The following executive summary of water security was drawn up by the Directorate Infrastructure Services of the Mossel Bay Municipality.
Mossel Bay's
municipal area receives water from the Wolwedans Dam (24Ml capacity),
Klipheuwel Dam (4.5Ml capacity), Ernest Robertson Dam (0.5Ml capacity), and the
Hartbeestkuil Dam and eight boreholes.
Untreated
water is sent to seven water treatment facilities situated strategically across
the municipal area, then to 30 stations and 55 reservoirs before reaching
37,594 customers (June 30, 2023), 38 296
to date.
The Saltwater
Desalination Plant, with a maximum capacity of 15 Ml per day, is the largest in
South Africa and guarantees that Mossel Bay remains the sole municipality able
to offer water security.
When
operational, the desalination plant feeds into the Langeberg reservoir for
distribution into the municipal water network.
RESERVIORS:
When filled
to the brim, the total volume of the town's reservoirs is 109.45 Ml. The
current volume is 92.55Ml, 83.3% of the total capacity. Mossel Bay is
authorised to sell 29,491Ml of water annually.
This results
in a mean daily supply quantity of 80.70Ml, with a daily usage of 28.26Ml.
Since the
2021/22 financial year up to and including the 2023/24 financial year, the
following new reservoirs have been added to the water supply network:
• Herbertsdale
(0.76 ML);
• Hartenbos –
Vaale Valley (7.0 Ml);
• Great Brak
River (4.0 Ml); and
•
Bartelsfontein (7.0 Ml)
MASTER PLAN:
The
municipality's current master plan for water supply is aligned with the 2030
spatial development framework (SDF).
This plan
outlines the expansion and upgrading of bulk water infrastructure to meet the
increasing demand in Mossel Bay and nearby areas, in both the medium and long
term. The ROR and the master plan for water supply are reassessed and adjusted
every five years.
WATER PROJECTS:
Mossel Bay
Municipality has completed several water sustainability infrastructure
development and upgrading projects:
- Replace waterlines (all areas): 2023/2024 + 2024/2025 = R 12 000 000. Average of R 5m per year going forward.
- Pipeline between Sonskynvallei and Brandwag: 2022/23 + 2023/24 + 2024/25 = R 16 300 000
- Upgrade waterlines to supply water to Louis Fourie Corridor Development: 2024/25 + 2025/26 + 2026/27 = R21m
- Upgrade Ernest Robertson pipelines: 2022/23 + 2023/24 + 2024/25 = R 8.5m
- Upgrade and pumpstation at Aalwyndal Reservoir: 2024/25 + 2025/26 = R2.5m
- New supply pipeline to Wolwedans Reservoir: 2024/25 + 2025/26 = R 4.5m
- Upgrade Hartenbos Heuwels booster pumpstation: 2024/25 + 2025/26 = R 2.3m
- Bartelsfontein - Upgrading of water storage capacity for Louis Fourie Corridor Development: 2025/26 = R 23m
- Refurbish and upgrading of Sandhoogte Water Treatment Works: 2025/2026 + 2026/2027=R 14m
- Refurbish and upgrading of Great Brak Water Treatment Works: 2025/2026 + 2026/2027 = R 4,6m
- Upgrade water pipeline between Great Brak Water Treatment Works and Glentana: 2024/2025 + 2025/2026 + 2026/2027 = R 5.1m
- Upgrade Friemersheim Water Treatment Works: 2023/2024 + 2024/2025 = R 4.3
- Gravity pipelines from Vaale Vallei Reservoir to surrounding residential developments: 2023/2024 + 2024/2025 = R 15.2m
- Pumpstation to supply new reservoir @ farm Vaale Vallei: 2023/2024 + 2024/2025 = R 6.9m
- Klipheuwel Dam Pumpstation (Electrical, Mechanical and Civil): 2024/2025 + 2025/2026 = R 56m
WATER PROVISION
The water services infrastructure consists of various raw water sources including the Wolwedans Dam, Klipheuwel Dam, Ernest Robertson Dam as well as 8 boreholes
with a total registered volume of 43.3 Megalitre per day. Raw water pipelines convey the untreated water to seven Water Purification Plants throughout the municipal
area. From the various water purification plants and the desalination plant (when in use), the treated water is pumped via 30 pump stations into 55 reservoirs.
The combined design capacity of the seven water treatment facilities and the desalination plant is 72.3 Ml daily.
The average daily volume of water purified during the 2023/2024 financial year was 25.04 Ml per day, and increased to 28.99Ml per day during peak periods.
A total volume of 10 329 Ml of raw water was purified at the municipal plants and a total volume of 9 137 Ml of purified water was distributed to 38 296 metered connections.
Water loss management
48 preventative maintenance tasks were carried out at pump stations/plants, and 381 water meters were replaced to minimise water losses. In addition, the following activities on the water networks were undertaken in the 2023/2024 financial year:
- New water connections = 291
- Burst water pipelines repaired = 262
- Water meter-related repair work = 1014
► Water meters older than 10 years are continuously replaced throughout the municipal area as part of the water meter replacement programme.
Replace water network lines
Water infrastructure in the Da Nova precinct was replaced since frequent burst pipes were experienced in this area using pipe cracking technology to minimise open excavations and reduce the inconvenience to the residents in the area.
This project started during the 2022/2023 financial year and will be completed during the 2024/2025 financial year.
The following was completed during the 2023/2024 financial year:
● 5 x 160mm diameter gate valves installed
● 11 x 110mm diameter gate valves installed
● 15 fire hydrants installed
● Open trench excavation and installation of pipelines:
- 175m of 160mm diameter HDPE pipelines
- 85 m of 110mm diameter HDPE pipelines
● Pipe cracking:
- Cracking 75mm AC pipes to 110 mm diameter HDPE pipes = 1351m
- Cracking 75 mm AC pipes to 160 mm diameter HDPE pipes = 186m
The total expenditure for the 2023/2024 financial year amounted to R 4 739 543 excluding VAT (CRR).
Upgrade pipeline between Hartenbos Kop Reservoir and Brandwag
This pipeline was upgraded due to the age of the existing pipeline and to cater for future increases in consumption. During the 2023/2024 financial year, a portion of the pipeline was upgraded. The remainder of the pipeline will be upgraded during the 2024/2025 financial year.
The following was completed during the 2023/2024 financial year:
● 6 200 m x 200mm diameter PVC installed
● 430 m x 200mm diameter HDPE installed
● Installation of 16 Air Valves and 7 Scour Valves
● Installation of 7 Scour Valves
The total expenditure for the 2023/2024 financial year amounted to R 6 131 943 excluding VAT (CRR).
Upgrade pipeline between Ernest Robertson Dam and Sandhoogte Water Treatment Plant
Sections of the raw water pipeline are very old and frequently require maintenance and repairs. This is a multi-year project spread over the 2023/2024 and 2024/2025 financial years. The remainder of the pipeline will be upgraded during the 2024/2025 financial year.
The following was completed during the 2023/2024 financial year:
- 1013m of trench excavation
- 628m x 315mm diameter PVC pipe installed
- 39 x Anchor and thrust blocks constructed
The total expenditure for the 2023/2024 financial year amounted to R 4 532 019 excluding VAT (Loan).
Gravity pipelines from Vaale Vallei Reservoir to surrounding residential developments
New pipelines are required to supply water to the surrounding residential developments. This is a multi-year project running over the 2023/2024 and 2024/2025 financial years.
The following projects were completed during the 2022/2023 financial year:
● 1 220 m x 400mm diameter PVC gravity pipeline
● 416 m x 315mm diameter PVC gravity pipeline
● 1 x New concrete pipe branch chamber = 45% completed
● 1 x New combined isolating and scour valve chamber on the new 400mm diameter PVC gravity pipeline = 70% completed
● 1 x New combined isolating and scour valve chamber on the new 315mm diameter PVC gravity pipeline = 56% completed
● 1 x New air valve chamber on gravity pipelines completed
The total expenditure for the 2023/2024 financial year amounted to R 6 849 949 excluding VAT (Loan).
Replacement of Fencing at Reservoirs
At the 55 reservoirs throughout the municipal area, fences regularly need to be replaced to prevent vandalism and unauthorized access.
During the 2023/2024 financial year 395 m of fencing was replaced at various reservoirs.
The total expenditure for the 2023/2024 financial year amounted to R 947 388 excluding VAT (CRR).
