Izrada injekcijskih zavjesa u kršu relativno je čest graditeljski zahvat vezan s izgradnjom brana i akumulacija u kršu. Njena osnovna uloga je smanjivanje gubitaka vode iz akumulacije kroz krški masiv koji se nalazi ispod brane, sprječavanje mehaničkog ispiranje sedimenata ispune pukotina i krških kanala te korozijsko proširivanje pukotina. U radu je analiziran slučaj injekcijske zavjese ispod brane Đale na rijeci Cetini. Dužina ove zavjese iznosi 3966 m, a njena najveća dubina seže 120 m ispod dna brane. U članku je izvršena analiza satnih vrijednosti vodostaja i temperatura podzemnih voda mjerenih u šest dubokih piezometara (označenih brojevima 1, 2, 3, 4, 5 i 6) u razdoblju od 1. rujna 2008. u 02 sata do 31. prosinca 2009. u 23 sata (ukupno 11.687 sati). Za ostala tri piezometra (označenih velikim slovima A, B i C) raspolagalo se s diskontinuiranim mjerenjima razina i temperature podzemne vode. Ustanovljeno je da je izgradnja injekcijske zavjese uzrokovala nagle i potencijalno opasne lokalne promjene režima podzemnih voda. Detaljnije je izučeno ponašanje razina podzemne vode u bliskim parovima piezometara od kojih se jedan nalazi u područja između akumulacije i injekcijske zavjese, a drugi izvan. Izgradnjom injekcijske zavjese potpuno je izmijenjen lokalni režim podzemnih voda. Posebno se upozorava na činjenicu na to da se hidrostatski pritisak na zavjesu brzo mijenja te da doseže do 40 m, što može biti opasno za njenu dugotrajnu stabilnost..; The construction of grout curtains in the karst is a relatively frequent building procedure in the construction of dams and reservoirs in the karst. Its primary role is to reduce water losses from the reservoir through the karst massif located below the dam and prevent mechanical flushing of sediment from filled joints and karst canals and corrosive widening of the joints. The paper analyzes the case of the grout curtain below the Đale dam on the Cetina river. The length of the curtain is 3966 m, with the maximum depth of up to 120 m below the dam bottom. The paper analyzes hourly values of ground water levels and temperatures measured in six deep piezometers (marked with numbers 1, 2, 3, 4, 5 and 6) in the period from September 1, 2008 at 2 a.m. until December 31, 2009 at 11 p.m. (total of 11,687 sati). For the remaining three piezometers (marked with letters A, B and C), occasional measurements of ground water levels and temperatures were available. It was determined that the grout curtain construction caused sudden and potentially dangerous local changes in the ground water regime. A more detailed study was carried out of ground water behaviour in the close piezometer pairs, of which one was located in the area between the reservoir and the grout curtain and the other outside of it. The construction of the grout curtain completely changed the local ground water regime. It is of special note that the hydrostatic pressure quickly changes and reaches up to 40 m, which can be dangerous for its long-term stability.