View source for Vaal Dam

{{Short description|Dam in South Africa}}
{{Use South African English|date=July 2024}}
{{Use dmy dates|date=December 2020}}
{{Infobox dam
| name               = Vaal Dam
| image              = View Of The Vaal Dam with 14 Sluice Gates Opened 2010.jpg
| image_caption      =
| name_official      = Vaal Dam
| dam_crosses        = [[Vaal River]]
| res_name           = Vaal Dam
| country            = [[South Africa]]
| location           = Border [[Gauteng]] and [[Free State (South African province)|Free State]]
| owner              = Dept of Water Affairs
| dam_type           = G
| purpose            = Domestic and industrial water
| dam_length         =
| dam_height         = 54.2 m
| dam_width_base     =
| construction_began =
| opening            = 1938
| demolished         =
| cost               =
| res_capacity_total = {{convert|2609799000|m3}}<ref name="dawf-vaal"/>
| res_catchment      =
| res_surface        = {{convert|320|km2}}<ref name="dawf-vaal"/>
| coordinates        = {{coord|-26.89472|28.14555|region:ZA_type:landmark|display=inline,title}}
| location_map       = South Africa
}}
The '''Vaal Dam''' in [[South Africa]] was constructed in 1938 and lies 77&nbsp;km south of [[OR Tambo International Airport]], [[Johannesburg]].  The lake behind the dam wall has a surface area of about {{convert|320|km2}}<ref name="dawf-vaal">{{cite web|url=http://www.dwaf.gov.za/orange/Vaal/vaaldam.htm|title=VAAL DAM|publisher=[[Department of Water Affairs]]|access-date=19 December 2009|archive-url=https://web.archive.org/web/20190626050028/http://www.dwaf.gov.za/orange/Vaal/vaaldam.htm|archive-date=26 June 2019|url-status=live}}</ref> and is 47 meters deep. The Vaal Dam lies on the [[Vaal River]], which is one of South Africa's strongest-flowing rivers. Other rivers flowing into the dam are the [[Wilge River]], Molspruit and Grootspruit.<ref>[http://www.dwaf.gov.za/iwqs/gis_apps/dam/dams/vaal.htm Vaal (reservoir)] {{webarchive|date=22 June 2004|url=https://web.archive.org/web/20040622202853/http://www.dwaf.gov.za/iwqs/gis_apps/dam/dams/vaal.htm}}</ref> It has over {{convert|800|km}} of shoreline and is South Africa's second biggest dam by area and the fourth largest by volume.

==History==
The construction of Vaal Dam started during the depression of the early thirties and the dam was completed in 1938 with a wall height of {{convert|54.2|m}} above lowest foundation and a full supply capacity of {{convert|994000000|m3}}. The dam is a concrete gravity structure with an earthfill section on the right flank. It was built as a joint venture by [[Rand Water]] and the Department of Irrigation (now known as the Department of Water Affairs).

The dam was subsequently raised in the early fifties to a height of {{convert|60.3|m}} which increased the capacity to {{convert|2188000000|m3}}. A second raising took place in 1985 when the wall was raised by a further {{convert|3.05|m}} to {{convert|63.4|m}} above lowest foundation. The capacity of the dam is currently {{convert|2609799000|m3}} and a further {{convert|663000000|m3}} or 26% can be stored temporarily for flood attenuation.

The flood attenuation properties of the dam were severely tested in February 1996 when the largest flood ever recorded at the Vaal Dam site was experienced. An inflow of over {{convert|4700|m3/s}} was measured into the Vaal Dam which was already at full capacity due to good rains and it was only through the expert management of the Hydrology staff at DWAF that the maximum flood released from the dam was limited to {{convert|2300|m3/s}}. Flows above {{convert|2300|m3/s}} would have caused serious damage downstream of Vaal Dam and the situation during the 1996 flood became extremely tense as the storage in the reservoir peaked at 118.5% of Full Supply Capacity on 19 February 1996 i.e. only {{convert|194000000|m3}} of flood absorption capacity remained before the full inflow would have been released causing massive damage.

The [[Lesotho Highlands Water Project]] feeds water into the system by gravity contributing to a stable supply of water to the people and industrial complex of [[Gauteng]]. This water is piped from Lesotho into the [[Liebenbergsvlei River|Liebenbergsvlei]] and [[Wilge River]]s.

The [[Sterkfontein Dam]] forms part of the [[Tugela Vaal Transfer Scheme|Tugela-Vaal water transfer scheme]] for the [[interbasin transfer]] of water from the [[Thukela River]] in [[KwaZulu-Natal]] to boost the levels in the [[Vaal River System]]. Water from the Sterkfontein Dam is released once the Vaal Dam drops to below 16%.

The dam has its own island some {{convert|5|km|mi|0|abbr=on}} long. The island was used as a secret meeting place by the apartheid government but now hosts the annual Round the Island Yacht race, a [[Guinness Book of World Records]] title of the largest inland yacht race.<ref>{{cite web |url=http://www.gauteng.net/attractions/entry/vaal_dam/ |url-status=dead |archive-url=https://web.archive.org/web/20101219034532/http://www.gauteng.net/attractions/entry/vaal_dam/ |archive-date=19 December 2010 |title=Vaal Dam – Attractions – Gauteng Tourism Authority}}</ref>

On 4 May 1948 [[British Overseas Airways Corporation|BOAC]] introduced [[Short Solent]] flying boats on the UK (Southampton) to South Africa (Vaaldam) service.<ref>{{cite web|url=http://www.bamuseum.com/museumhistory40-50.html|title=Museum History 1940–1950|publisher=[[British Airways]] Museum|access-date=2009-07-10|archive-url=https://web.archive.org/web/20081227103220/http://www.bamuseum.com/museumhistory40-50.html|archive-date=2008-12-27|url-status=dead}}</ref> The small village of [[Deneysville]] was used as a stop-over point by the old [[British Overseas Airways Corporation|BOAC]] flying boats.

==Water sports==
The Vaal Dam is a fishing venue for freshwater [[carp]] and [[catfish]]. Its shores are filled with anglers throughout the year.

Many world class water sport events are held here including the annual "Round The Island" yacht race organized by Lake Deneys Yacht Club—<ref>{{cite web|url=http://www.ldyc.co.za/|title=There's much more to LDYC than Sailing|publisher=Lake Deneys Yacht Club|access-date=2009-07-10}}</ref> a race that has been in the [[Guinness Book of Records]] for being the "Most Yachts in an Inland Yacht Race in the World", in which 389 craft crossed the finish line.{{Citation needed|date=July 2009}} This race has entered the Guinness Book of Records for the most boats in an inland yacht race. Several large events take place here including Keelboat Week and the Bayshore 200&nbsp;km [[jetski]] race, and now the Bayshore Marina Vaal Dam Treasure Hunt. Lake Deneys Yacht Club and Pennant Nine Yacht Club partnered the organisation of a fleet which participated in the inaugural 2014 and second 2015 international "Bart's Bash".

Three provinces make up the Dam's shoreline - the [[Free State (South African province)|Free State]] has the longest stretch, [[Mpumalanga]] has a beautiful and relatively unspoilt [[shoreline]], while the most despoiled by far is that of [[Gauteng]]. The dam was commissioned in 1939, has a capacity of {{convert|2.536|km3|acre.ft|lk=out}},<ref name="dawf-vaal"/> and a surface area of {{convert|320|km2}},<ref name="dawf-vaal"/> the dam wall is {{convert|63|m}} high. Due to the large lake size reservoir there is a problem with evaporation, see [[Sterkfontein Dam]] for more details.

[[Deneysville]] is the largest town on the Vaal Dam and provides a shopping centre for the Dam. There are three yacht clubs and two marinas.

==Nature==
The main angling fish species of the Vaal dam are [[Clarias gariepinus|barbel]], [[Cyprinus carpio|common carp]], [[mirror carp]], [[grass carp]], [[smallmouth yellowfish]], [[largemouth yellowfish]] and [[Labeo capensis|mudfish]].<ref name="fa">{{cite web |title=Vaal Dam / Vaaldam (FS) |url=http://www.favisa.co.za/index.php?option=com_content&task=view&id=87&Itemid=226 |website=Fishing and Venues in South Africa |publisher=favisa |access-date=26 February 2016 |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304173140/http://www.favisa.co.za/index.php?option=com_content&task=view&id=87&Itemid=226 |url-status=dead }}</ref> [[Egyptian goose|Egyptian geese]] and [[blacksmith lapwing]] are abundant shore birds, and [[Caspian tern]]s also occur in large numbers. The [[greater flamingo]] is a regular wading bird, with [[lesser flamingo]] present in lower numbers, and vagrant [[African openbill|openbill]]s have been seen. A few dozen [[African fish eagle|fish eagle]]s are present, while [[osprey]] occurs sparsely.<ref name="cwac">{{cite web |title=Registered CWAC Sites: Free State |url=http://cwac.adu.org.za/sites.php?province=Free%20State |website=Coordinated Waterbird Counts |publisher=ADU |access-date=26 February 2016}}</ref>

== See also ==
* [[Vaal River]]
* [[Lesotho Highlands Water Project]]
* [[Sterkfontein Dam]]

== References ==
{{Reflist}}

== External links ==
{{Commons category|Vaal Dam}}
{{External media
| image1 = [http://www.dwaf.gov.za/orange/images/web147l.jpg Vaal Dam] from the South African [[Department of Water Affairs]]
| image2 = [http://www.dwaf.gov.za/orange/images/web147l.jpg Vaal Dam] from the [[Department of Water Affairs]]
}}
* [http://www.randwater.co.za/Education/Edu_Details.asp?ArticleId=48 Rand Water Board] {{Webarchive|url=https://web.archive.org/web/20090207133200/http://www.randwater.co.za/Education/Edu_Details.asp?ArticleId=48 |date=7 February 2009 }}
* {{usurped|1=[https://web.archive.org/web/20030418101945/http://www.deneysville.com/ Deneysville]}}

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[[Category:Dams completed in 1938]]
[[Category:Dams in South Africa]]