Aquifers of the city of Kyiv

The ter­ri­to­ry of the city of Kyiv and its sur­round­ing areas is locat­ed at the junc­tion of three oro­graph­ic regions: the Dnieper upland, the Pole­sian low­land, and the Dnieper low­land.

The cen­tral and south­west­ern parts of the city are sit­u­at­ed with­in the Dnieper upland, which gen­tly slopes west­ward and is cov­ered at the sur­face by rocks of the loess for­ma­tion. Its high­est ele­va­tions range from 170–175 m (Vysh­horod, Lukian­iv­ka) to 190–198 m (Bati­ie­va Hora, Pech­er­sk, Zvirynets). These areas are char­ac­ter­ized by deep and dense ero­sion­al dis­sec­tion, with ero­sion inci­sion depths exceed­ing 80 m. Sig­nif­i­cant ver­ti­cal dis­sec­tion is char­ac­ter­is­tic of the right bank of the Dnipro riv­er along the sec­tion from Vit­ri­ani Hory to Tely­ch­ka, as well as in Sovky and Teremky. Water­sheds are rep­re­sent­ed by small iso­lat­ed rem­nants of the plain con­cen­trat­ed with­in the inter­fluve area between the Dnipro and the Lybid riv­er. Mov­ing west­ward away from the Dnipro riv­er, the degree of sur­face dis­sec­tion decreas­es, while the area of flat and weak­ly dis­sect­ed plain sur­faces increas­es.

The north­ern and north­west­ern parts of the city are locat­ed with­in the Pole­sian low­land and rep­re­sent a slight­ly hilly moraine-san­dur plain. Its sur­face is char­ac­ter­ized by ele­va­tions of 140–190 m and minor hor­i­zon­tal and ver­ti­cal dis­sec­tion. The east­ern (left-bank) part of the city lies with­in the Dnieper low­land, which is an accu­mu­la­tive allu­vial plain com­pli­cat­ed by a series of allu­vial ter­races of dif­fer­ent ages, either super­im­posed or adjoin­ing one anoth­er. The ravine and gul­ly net­work is poor­ly devel­oped. Absolute ele­va­tions range from 100 to 140 m.

The aquifers of the city of Kyiv are nat­ur­al for­ma­tions of great impor­tance for the water sup­ply of the city and its inhab­i­tants. Kyiv is locat­ed on the Dnipro riv­er, with the most sig­nif­i­cant trib­u­taries being the Desna riv­er on the left bank and the Irpin riv­er on the right bank. With­in the city of Kyiv there are also small­er trib­u­taries, includ­ing the Lybid riv­er, the Syrets riv­er, and the Pli­akhovyi stream. The val­ley slopes of the right bank are gen­er­al­ly high and mod­er­ate­ly steep, while the flood­plains are marshy mead­ows. The rivers are low­land-type rivers fed by atmos­pher­ic pre­cip­i­ta­tion with the par­tic­i­pa­tion of ground­wa­ter. The flood peri­od usu­al­ly occurs dur­ing March–April. Sum­mer low-water con­di­tions are estab­lished in August–September, while win­ter low-water con­di­tions occur in December–January. For many cen­turies, the riv­er has sup­plied the city with water while flow­ing through its ter­ri­to­ry. How­ev­er, in addi­tion to the riv­er itself, Kyiv also pos­sess­es a large num­ber of under­ground aquifers.

Aquifers are groups of soil or rock lay­ers capa­ble of stor­ing and trans­mit­ting water. From a geo­log­i­cal per­spec­tive, the city of Kyiv is locat­ed with­in the south­west­ern flank of the Dnieper-Donets Depres­sion. The geo­log­i­cal struc­ture of the ter­ri­to­ry includes crys­talline rocks and prod­ucts of their destruc­tion, as well as Pale­o­zoic deposits (rocks of the Per­mi­an sys­tem), Meso­zoic deposits (rocks of the Tri­as­sic, Juras­sic, and Cre­ta­ceous sys­tems), Ceno­zoic deposits (rocks of the Pale­o­gene and Neo­gene sys­tems), and Qua­ter­nary deposits. Accord­ing to the geo­log­i­cal struc­ture, the ground­wa­ter of Kyiv is asso­ci­at­ed with Qua­ter­nary, Oligocene–Pliocene, Eocene, Cenomanian–Callovian, and Mid­dle Juras­sic deposits. The fig­ure presents a schemat­ic geo­log­i­cal and hydro­ge­o­log­i­cal cross-sec­tion of the ter­ri­to­ry of the city of Kyiv.

The aquifers of the city of Kyiv and its sur­round­ing areas are used to pro­vide the res­i­dents of the cap­i­tal with high-qual­i­ty drink­ing water. Through the use of spe­cial wells and pump­ing sta­tions, ground­wa­ter is extract­ed to the sur­face and under­goes purifi­ca­tion and chem­i­cal treat­ment process­es to ensure the high­est pos­si­ble water qual­i­ty for con­sump­tion. Drink­ing water must meet the require­ments of State san­i­tary norms and rules “Hygien­ic require­ments for drink­ing water intend­ed for human con­sump­tion”.

The aquifers of the city of Kyiv that occur clos­est to the sur­face are asso­ci­at­ed with Qua­ter­nary deposits. These include:

The uncon­fined aquifer of allu­vial deposits with­in the val­ley of the Dnipro riv­er, which is wide­spread through­out the left bank of the city. On the right bank, it occurs in Podil and Obolon with­in the flood­plain and the first above-flood­plain ter­race of the Dnipro riv­er, as well as in Korchuvate–Telychka and Cha­paiv­ka with­in the Dnipro flood­plain. The water-bear­ing rocks are rep­re­sent­ed main­ly by allu­vial fine- to medi­um-grained quartz sands. The waters of this aquifer every­where pos­sess a sin­gle free water sur­face. Sta­t­ic ground­wa­ter lev­els occur at depths of 1–3 m with­in the flood­plain and 5–8 m with­in the first above-flood­plain ter­race of the Dnipro riv­er. The ampli­tude of sea­son­al fluc­tu­a­tions of the sta­t­ic ground­wa­ter lev­el ranges from 0.5 to 1.5 m. Hydraulic gra­di­ents of the ground­wa­ter table with­in each area of aquifer dis­tri­b­u­tion are direct­ed toward the chan­nel of the Dnipro riv­er and range from 0.0003 to 0.001. Waters asso­ci­at­ed with the allu­vial deposits of the Dnipro riv­er are prac­ti­cal­ly unpro­tect­ed from the infil­tra­tion of pol­lu­tants from the ground sur­face.

Uncon­fined aquifers of deposits with­in the val­leys of small rivers of Kyiv are asso­ci­at­ed with the flood­plains of the Lybid riv­er, Syrets riv­er, Vita, Nyv­ka rivers, and the first above-flood­plain ter­race of the Lybid riv­er. The water-bear­ing rocks are fine-grained, very fine-grained, and mixed fine-to-very-fine sands, often interbed­ded with loams. Sta­t­ic ground­wa­ter lev­els occur at depths of 2–4 m, aver­ag­ing about 3 m. The ampli­tude of ground­wa­ter lev­el fluc­tu­a­tions ranges from 0.3 to 0.7 m. The water every­where has a free sur­face. In hydro­dy­nam­ic terms, the waters of these aquifers form ground­wa­ter flows direct­ed along riv­er chan­nels, with hydraulic gra­di­ents rang­ing from 0.002 to 0.03. The waters of these aquifers are also unpro­tect­ed from con­t­a­m­i­na­tion orig­i­nat­ing from the ground sur­face.

A con­fined-to-uncon­fined aquifer com­plex is asso­ci­at­ed with deposits of the moraine-san­dur plain and the loess plateau. Water-bear­ing rocks con­sist of sands of vary­ing grain size, sandy loams, and light loams. The waters of this aquifer com­plex gen­er­al­ly pos­sess a free sur­face. In some areas with­in the plateau, they occur beneath thick loams and loess-like loams, acquir­ing a slight local arte­sian pres­sure. The sta­t­ic ground­wa­ter lev­el varies from 4.5 to 17 m depend­ing on the local topog­ra­phy. The ampli­tude of water-lev­el fluc­tu­a­tions ranges from 0.5 to 1.5 m. Areas of dis­charge for this aquifer com­plex include the val­ley of the Dnipro Riv­er, as well as val­leys of small­er rivers and ravines. In such areas, ground­wa­ter often emerges at the sur­face in the form of springs with dis­charge rates of 0.05–0.02 dm³/s. Hydraulic gra­di­ents of the ground­wa­ter sur­face in recharge areas range from 0.001 to 0.002, increas­ing in dis­charge areas to 0.03–0.01 or more, which con­tributes to land­slide and suf­fo­s­ion process­es. The sequence of rocks over­ly­ing this aquifer com­plex fre­quent­ly includes loams and loess-like loams with thick­ness­es of 4.5–7 m, reach­ing 15–17 m with­in the loess plateau. There­fore, ground­wa­ter with­in this com­plex in cer­tain areas may be clas­si­fied as weak­ly pro­tect­ed.

On ele­vat­ed water­shed areas, the aquifers of Kyiv are rep­re­sent­ed by a con­fined-to-uncon­fined aquifer com­plex with­in the Kharkiv and Polta­va deposits. In riv­er val­leys and deeply incised ravines, this aquifer com­plex is absent. Its depth of occur­rence reach­es up to 50 m. The water-bear­ing rocks are rep­re­sent­ed main­ly by fine-grained sands with interbeds of sand­stones and clays rang­ing in thick­ness from 1 to 30 m (near the vil­lage of Novi Petrivt­si). The aquifer com­plex is over­lain by sands and red-brown clays. At the base of the hori­zon, imper­me­able marls and clays of the Kyiv for­ma­tion occur almost every­where. The aquifer com­plex with­in the Kharkiv and Polta­va deposits has a hydraulic head of up to 15 m. Well yields gen­er­al­ly do not exceed 1–2 dm³/s. Recharge of the Kharkiv–Poltava aquifer com­plex occurs in water­shed areas (where var­ie­gat­ed and red-brown clays are absent) through infil­tra­tion of atmos­pher­ic pre­cip­i­ta­tion, while dis­charge takes place in riv­er val­leys.

The aquifers of the city of Kyiv that occur below the near-sur­face hori­zons are asso­ci­at­ed with Eocene, Cre­ta­ceous, and Mid­dle Juras­sic deposits. The aquifer com­plex of the Eocene deposits is dis­trib­uted across almost the entire ter­ri­to­ry of Kyiv. The water-bear­ing stra­ta con­sist of sands of vary­ing grain sizes. On a region­al scale, the water-bear­ing rocks of the Eocene com­plex form a rel­a­tive­ly homo­ge­neous sandy sequence. The total thick­ness of this sequence varies from 10 to 60 m. Across most of its dis­tri­b­u­tion area, the water-bear­ing rocks are char­ac­ter­ized by trans­mis­siv­i­ty val­ues rang­ing from 50 to 150 m²/day. In the roof of the aquifer com­plex, deposits of the Kyiv for­ma­tion — marls and aleu­rites — occur almost every­where, giv­ing the aquifer its con­fined char­ac­ter. The thick­ness of the Kyiv marls on the right bank aver­ages 20–25 m and some­times reach­es 45 m, where­as on the left bank it gen­er­al­ly does not exceed 15–20 m, and in some places these deposits are absent alto­geth­er. The hydraulic head above the roof of the aquifer com­plex ranges from 8 to 50 m, increas­ing from west to east. Accord­ing to chem­i­cal com­po­si­tion, the ground­wa­ter of the Eocene aquifer com­plex is clas­si­fied as hydro­car­bon­ate-cal­ci­um water, typ­i­cal of zones of free water exchange. Min­er­al­iza­tion ranges from 0.1 to 0.8 g/dm³.

Arte­sian aquifers of the city of Kyiv, belong­ing to the Cenomanian–Callovian deposits com­plex, are wide­spread through­out the area. The upper part of the aquifer com­plex is rep­re­sent­ed by sands: fine- and very fine-grained in the upper sec­tion, and medi­um- to coarse-grained toward the base, in some places grav­el-bear­ing, with flint con­cre­tions, sand­stone lens­es, and inter­lay­ers of clays and silt­stones rang­ing from 5 to 20 m in thick­ness, occur­ring at depths of 80 to 160 m. The low­er part of the water-bear­ing deposits is rep­re­sent­ed by a sequence of sili­ci­fied silt­stones, aleu­ro­lites, cav­ernous lime­stones, sand­stones, and marls of the Oxfor­dian stage and the Upper Callov­ian sub­stage of the Juras­sic sys­tem. Its aver­age thick­ness is 10–20 m. Trans­mis­siv­i­ty varies with­in the range of 50–700 m²/day. Well yields range from 5 to 40 dm³/s.

These deposits are over­lain by an Upper Cre­ta­ceous marl-chalk sequence char­ac­ter­ized by low fil­tra­tion prop­er­ties. The fil­tra­tion coef­fi­cient equals 3.5×10⁻³–5.8×10⁻⁵ m/day. The water-bear­ing rocks of the Cenomanian–Callovian aquifer com­plex every­where rest upon a silt-clay sequence of the Mid­dle and Low­er Callov­ian, under­lain by Bathon­ian clays, form­ing a uni­fied region­al Juras­sic aquitard with a thick­ness of 60 m or more.

The Cenomanian–Callovian aquifer com­plex is con­fined under pres­sure. The pres­sure head above the top of the aquifer ranges from 40 to 70 m. Water lev­els in wells are estab­lished at depths from 4 to 30 m. At cer­tain water intake facil­i­ties in Kyiv, piezo­met­ric lev­els have declined to 10–15 m dur­ing the peri­od of oper­a­tion. Accord­ing to litho­log­i­cal and hydro­dy­nam­ic indi­ca­tors, the Cenomanian–Callovian aquifer com­plex is assessed as con­di­tion­al­ly pro­tect­ed from con­t­a­m­i­na­tion from the ground sur­face. The waters of the Cenomanian–Callovian aquifer com­plex are fresh, with min­er­al­iza­tion rang­ing from 0.3 to 0.53 g/dm³, and are hydro­car­bon­ate cal­ci­um-sodi­um-mag­ne­sium in com­po­si­tion. The total hard­ness of the water ranges between 2.3 and 6.0 mg-eq. The con­tent of trace com­po­nents does not exceed the max­i­mum per­mis­si­ble stan­dards. Drilling of the first water sup­ply wells for the exploita­tion of this aquifer com­plex for cen­tral­ized water sup­ply to the city of Kyiv began at the end of the 19th cen­tu­ry and con­tin­ues to the present day.

The arte­sian aquifer of the Mid­dle Juras­sic Bajo­cian deposits is wide­ly dis­trib­uted with­in the ter­ri­to­ry of the city of Kyiv. The Mid­dle Juras­sic deposits are char­ac­ter­ized by rhyth­mic alter­na­tion of sand­stones and clay deposits, due to which wells pen­e­trate from two to five aquifer lay­ers sep­a­rat­ed by weak­ly per­me­able rocks. The lat­ter are incon­sis­tent in both thick­ness and lat­er­al extent. Water-bear­ing rocks are almost every­where rep­re­sent­ed by fine-grained sands, more often medi­um-grained and coarse-grained to grav­el-bear­ing sands, alter­nat­ing with inter­lay­ers and lens­es of clay. The total thick­ness of the sandy deposits of the Bajo­cian stage varies from 1.5 to 57.0 m, increas­ing east­ward. Depend­ing on their thick­ness, the trans­mis­siv­i­ty of the rocks ranges from 120 to 500 m²/day.

At the base of the Mid­dle Juras­sic sands lies a Low­er Tri­as­sic sandy-clayey sequence. In the roof of the aquifer lies a litho­log­i­cal­ly homo­ge­neous sequence of Bathon­ian clays with a thick­ness of 55–70 m, which in turn is over­lain by silt-clay deposits of the Callov­ian stage of the Mid­dle Juras­sic with a thick­ness of up to 40–60 m. The fil­tra­tion coef­fi­cients of this sequence aver­age from 2×10⁻⁴ to 2×10⁻⁶ m/day. The depth of occur­rence of the roof of the Mid­dle Juras­sic aquifer varies from 180–200 m to 360 m. The pres­sure head ranges from 120 to 280 m. Piezo­met­ric lev­els are estab­lished at depths from 25–40 m to 130 m. In the cen­ter of the depres­sion cone (the cen­tral part of Kyiv), the depth of the piezo­met­ric lev­el reach­es 170 m. Accord­ing to litho­log­i­cal and hydro­dy­nam­ic indi­ca­tors, the Mid­dle Juras­sic aquifer is assessed as nat­u­ral­ly pro­tect­ed from con­t­a­m­i­na­tion from the ground sur­face. Nev­er­the­less, the con­struc­tion of wells drilled into this aquifer must ensure reli­able iso­la­tion of the tar­get aquifer from pos­si­ble con­t­a­m­i­na­tion orig­i­nat­ing from over­ly­ing aquifers.

Flow rates of water intake wells are 10–30 dm³/s. The waters of the hori­zon are fresh, with min­er­al­iza­tion of 0.4–0.6 g/dm3, bicar­bon­ate-chlo­ride, sodi­um-cal­ci­um and sodi­um-cal­ci­um-mag­ne­sium with a total hard­ness of up to 7.0 mg-eq. The con­tent of harm­ful micro­com­po­nents is with­in the per­mis­si­ble lim­its. The aquifer of Mid­dle Juras­sic sed­i­ments has been wide­ly used for eco­nom­ic and drink­ing water sup­ply for more than 100 years. Kyiv and adja­cent satel­lite cities.

At present, the use of Kyiv’s aquifers is con­sid­ered a ratio­nal and sus­tain­able method of pro­vid­ing drink­ing water. Local water util­i­ties and water sup­ply enter­pris­es, which are our part­ners, con­tin­u­ous­ly mon­i­tor water qual­i­ty and imple­ment nec­es­sary mea­sures to pre­serve and restore the aquifers. The ground­wa­ter hori­zons of Kyiv are an impor­tant resource that helps ensure the city’s sus­tain­able water sup­ply. They are a nat­ur­al source of drink­ing water and, at the same time, require care­ful man­age­ment and pro­tec­tion to pre­serve this vital resource for the future.