Calvinia receives seasonally variable water from either surface water source (Karee Dam), or from groundwater sources. During early winter, the raw water is sediment laden and highly turbid, but later in the season algal blooms are predominant with related taste and odour problems. To counter these issues, the new plant was planned to provide the following new facilities:

• 4 x Rapid Gravity Filters with combined air-water scour capability
• The existing clarifiers were converted to conical Dortmund type clarifiers
• Dissolved Air Flotation facility for removal of algae
• New Chemical Dosing facility to allow the use of multiple coagulants
• New Chlorine Dosing Facility for disinfection with Calcium Hypochlorite
• New Plant Room housing the Clear Water Pumps, Backwash Pumps, Air Scour Blowers, DAF Recycle Pumps, Air Compressors and the Saturation Vessel
• New electrical switchgear and fully automated operation and control system

Construction of the Calvinia Water Treatment Plant Upgrade commenced in March 2020, and was completed in May 2021.