Background
The Orange-Senqu River riparian States (Botswana, Lesotho, Namibia and South Africa) are committed to jointly addressing threats to the shared water resources of the Basin. This is reflected in bilateral and basin-wide agreements between the riparian states and led to the formation of the Orange-Senqu River Commission (ORASECOM) in 2000.
The ‘Orange-Senqu Strategic Action Programme’ Project supports ORASECOM in developing a basin-wide plan for the management and development of water resources, based on Integrated Water Resources Management (IWRM) principles.
The water resources of the Orange-Senqu River are heavily utilised and the system is highly regulated with 23 major dams within its Basin. It is also connected to other river systems for water import and export via six inter-basin water transfer schemes.
The project presented here addresses Environmental Flow Requirements (EFR) of the ephemeral but nevertheless significant Fish River, and the Orange-Senqu River, from its confluence with the Fish River downstream to the Orange-Senqu River mouth.
This section of the basin has not been covered in any detail by the earlier studies carried out during 2009-2010. The need for establishing the Environmental Flow Requirements is becoming increasingly` urgent due to the fact that two large dams, one in the Lower Orange (Vioolsdrift Dam) and one in the Lower Fish (Neckartal Dam), are at an advanced state of planning.
Project's on-line map
Project's on-line map presents all spatial data generated during the project. The map is hosted on the WIS geoserver system. The map provides interactive access to spatial data and attribute data associated with spatial features.
Documents
EFR Database Manual
TR10_Crerar, S, et al 2011b Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Scoping paper and terms of reference
TR19_Louw , D, et al 2011 Research Project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Inception report
TR22_Louw, D, et al 2012 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Delineation of management resource units
TR26_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Consequences of flow scenarios on ecosystem services
TR27_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: River EFR Assessment, Volume 1, Determination of Fish River EFR
TR28_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River Mouth: River EFR Assessment, Volume 2, Fish River EFR supporting information
TR29_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: River EFR Assessment, Volume 1, Determination of the lower Orange River EFR
TR30_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: River EFR Assessment, Volume 2, Lower Orange River EFR supporting information
TR31_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: River and Estuary EFR Assessment, Hydrology and river hydraulics
TR32_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Estuary and Marine EFR Assessment, Volume 1, Determination of Orange estuary EFR
TR33_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Estuary and Marine EFR Assessment, Volume 2, Orange estuary EFR supporting information
TR34_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Estuary and Marine EFR Assessment, Volume 3, assessment of the role of freshwater inflows in the coastal marine ecosy
TR35_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: EFR monitoring programme
TR36_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Database
TR37_Louw, D, et al 2013 Research Project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Summary report
TR45_Brown, C, 2013 Basin-wide Environmental Flow Regime in the Orange-Senqu River Basin
A prototype methodology for Environmental Water
Avenant, MF, 2010 Challenges in using fish communities for assessing ecological integrity of non-perennial rivers
Rossouw, L, et al 2005 Environmental water requirements in non-perennial systems
CSIR, 2011 Orange River Estuary Management Plan: Situation assessment Report submitted to Eco-Pulse
Macfarlane, DM 2013 Strategic Management Plan for the Orange River Mouth Ramsar site
Presentation_Towards_a_Management_Plan_for_Orange_River_Estuary_24_March_2011
Data
Below are all data sets generated within the project. GIS data asociated with these datasets can be accessed either through the on-line map or through the "map" link under each dataset
Ecostatus Assessment Indices
EcoStatus Level 4
Results of the EcoStatus model that integrates assessments for individual biophysical components of the system, as per Kleynhans & Louw (2007). Results based on 2012 surveys.
data files   map
Ecological Importance and Sensitivity
Results of assessment of Ecological Importance and Sensitivity according to methodology by Dr CJ Kleynhans (DWAF, 1999, updated in 2010). Results based on 2012 surveys.
data files   map
Fish Response Assessment Index
Fish Response Assessment Index (FRAI) according to Kleynhans (2007). Index determined based on 2012 surveys.
data files   map
Geomorphological Driver Assessment Index
Geomorphological Driver Assessment Index (GAI) according to Rountree and du Preez (in prep). Index determined based on 2012 surveys.
data files   map
Index of Habitat Integrity
Index of Habitat Integrity (IHI) assessed for the instream and riparian components, according to Kleynhans et al. (2009a). Index determined based on 2012 surveys.
graphs   data files   map
Macroinvertebrate Ecological Traits
Results of assessment of river health with a method developed for this study, which was based on a number of key ecological traits that were rated and weighted in terms of their importance in defining the Present Ecological State of benthic macro-invertebrates.
data files   map
Macroinvertebrate Response Assessment Index
Results of assessment of river health with a method developed for this study, which was based on a number of key ecological traits that were rated and weighted in terms of their importance in defining the Present Ecological State of benthic macro-invertebrates.
data files   map
Physico-chemical Driver Assessment Index
Physico-chemical Drivers Assessment Index (PAI) according to Kleynhans et al.(2005) and DWAF (2008b). Index values based on 2012 surveys.
data files   map
Riparian Vegetation Response Assessment Index
Riparian Vegetation Assessment Index (VEGRAI) according to Kleynhans et al. (2007). Index determined based on 2012 surveys.
data files   map
Scenario Ecostatus Assessment
EcoStatus Level 4
Results of the EcoStatus model that integrates assessments for individual biophysical components of the system, as per Kleynhans & Louw (2007). Results based on 2012 surveys.
data files   map
Fish Response Assessment Index
Fish Response Assessment Index (FRAI) according to Kleynhans (2007). Index determined based on 2012 surveys.
data files   map
Geomorphological Driver Assessment Index
Geomorphological Driver Assessment Index (GAI) according to Rountree and du Preez (in prep). Index determined based on 2012 surveys.
data files   map
Macroinvertebrate Ecological Traits
Results of assessment of river health with a method developed for this study, which was based on a number of key ecological traits that were rated and weighted in terms of their importance in defining the Present Ecological State of benthic macro-invertebrates.
data files   map
Macroinvertebrate Response Assessment Index
Results of assessment of river health with a method developed for this study, which was based on a number of key ecological traits that were rated and weighted in terms of their importance in defining the Present Ecological State of benthic macro-invertebrates.
data files   map
Physico-chemical Driver Assessment Index
Physico-chemical Drivers Assessment Index (PAI) according to Kleynhans et al.(2005) and DWAF (2008b). Index values based on 2012 surveys.
data files   map
Riparian Vegetation Response Assessment Index
Riparian Vegetation Assessment Index (VEGRAI) according to Kleynhans et al. (2007). Index determined based on 2012 surveys.
data files   map
Riverine Fauna
Results of assessment of riverine fauna conditions under the flow scenarios based on a process developed especially for this project. The main components of this process that are considered comprise the expected riverine fauna species to the area, their probability of occurrence and quality of habitat present. Assessment done on the basis of survey performed in June 2012.
data files   map
Raw Ecological Data
Diatoms
Diatom abundances at projects sites surveyed in 2012, and at other sites in the basin surveyed between 2008 and 2012.
data files   map
Estuary Birds
Bird species abundances surveyed in November 2012 at 4 locations within the Orange River Estuary
data files   map
Estuary Fish
Fish catches in the Orange River Estuary.
data files   map
Estuary Macroinvertebrates
Macroinvertebrate counts at a number of sites in the Orange River Estuary in Sept 2014, but also in 2004 and 2005
data files   map
Estuary Macrophytes
Macrophytes present in the Orange River Estuary.
data files   map
Estuary Microalgae
Microalgae counts at a number of locations within the Orange River Estuary
data files   map
Fish
Fish counts at projects sites surveyed in 2012.
data files   map
Macroinvertebrates
Macroinvertebrate counts at projects sites surveyed in 2012, and between 2008 and 2012.
data files   map
Hydrological Data
HEC-RAS hydrodynamic model
Model configuration and results of modelling of Fish River hydrodynamics in the Neckertal-Ais-Ais reach. Data stored in the native HEC-RAS format.
data files   map
Pitman model parameters
These are parameters of Pitman model obtained during model calibration.
data files   map
WRYM Integrated Vaal River System Model
Model configuration and results of modelling of Orange River basin with water management model WRPM. Data stored in the native WRPM format.
data files   map
WReMP Fish River Water Management Model
Model configuration and results of modelling of Fish River with water management model WReMP. Data stored in the native WReMP format.
data files   map
monthly rainfall input to model
These are monthly rainfall amounts for each of the subcatchments simulated in the Pitman model. The data were derived from observations at individual stations, which were interpolated and converted to subcatchment-area monthly totals. Data cover the period of Oct 1930-Sep 1995.
graphs   data files   map
present day disaggregated daily flows
These are river discharges at a number of 'nodes', or outlets of
subcatchments, simulated with a calibrated Pitman hydrological model for
current conditions in the basin. The simulations cover the period of Oct 1930-Sep
1995. Sata presented here are disaggregated using statistical methods from monthly output of the Pitman model.
graphs   data files   map
present day monthly flows
These are river discharges at a number of 'nodes', or outlets of
subcatchments, simulated with a calibrated Pitman hydrological model for
current conditions. Current conditions - cover the period of Oct 1930-Sep
1995. Pitman model is run at monthly time step, and data presented here are
monthly. Files contain either 'incremental' flow, i.e. flow generated within subcatchment corresponding to a node, or total flow, i.e. flow generated upstream from a node, or, in case of dams, spill flow.
graphs   data files   map
scenario disaggregated daily flows
These are river discharges at a number of 'nodes', or outlets of
subcatchments, simulated with a calibrated Pitman hydrological model for
prescribed water management and development scenarios. The simulations cover the span of 66 years. Data presented here are disaggregated using statistical methods from monthly output of the Pitman model.
graphs   data files   map
scenario monthly flows
These are river discharges at a number of 'nodes', or outlets of
subcatchments, simulated with a calibrated Pitman hydrological model for
prescribed water management and development scenarios. The simulations cover the span of 66 years. Data presented here are monthly.
graphs   data files   map
stage-discharge relationship
These are results of measurements topographic transect, water level and flow discharge at cross-sections at core sites.
data files   map
Water Quality and Sediment Data
Estuary Sediment
Results of granulometric analyses of sediment samples from a number of locations within the Orange River Estuary. Locations of sampling sites not georeferenced.
data files   map
Estuary Water Quality
Results of water quality measurements from a number of locations within the Orange River Estuary.
data files   map
Metadata
Shapefiles metadata
Shape files presented in this website contain attribute tables that store refrences to data files pertaining to each of the georaphical feagures. The shapefile metatdata contains description of column names of these attribute tables. It is a Comma Separated Value file that can be read with a text editor or opened in MS Excel.
data files   
Maps
These are project maps included in the project reports. All are in jpg format. GIS data underlying them are shown elsewhere in this page
basemap
Basemap of the project. Shows location of the study site, subdivision of the rivers into Management Resource Units, gauges etc.
Low resolution   High resolution
diatom
Map shows location of diatom sampling sites
Low resolution   High resolution
nodes
Location of outlets of subcatchments represented in the Pitman hydrological model run for the project
Low resolution   High resolution
raingauges
Location of rain gauges used in the study
Low resolution   High resolution
waterquality
Map shows location of water quality monitoring and sammpling sites
Low resolution   High resolution