At Umvoto protecting biological diversity is a core principle that informs all of our work. As groundwater and surface water are integral components of the hydrosphere, the use of groundwater can potentially have impacts on the flora and fauna in groundwater-dependent ecosystems (GDEs) such as spring/seep-related wetlands. Once Umvoto identifies and delineates a GDE, a range of monitoring methods are employed across relevant projects. In honour of the 2023 International Day for Biological Diversity, of which this year’s theme is “From Agreement to Action: Build Back Biodiversity”, Umvoto is proud to share six ways GDEs can be monitored, actively contributing to the protection and “building back” of biodiversity (especially within the Cape Floristic Region biodiversity hotspot).
Six methods of monitoring GDEs
1. Water levels
In the Cape Flats Aquifer Management Scheme (CFAMS), Umvoto closely monitors shallow water levels in piezometers that have been installed in the heart of wetlands that support a variety of species, including insects, frogs, and even flamingos. The long-term objective of the CFAMS is to enhance groundwater quality of the aquifer and revive urban ecosystems through managed aquifer recharge (MAR). The water levels in these wetlands serve as a baseline understanding of the interaction between groundwater and surface water before the MAR initiative is implemented.
Groundwater levels of the Table Mountain Group (TMG) aquifers are also monitored extensively within Steenbras Wellfield, especially adjacent to identified GDEs (in association with soil moisture) to ensure any potential impacts of bulk groundwater abstraction are limited.
2. Stilling wells
Umvoto has installed stilling wells in the upper reaches of the Steenbras Dams catchment’s crystal-clear streams, which originate from the elevated Kogelberg Mountains. The TMG aquifers overflow and discharge as springs/seeps, forming the source of these streams and pristine aquatic environments that support a range of flora and fauna, including critically endangered fish species. By monitoring the stream’s flow using the stilling well, along with nearby weather data, the amount of groundwater contribution to the stream can be determined, known as the baseflow. If the baseflow decreases, and it can be shown to be related to groundwater abstraction, then wellfield abstraction can be reduced to safeguard these biodiversity hotspots and maintain high-quality aquatic habitats.
3. Soil moisture
Mountain springs and seeps are home to numerous critical fynbos species that form the foundation of thriving GDEs. Through strategically placed soil moisture probes installed at varying depths, data can be gathered on the saturation levels and hence habitat quality in these areas. As sensitive plant and animal species rely on specific soil moisture levels to survive and thrive, this information is vital. Strategically installed automatic weather stations record additional critical data such as rainfall, wind direction/speed, humidity and evapotranspiration, to provide a comprehensive understanding of these GDEs. This enables GDEs to be safeguarded in their ability to provide essential ecological services.
4. Plant counts
In the Fernkloof Nature Reserve, located upgradient of various TMG wellfields in Hermanus, Umvoto undertakes headcounts of Berzelia plants that grow in GDEs related to spring discharge from the Peninsula Aquifer of the TMG. Berzelia lanuginose, also known as “Kolkos” or “Kuikentjiebos”, is an endemic plant of the Cape Floral Kingdom and thrives in permanently wet areas. This species serves as an excellent indicator of wetland health, size, and overall biodiversity. Moreover, it is a valuable source of food for honeybees.
5. Invertebrate counts
In the streams surrounding the Steenbras Dams, a variety of invertebrates, including insects, crustaceans, molluscs, and worms, are essential components of the food web and play critical roles in nutrient cycles and decomposition processes. Monitoring the populations of these invertebrates offers valuable insights into changing water quality, potential contamination, and stream flow. Species like the rare Blephariceridae are highly sensitive to environmental changes, making them effective early warning indicators for overall habitat health. These ecosystems are vital components of the Cape Floristic Regional and require robust protection.
6. Fixed photo points
Fixed photo points (FPPs) demonstrate the importance of observation. Every time a GDE is visited for monitoring, a photo is taken from the same location and orientation, enabling subtle changes to be tracked over time. Wetlands are dynamic systems, with constantly changing water levels, water quality, vegetation, and geomorphology that impact the biodiversity they support. An added bonus is a database full of beautiful photos.
Biodiversity monitoring and protection
Umvoto monitors an array of GDEs, from the pristine springs and mountain streams of the Steenbras Dams catchment to the highly disturbed and impacted Cape Flats wetlands. As custodians of Earth we all must do our part to preserve our natural environment and the ecosystems that support life around us. Even the most impacted ecosystems are worth restoring and protecting. In our effort to support the theme of the 2023 International Day for Biodiversity, let us all take action to help monitor, protect and “build back” biodiversity.