|Developing an elementary tool for ecological reserve monitoring in South Africa’s Freshwater Ecosystem Priority Areas (FEPAs): A pilot study in the Koue Bokkeveld
|Expanded Title:||Extensive research and development has gone into methodologies aimed at determining the Ecological Reserve in South Africa, i.e. into quantifying the volumes, timing and frequency of flows required to support ecosystem processes in local rivers. Considerably less attention has been accorded its operationalisation; with some managers alleging that
Reserve determination methodologies have been developed in a vacuum without any serious consideration for their practicability. This study was undertaken in response to
the need to develop simple tools to monitor the Reserve that can be broadly applied in rural catchments with limited water resource management capacity and monitoring, a decentralised
water storage and transfer infrastructure, but which have a high conservation and biodiversity value, i.e. Freshwater Ecosystem Priority Areas (FEPAs). One of the fundamental premises of this study is the notion that operationalisation of the Reserve in
river catchments stands a better chance of succeeding if more knowledge and control is placed in the hands of Water User Associations (WUAs) (representing both established
commercial and emerging farming sectors) since they play a critical day-to-day role in the management of local water resources. By providing a set of easily interpretable tools and
the basic skills required to manage their water resources more efficiently, this project aims to play a role in their institutional development through providing a significant link at the science-management interface.
Aims and objectives
The primary aims of the FEPAs and Flows study are therefore to:
• establish rated cross-sections at flow monitoring sites for FEPA-listed rivers and their support areas at selected nodes in the Koue Bokkeveld sub-catchment;
• assimilate the latest data from the WRCS hydrology and reconcile this with Olifants and Doring Rivers;
• gather information on present day water use collected by field personnel assigned to the Cape Critical Rivers (CCR) Project;
• use the above information to provide specialist ecological, hydraulic and hydrological support to the CCR Project; and
• investigate elementary, cost-effective monitoring tools and protocols for monitoring the Reserve in catchments of high ecological importance that can be broadly applied by non-technical personnel within CMAs, WUAs and conservation
extension officers throughout South Africa.
General Approach and methodology
• 1) Hydrology – Modelled hydrological data used in the recently completed Water Resource Classification Study for the Olifants-Doring catchment was derived for the period 1920 to 2004 using the most recent calibrated information wherever possible. The Natural and Present Day hydrology from the classification study
was used for validating the WRCS data, together with updated information from existing DWS flow monitoring gauges and those which were installed during the course of this study. As part of the ‘Methodological Approaches to Assessing Eco-Hydrological Responses to Climate Change in South Africa’, hydrology has
been modelled at the quinary catchment scale for the country. The team investigated the usefulness of this data for Reserve monitoring.
• Hydraulics – Accepted and locally developed methodologies were used to derive a rating curve relating river stage to discharge across a stable transect that exhibits uniform flow on the Twee and Riet Rivers. A rating curve was then fitted through the observed and modelled points to allow the conversion of discharge to depth and to other variables including average velocity and wetted perimeter. The hydraulic analysis produced the following information: (1) a time series of stage based on the time series of flow, (2) a cross-section plot showing the observed
and modelled flows and stages, (3) a plot showing the rating curve, the rating curve equations, and (4) lookup tables of various hydraulic variables versus flow including maximum depth, average depth, average velocity and others.
• Monitoring indicators – The project team developed a set of monitoring indicators to aid with the monitoring of the Reserve in the Koue Bokkeveld. A relatively inexpensive, as well as easily communicated and interpreted environmental flow monitoring tool was developed from these indicators. Opportunities for engaging the Koue Bokkeveld WUA in applying the monitoring tools was investigated through the Cape Critical Rivers (CCR) Project.
• Stakeholder participation and engagement – engagement with the Koue Bokkeveld WUA, DWS and CapeNature was central to the intended outcomes of this study and the CCR Project.
|Document Type:||Research Report
|Document Subjects:||Ecosystem - Biodiversity protection, Ecosystem - Invertebrates
|Document File Type:||pdf
|Research Report Type:||Standard
|WRC Report No:||2340/1/16
|Authors:||Paxton B; Dobinson L; Kleynhans M; Howard G
|Document Size:||2 839 KB