Water is essential for the survival of plants and animals, both of which have developed mechanism for dealing with their specific water requirements according to the demands of their native environments (Meyer and Casey 2002). Water related stress occurs when an organism is exposed to either a deficiency or an overabundance of water relative to its ecological requirements. The placing of watering points and licks is crucial to ensure an even utilisation of the veld and to limit soil erosion due to footpaths to and from the water points. The correct number and placement of water point is important to control animal movement and to avoid over-utilisation and veld deterioration. Surface erosion will reduce water infiltration and excessive water run-off will lead to further erosion. Soil types susceptible to accelerate erosion such as duplex soils should be avoided. The optimum utilisation of the veld on wildlife ranches is dependent on adequate and well distributed water points. The provisions of water of good quality and the protection of water resources for long-term sustainability are becoming critical management issues the type of water hole to be is determined by a variety of factors such as rainfall, location, topography, soil type, types of animal to be kept, grazing management and finances. The provision of water of good quality is often underrated in game ranch management. According to Meyer and Casey (2002) water of poor quality has caused destruction effect. The following broad guidelines usually apply for an ideal waterhole to a game ranch:
Requirements for an ideal waterhole
When constructing and locating new waterhole, certain criteria concerning the animals and their behaviour as well as the environment need to taken into consideration, the following requirements apply (Du Toit and Van Rooyen 2002):
- Sufficient water should be economically exploitable.
- The design should satisfy the drinking preferences of different animal species.
- The water supply should be controllable so that it can be opened or closed to encourage animals to utilize other areas of the ranch with an alternative water supply.
- The design should limit losses if competition for water occurs between different animal species.
- The distance between adjacent waterholes should be considered so as to limit over- or under grazing.
- The water supply should be permanent and reliable, especially during times of drought.
- There should be sufficient shade in the area around the waterhole where those animals that require it can rest after drinking.
- The waterhole should be constructed in such a manner that it allows maximum game-viewing, coupled with minimum disturbance to animal movements by tourists.
- Waterholes should not be placed on watersheds or on highly erodible soils because this encourages soil erosion.
- Waterholes should be designed in such a way that they provide minimum cover for predators.
- The water quality should be suitable.
- The waterhole should look as natural as possible.
To determine whether a water resource is fit for use by wildlife, a risk management should be done. For this, information regarding the animal species present, the environment involved, nutrition and water chemistry is required. Once formulated, the assessment should identify any problems associated with the water resource. Even a standard water analysis can provide a rough guideline of potential dangers. Problems associated with water taste are usually easy to observe, toxicological problems may be unnoticed, or they may be attributed to other factors such as poor nutrition or internal parasites. Some of these toxicological effects lead to the reduction in reproductive efficiency, fertility, viability of offspring, growth rate and resistance to disease. Clinical symptoms for specific toxicants may also be noticed (Meyers and Casey 2002).
The type of waterholes
It is important to evaluate the situation on the game ranch and then plan thoroughly before constructing a waterhole. The advantages and disadvantages of each type of waterhole should already have been defined and taken into consideration during the planning phase. A game ranch containing a variety of animals, a combination of waterhole designs may therefore be ultimate solution. Main types of waterhole to be considered on the game ranch are the following (Du Toit and Van Rooyen 2002):
Artificial earth dams
An artificial earth dam usually consists of a hollow that is scraped or scoured in the ground, and is then allowed to fill with run-off water from the veld or with water from a nearby reservoir or borehole. This type of waterhole is aesthetically pleasing, is easily controlled, is utilised by a large variety of plain animals and seldom leads to soil erosion when the dam is correctly placed and designed. However, it requires the maintenance of borehole equipment that should be expected regularly for problems. When placed in easily crumbled soil, trampling by animals will make the water excessively muddy. Sandy soils located away from cleared areas are ideal for earth dams. Dams on clay soils lose less water but there is an increased danger of erosion and veld trampling because of the sweet grazing found around the area (Du Toit and Van Rooyen 2002).
A trough with a reservoir
A concrete or fiberglass trough linked to a resevoir is permanent and easily controllable for veld management purposes. It can easily be cleaned and thus facilitates disease control. Because of the relatively small area, water loss by evaporation is low. Some animals, however, prefer a more natural type of waterhole. Troughs are also relatively small and may lead to injuries amongst aggressive animals such as gemsbok and Burchell’s zebra. Young animals may drown when large herds crowd around a trough. Animals such as the giraffe may experience difficulty in drinking from a trough when the approach is coated with smooth cement, because they may slip when they bend down to drink. Trouhs also need reservoirs to feed them, which means that the borehole equipment has to be installed and maintained (Du Toit and Van Rooyen 2002).
Placement of waterholes
When correctly placed waterholes seldom lead to soil erosion. Dams on soil with high percentage of clay content loose less water, but trampling and erosion causes problems in such areas. With the exception of storage dams, all waterholes should be constructed on level areas. The maximum slope allowed on the site is 5°. When this gradient is exceeded, erosion and trampling can occur. When possible, no waterhole should be placed in sweetveld areas, particularly on or near brackish areas where the naturally sparse grass cover increases the danger of trampling and erosion (Du Toit and Van Rooyen 2002). The construction distance between watering points vary according to the size and type game species kept (Trollope 1990). Waterholes should preferably be constructed at least 100 m away and upwind from such such places. Waterholes that are too far apart may result in gaps of unutilised veld, whereas waterholes that are too close to each other may cause severe over-utilisation and trampling of the veld. The waterholes should also be spaced to limit competition between animals around the waterhole. The nature of the veld and animal species involved will serve as guidelines for the correct placement of waterholes (Du Toit and Van Rooyen 2002). Where the provision of drinking water is difficult it is possible, within reason, to select animal types which can tolerate conditions in which water is poorly distributed or where the overall supply of water is restricted (Tainton 1999). When an observation point is constructed at a waterhole, a screened walkway of at least 100 m from the parking area to the observation point is needed so as to limit disturbance by the visitors. Troughs have some advantages over dams and pans. Because of the smaller surface area, less water evaporates and ia lost troughs are cleaned much easier than dams and pans, facilitating disease control. When too many animals drink from same trough, a second through can may be constructed 40 to 100 meters away.
Recommendations for Highlands Wilderness
The type of water points affects its use by various animals. The number and location of waterholes may control animal population. Clustered water points are best located within a radius of 500 m, in order to split up large herds. Most conflicts between different species and between members of the same species occur when waterholes, water supplies and drinking space is limited. The current water supply on Highlands Wilderness Game Ranch is insufficient for the animals stocked. There are only two permanent water points (Figure 19) which are approximately 2.5 km far apart. Types of waterholes on the ranch are artificial earth dams (Figure 20). Water point on the south-western side (Figure 20) is not reliable source for water supply especially during dry season. The waterholes require reliable maintenance of borehole equipment that should be inspected regularly for problems especially in low rainfall season. Highlands Wilderness Game Ranch is characterised by vast number of hills, and level areas to erect new water points are very limited. It would be advised to provide another permanent artificial earth dam (Figure 19) on the north-eastern level area side of the ranch, which is next to old gate, neighbouring Ochna pulchra Game Ranch. The waterhole will provide sufficient water for animals occupying the mountain habitat. Natural water source streams through the ranch are all non-perennial and are not sufficient for animals.