| Integrated unit of analysis | Vaal River | Schoonspruit |
| Resource unit | Vaal River main stem: from Vermaasdrift to upstream of the Schoonspruit confluence as represented by study sites 1 and 2 | Koekemoerspruit: from origin to confluence with Vaal River as represented by study sites 3, 4 and 5 |
| Water resource class | III: heavily used; overall ecological condition significantly altered from its predevelopment condition | III: heavily used; overall ecological condition significantly altered from predevelopment condition |
| Present ecological state | D: largely modified | D/E: largely modified/seriously modified |
| Recommended ecological state | D: largely modified | D: largely modified |