Water intake built structure

WATER INTAKE BUILT STRUCTURE, water intake (EN: water inlet, water intake works; DE: Wasserentnahmestelle, Wasserfassung; FR: prise d'eau, installation de prise d'eau; ES: toma de agua; RU: водозаборное сооружение), is the hydrotechnic built structure for the intake of the water from the water body, watercourse, or underground water source, for the purpose of the industrial and household-domestic water supply.

They distinguish the water intake built structures for the superficial and underground waters. The water intake built structures for the superficial waters are divided into the water inlets of the coastal type, which are positioned on the slope, and pump the water out using the pumps through the suction pipes immediately from the channel, and the water inlets of the channel type, which comprise the receiving head within the channel of the river, from where the water through the free-flow lines arrives into the coastal water well, and is pumped out further using the pump. For the intake of the underground waters, there are used the vertical (boreholes, underground mine wells), horizontal (trenched and piped water intake built structures, galleries, adits, kyarizes, namely, the combinations of the adits and underground mine wells), and radial water intake built structures, and the catchments for the water spring sources. The most widespread water intake built structures are the drilled boreholes, which are used for the intake of the underground waters under the diverse conditions, and are characterized by the best sanitary situation.

In case of the unsealing of the water-containing loose rocks, the water inlet part of the borehole is equipped with the special filter. In those cases, when the water-containing loose rocks are overlain with the stable roof, there are constructed the so-called boreholes without the filter, within the water inlet part of which there is artificially created the cavity. Within the stable rocky rocks, they install the perforated pipes instead of the special filters. The depth of the water intake boreholes varies from the first tens of metres up to 1000 metres and more; the diameter of the water inlet part varies from 100 to 600 millimetres; the performance reaches several thousands cubic metres per day. The water intake built structures of the borehole type are used for all cases, when it is expedient to operate several aquifers. Usually, there are created for the centralized water supply systems the grouped water intake built structures, which are comprising the big quantity of the b oreholes (tens, sometimes hundreds). They pump out the water from the borehole using the superficial (in case of the depth of the water level of up to 7-10 metres) or submersible pumps, and also using the air-lift installations. The underground mine wells are used, as a rule, for the water intake from the first, counting from the surface, non-pressurized aquifers, which are formed of the loose rocks with the comparatively limited thickness (up to 10-20 metres).

Within the weakly water-abundant layers, when it is impossible to perform the water intake from the boreholes, they construct the underground mine wells also within the pressurized aquifers, with their depth of the embedment of up to 30-40 metres below the surface. The horizontal water intake built structures are constructed for the intake of the water from the non-pressurized horizons of the small thickness. The radial water intake built structures represent by themselves the water collecting underground mine wells with the impermeable walls, into which the water is collected through the divergent horizontal rays-boreholes (drains). They use the radial water intake built structures for the shallowly embedded (up to 15-20 metres) aquifers with the small thickness (5-10 metres); their usage is most expedient within the valleys of the rivers with the constant runoff, where the boreholes pass immediately under the channel of the river.

The peculiar type of the water intake is the catchment of the water spring sources, which is constructed under the conditions of the concentrated yield of the waters onto the surface in the form of the chambers or shallow wells.

The water intakes for the underground waters, which are situated within the regions of the development of the deposits of the useful minerals, besides the water supply role, perform the role of the built structures for the drainage and lowering of the water level, which are decreasing the inflows of the water into the mine workings. The calculations of the performance for the water intake built structures for the extraction of the underground waters, are the major element of the evaluation of the operational reserves of the underground waters, and are conducted according to the formulas of the dynamics of the underground waters, the selection of which depends on the hydrogeological conditions, and on the type of the built structure. Under the complicated hydrogeological conditions, there is used for these purposes the mathematical modeling with the usage of the computers.