Tapping of Karst Groundwater

Abstract

The tapping of karstic groundwater flow as an “invisible” resource can be done in two ways: directly at springs’ discharge points and within the aquifer catchment by artificial intakes such as wells, galleries, or other similar structures. Although many spring intakes are not engineering masterpieces and were constructed by local semiskilled inhabitants, to ensure technically proper and environmentally friendly tapping of springwater, many steps in design, construction work, and utilization as well as in springwater protection from pollution should be taken. These steps are further discussed and optimal order in their implementation proposed. The design of the tapping structure of springs depends mostly on the discharge mechanism, and through several examples, optimal solutions for tapping ascending or gravity flows are shown. How to calculate spring box volume or why and where to locate additional sediment boxes within a tapping chamber are also presented. The list of activities and general specification of construction works at the spring site may be used not only for training purposes but also as a reminder in engineering practice. The issue of drilling the wells was discussed from several points of view: feasibility, determination of drilling site, and well design. The last includes selection and optimization of drilling method, the depth of the well, drilling diameter, casing/grouting, well development, and pumping. Six drilling technologies are briefly explained, and their advantages and disadvantages for use in karstic rocks are also discussed. Additionally, as an important fact for the well’s productivity, emphasis is given to the selection of the types of screens for wells, including open-hole option. Along with the explained and proposed procedures of development and pumping of the well, some important technical questions such as how to optimize yield, select, and install a pump and protect the well head are also emphasized.