The Environmental problems with the Hennops River are massive and complex. The problems have been developing over the last 50 years, as urbanisation along the river has increased. Two tributaries, the Sesmylspruit and Kaalspruit/Olifantspruit, join together to form headwaters of the Hennops River. The Hennops River and the Jukskei River join the Crocodile River which feeds into the Hartbeespoort Dam.

What happens at the headwaters of the Hennops River affects all of the water resources downstream. While the Sesmylspruit (which comes from Rietvlei Dam) is relatively clean, pollution in the Kaalspruit has become more and more of a problem with extensive urbanisation, both in terms of formal, informal and industrial townships polluting and increasing the flow in the river.

The main problems in the Kaalspruit are:

• High E.coli Counts and Conductivity
• Solid Waste (Litter)
• Erosion
• Sedimentation

E.coli counts in regions are in the hundreds of thousands, and in some places, in the millions. An acceptable level is less than 200 mg/l. The extremely high levels of E.coli in the Hennops River system pose serious threats to public health. The main contributing factors to the high E.coli counts are wastewater flowing into the river and over-flowing sewers caused by misuse and vandalism. Foam can be seen where the water is turbulent, for example at a weir. This foam is attributed to sewerage and wastewater.

• The Conductivity in regions is in the thousands. Conductivity is an indication of excess salts, which is an indication of industrial pollution.
• Litter finds its way into the stormwater system and is washed into the river when it rains.
• Erosion is caused by stormwater, illegal sand mining of river banks and damaged river systems.
• The eroded sand is deposited downstream by siltation and has completely destroyed the Centurion Lake.