A brief history

The history of Warmwaterberg Spa as an operating hot spring resort commenced in 1887 with the erection of the first public facility in the form of the Historic Bath Houses which still stand and are used as accommodation to this day. They were built by the Le Grange family who purchased the farming property in 1885. In this regard it is important to note that the main business of the time was farming and the resort was run as an adjunct.

Before this time the travellers of old also made use of the springs but were forced to make use of the protection of bushes, tents or those that had, their ox-wagons. It would appear that William Paterson was the first to make mention of the springs in June 1778 in his writings and shortly thereafter in 1780 it appeared on maps for the first time. To this day it is marked as “radioactive springs” on some maps. Don’t worry – the radioactivity is hardly measurable, and in no way injurious to your health. To the contrary – the very high levels of Iron and (relatively) Lithium are very healthy.

Motivated by the commercial success of the new Hotel completed in 1902 at the hot springs at Caledon and funded by their new-found wealth as a result of the ostrich boom, the family decided to expand the facilities offered by erecting a sanatorium 1906. The word “Sanatorium” was never used in the context of mental illness, but rather its broader Victorian meaning as a place of healing or wellness. Thus did Warmwaterberg Spa become the second fully-fledged Spa in South Africa.

Today the Spa and surrounding farmland is owned by the 6th-generation descendants of the founder. The business must therefore be one of the oldest operating Spa establishments in South Africa as it celebrated its 125th birthday in 2012.

Warmwaterberg Geology

Two main geological Groups are identified in the study area: The Ceres Subgroup of the Bokkeveld Group, and the Nardouw Subgroup of the Table Mountain Group. The mainly sandstone Table Mountain Group unconformably overlies the pre-Cape rocks and is conformably overlain by the predominately shale layers of the Bokkeveld Group (Meyer, 1999).

The Table Mountain Group (TMG) consists of three main units (with the approximate deposition thickness): The basal Peninsula Formation (1 500 m), the Cedarberg Formation (50 m) and the topmost Nardouw Subgroup (900 m). The Nardouw Subgroup consists of the Goudini Formation (300 m), Skurweberg Formation (400 m) and Rietvlei Formation (200 m) west of 21° 30’ E.

According to Meyer (1999) the following are the more important geological and groundwater characteristics of the TMG.

A network of joints and fractures control the infiltration, recharge, storage and flow of groundwater in the competent sandstone units. Fracturing may extend down to several hundred metres with deep groundwater circulation common.
Recharge of 15% of rainfall is estimated for the highly fractured mountain ranges of sandstone.
Springs are common with 3 kinds of springs occurring:
- Fault and major structure controlled, generally deep circulation springs issuing often large constant supplies. The Calitzdorp hot spring with a constant yield of 11.6 L/s is an example.
- Lithologically controlled, relatively shallow circulating springs.
- Springs from numerous small fractures and joints.
Strong borehole yields can be expected in the TMG, with poor yields generally being attributed to poor borehole position or too shallow drilling.
The groundwater quality of the TMG, expressed in term of electrical conductivity or salinity, is generally between 10 and 100 mS/m.

The Bokkeveld Group is comprised of two Subgroups, namely the basal Ceres Subgroup and the topmost Traka/Bidouw Subgroup. The Ceres Subgroup consists of 3 shale units, with estimated deposition thickness in parenthesis: The Gydro Formation (600 m), Voorstehoek Formation (300 m) and the Tra-tra Formation (350 m) and three sandstone units, the Gamka Formation (200 m), Hex River Formation (70 m) and Boplaas Formation (100 m) to the north of the Langeberg Mountain ranges (Meyer, 1999).

Borehole yields and the quality of the groundwater varies greatly depending on the Bokkeveld Group lithology. Yields of more than 5 L/s are not uncommon in the sandstone-richer Ceres Subgroup (Meyer, 1999). Electrical conductivity of groundwater within the Ceres Subgroup ranges from 30 to 400 mS/m, with Na, Mg, Cl and SO4 repeatedly exceeding recommended limits (Meyer, 1999) for these elements.

Structural Geology

The Cape Fold Belt is generally east-west striking within the Klein Karoo area and consists predominantly of sandstone and shale rocks that underwent intense pressure from the south. The structural geology relevant to the study site can be summarised from Meyer (1999) as follows:

• Northward orientated anticlines in the competent Table Mountain Group resulted from intense folding (forming the backbone of the mountain ranges).
• Anticlines and synclines of parasitic folds exist in the less competent Bokkeveld Group (Toerien, 1979 in Meyer, 1999).
• Overfolding and thrusts are common structural features, especially along the northern boundaries of the mountain ranges (Toerien, 1979 in Meyer, 1999).
• The degree of folding decreases northwards (Theron et al, 1991 in Meyer, 1999).
• The presence of reverse and normal faults (compression and extension forces) and numerous post-Cape (younger) strike faults with considerable displacements (Toerien, 1979, in Meyer, 1999)
• Brittle failure is evident in the competent sandstone units of the Table Mountain Group, but to a lesser degree in the sandstone units of the Bokkeveld Group.

Very little has been published in scientific journals about the Warmwaterberg hot spring specifically. The Warmwaterberg hot spring is mentioned briefly in relation with the deep geothermal springs in Montagu, Caledon, etc.