocarbonate, calcium- sodium, near the seas - sodium chloride - due to sea salts inwash by precipitation. River water has a weakly acid and neutral reaction. It should be noted that water of some rivers is not pure enough that is determined by the discharge of contaminated waste waters, precipitation inwash with dust and gas emissions of industrial enterprises and afflux of significant amount of swamp water.
Low content of dissolved salts in the river water, especially calcium salts makes it impossible to use as a drinking water, river contamination has a negative impact on the ecosystems and the quality of drinking water.
During the year the content of various admixtures in the river water is changing, it increases during spring time when the dust, sand and other substances get into the rivers with the melt water. Contaminated by waste water , rivers have a high content of admixtures even in winter as during this period dilution of waste water is abruptly decreased in the river water.
In all water entities the water is primarily melt water, i.e., snow water, therefore, they are noticeable rapid spring flood flow.
In October the rivers start to freeze, but firm and hard crust keeps practically six-seven months. Ice thickness depends on the air temperature and winter season duration. It can be six-eight tenth meter or even more than one meter during some winters in the river pools. However, in the riverheads where they flow from the lakes at rapid flow sites, intense inflow of underground or warm waste water, during hard frosts there appear open water or thin ice, being a hazard to travelers.
River break-up starts in spring, in May. It is accompanied by ice blocking and spring ice drift. The largest ice blocking are observed in the Ponoi river mouth.
Average temperature of the water in the rivers of the region in July is equal to thirteen-sixteen Centigrade. Rarely, during especially warm years it does not exceed twenty-twenty-two Centigrade.
The amount of water taken by the rivers from the definite territory during the year is considered its water supplies; supplies are restored annually during the water cycle on the planet. Water supplies include natural resources of underground waters as a large territory the underground water almost entirely inflow into local river network.
Water resources of the Khibiny are local, forming within the territory. The amount of water resources in the region is changing depending on precipitation amount and its evaporation. The higher amount of precipitation and less its evaporation, the higher amount of water resources and vice versa, the less precipitation and higher evaporation, the less amount of water resources. The rivers of Murmansk region carry out about sixty percent of water volume into the White and Barents Seas as precipitation. Nowadays it is more than fifty thousand of square meters of water account for inhabitant annually.