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Llwyn-onn Reservoir
Reservoir
Cool today
Editor's Notes
Llwyn-onn Reservoir is the largest and southernmost of the three reservoirs in the Taf Fawr valley in South Wales. Cardiff Corporation Waterworks obtained an act of Parliament in 1884 to authorise construction of the reservoirs, to increase the water supply for Cardiff, but construction of Llwyn-onn Reservoir did not start until 1911 and was completed in the 1920s.
The reservoir, which has been owned and managed by Welsh Water and its predecessor organisation, the Welsh Water Authority, since 1973, is located within the Brecon Beacons National Park with its eastern half in the Merthyr Tydfil unitary authority area and the western half in Rhondda Cynon Taf.
Cardiff Corporation Waterworks
Interactive map not available
Weather at Llwyn-onn Reservoir
H: 71° L: 50°
Clear
52°
|
Feels like 50°
Precipitation
5%
Humidity
64%
Wind
4 mph
UV Index
0
Water Conditions:
🥶Too cold for most swimmers
12 AM
54°
3 AM
51°
6 AM
50°
9 AM
56°
12 PM
65°
3 PM
70°
6 PM
69°
9 PM
62°
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Compare on Amazon →Frequently asked questions
- Where is Llwyn-onn Reservoir?
- Llwyn-onn Reservoir is a reservoir in Wales.
- Can you swim at Llwyn-onn Reservoir?
- There is no fixed answer for Llwyn-onn Reservoir: whether it is safe to swim there on a given day depends on the water temperature, recent rainfall, and any advisories posted at Llwyn-onn Reservoir in Wales. Check current water conditions before you go, and follow posted signs and local guidance.
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Best Times to Visit
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Right Now
Cool weather - dress warmly
🏞️ Lakes Tips:
- ›Check for boat launch facilities and fees
- ›Obtain required fishing licenses before arrival
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- ›Monitor water quality reports before swimming
Best Seasons:
☀️ Summer (Jun-Aug)🍂 Fall (Sep-Nov)🌸 Spring (Mar-May)
Location & Contact
Wales
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