Overstrand Local Municipality Groundwater Management

Hermanus

Umvoto Africa was appointed by Overstrand Local Municipality (LM) in 2001 to proceed with a groundwater investigation and exploration to augment the water supply to the growing town of Hermanus. After completing the drilling and testing programme at Gateway Wellfield and the surrounding area in the mid-2000s, with groundwater abstraction being initiated from the fractured Peninsula Aquifer of the Table Mountain Group (TMG) at the same time, a monitoring programme was developed and implemented using new monitoring boreholes and existing surface/groundwater-related infrastructure. Further to the successful establishment and operation of the Gateway Wellfield for several years, Umvoto Africa assisted the Overstrand LM to monitor and operate the Camphill and Volmoed Wellfields in the Hemel en Aarde Valley. Umvoto Africa continues to offer their services as groundwater specialists to the municipality through on-going wellfield operation and management support, groundwater and ecological monitoring as well as support with legislative compliance and wellfield expansion. 

Umvoto Africa has been monitoring the water supply of the greater Hermanus region for approximately eight years. De Bos Dam (surface water supply) supplies on average 70% of the water demand to the town, whereas the other 30% is supplied from Peninsula Aquifer (TMG) groundwater (abstracted from Gateway, Camphill and Volmoed Wellfields). This groundwater supply ensured the region was water secure through the 2009-2011 Southern Cape drought and the 2015-2019 Western Cape drought. Both Gateway Wellfield and the combined Camphill/Volmoed Wellfields have the potential to supply 1.6 million cubic metres per year to the greater Hermanus region each (so a combined total groundwater supply of 3.2 million cubic metres per year, or almost 9 million litres per day). With planned expansion of all three wellfields currently underway (where the high yielding GWP16 and GWP17 boreholes are currently being commissioned) and planned for completion towards the end of 2021, groundwater will supply up to ~65-70% of the greater Hermanus region’s predicted 2025 demand of ~4.5-5 million cubic metres per annum.

Hermanus Blow Yield

Stanford

Umvoto Africa has been contracted by the Overstrand LM since 2007 as the Professional Service Provider to undertake the water resource development and management of the Stanford Aquifer (which is a primary aquifer comprised of dune, fluvial and shallow marine sediments of the Bredasdorp Group). The main aim of the project is to secure groundwater as a long-term option for municipal water supply of Stanford and manage it sustainably on behalf of Overstrand LM. The Stanford Aquifer is at present (and likely to remain in the future) the sole source of supply of potable water to the town (with a water use licence abstraction limit of 1.6 million cubic metres per annum), as well as for farmers and other users in the area. Groundwater from the Stanford Aquifer is pumped from two sources, namely “The Eye” (an existing spring, which Umvoto Africa upgraded the abstraction infrastructure of) and the Kouevlakte Wellfield (developed by Umvoto Africa), to a storage reservoir, from which it is fed to the municipal water reticulation system.

Stanford Leiwater Eye

Baardskeerdersbos

Umvoto Africa has assisted the Overstrand LM with the operation and management of the Baardskeerdersbos Wellfield since 2018 and is responsible for undertaking groundwater monitoring of wellfield operations and surrounding monitoring sites within the Peninsula Aquifer.

Treated Wastewater Irrigation Monitoring

Umvoto Africa also monitors soil and groundwater for Overstrand LM in areas adjacent to sports fields irrigated with treated wastewater in Hermanus and Gansbaai, in order to ensure the municipality complies with its Section 21(e) water use licence conditions and that no contamination occurs.