Sprickvatten

Sprickvatten, or fracture water, is groundwater that is stored and transmitted primarily through the fractures, cracks, and voids in bedrock rather than through pore spaces in sediments. It is a key component of groundwater in crystalline and metamorphic rocks where the rock matrix has low porosity, and where flow is governed by the geometry and connectivity of the fracture network.

Sprickvatten forms when meteoric water infiltrates the ground and enters fissures and joints in the rock. Recharge is typically localized to fracture corridors or permeable zones at the surface and may be influenced by tectonic structures. The resulting groundwater flow is often highly anisotropic and episodic, following dominant fracture pathways. Water in sprickvatten can be relatively old, with residence times ranging from years to thousands of years in some settings, and its chemical composition is strongly affected by rock-weathering processes.

Hydraulic properties of sprickvatten depend on fracture density, aperture, and connectivity rather than bulk porosity. This gives rise to variable aquifer properties: high hydraulic conductivity along fracture networks but low overall porosity. Temperature and salinity can reflect depth and geochemical interactions with the surrounding rock. Sprickvatten is a common source for wells and springs in bedrock regions and is sensitive to changes in recharge, seismic or mining activity, and groundwater withdrawal, which can alter flow paths and cause drawdown or groundwater mixing.

In hydrogeology, sprickvatten is distinguished from pore water in loose sediments and from karst or conduit groundwater by its reliance on discrete fracture systems. Its study requires fracture mapping, borehole tests, and sometimes tracer experiments to understand flow and storage in the rock mass.