31:[{"id":"c263b00e7574b3e4ecc21be01349ad43f89e52fb7606d14793ade342cecf02fb48db228a6ec747aa4ae361b0bcb06af6b50baf3c65e52d17fcd6e809077fdb45","href":"https://static.observableusercontent.com/files/c263b00e7574b3e4ecc21be01349ad43f89e52fb7606d14793ade342cecf02fb48db228a6ec747aa4ae361b0bcb06af6b50baf3c65e52d17fcd6e809077fdb45","name":"layout.jpg","type":"image/jpeg","lastModified":1583413642826.18,"size":310168},{"id":"244631af86436f754038a6f5bef2ed490a5ee6578855394022ae4c59a7e09e70b772b71d5cabec9407a0583550157475759ac611eb8fca91513fa1e44c0f5a36","href":"https://static.observableusercontent.com/files/244631af86436f754038a6f5bef2ed490a5ee6578855394022ae4c59a7e09e70b772b71d5cabec9407a0583550157475759ac611eb8fca91513fa1e44c0f5a36","name":"area.jpg","type":"image/jpeg","lastModified":1583416402859.649,"size":157825},{"id":"88e9be28e3cefb28d983343fce79d1d0ba66f3e93dd066d8e35108b62514afe9948cbad64ef83103d463c77740f82d678cc1588e1c914c2eebce7da1284f2fe1","href":"https://static.observableusercontent.com/files/88e9be28e3cefb28d983343fce79d1d0ba66f3e93dd066d8e35108b62514afe9948cbad64ef83103d463c77740f82d678cc1588e1c914c2eebce7da1284f2fe1","name":"ESIA_01_General_Location.png","type":"image/png","lastModified":1583414204440.436,"size":263129},{"id":"92337e2d1ca37d73c5bcf468481e1c8562ac7be20b2bdb4aec69c0efc970c5e3f488b966b057f42643fba894f0a658bb952cbfd61a83577235e25563b679e8f8","href":"https://static.observableusercontent.com/files/92337e2d1ca37d73c5bcf468481e1c8562ac7be20b2bdb4aec69c0efc970c5e3f488b966b057f42643fba894f0a658bb952cbfd61a83577235e25563b679e8f8","name":"headworks.jpg","type":"image/jpeg","lastModified":1583418614759.218,"size":159790},{"id":"f1d91479fba5806a60af2e600c42f293f3238aa573f420fe6d4bda460e81500e74d3dcc787abc26629caac1bd8e7c702a2cd3377dfa1c029025ddbf4d617d5c9","href":"https://static.observableusercontent.com/files/f1d91479fba5806a60af2e600c42f293f3238aa573f420fe6d4bda460e81500e74d3dcc787abc26629caac1bd8e7c702a2cd3377dfa1c029025ddbf4d617d5c9","name":"headworks_sim.jpg","type":"image/jpeg","lastModified":1583419105112.948,"size":84310},{"id":"94be80396942a8bcd62d78fc75e07bbc929505227624b474ba2b8bdf1efcfffec395839a128e52bfee0dad793153c9c9f645d7f086600efde1354ccf4863b0c5","href":"https://static.observableusercontent.com/files/94be80396942a8bcd62d78fc75e07bbc929505227624b474ba2b8bdf1efcfffec395839a128e52bfee0dad793153c9c9f645d7f086600efde1354ccf4863b0c5","name":"canal.jpg","type":"image/jpeg","lastModified":1583419635129.016,"size":158721},{"id":"534bfc413b77773b945b23381491e280933f56f6f987868b79ff941bb204581a038f6e7efa287ec7a4aba2834e5a00ee2da9a741aeafda30fa25a062b16068cb","href":"https://static.observableusercontent.com/files/534bfc413b77773b945b23381491e280933f56f6f987868b79ff941bb204581a038f6e7efa287ec7a4aba2834e5a00ee2da9a741aeafda30fa25a062b16068cb","name":"powerhouse.jpg","type":"image/jpeg","lastModified":1583420020276.491,"size":54432}] 2f:{"title":"Design and Operation","cells":[{"id":0,"value":"html`\n

Design and Operation

Ngonye Falls Hydroelectric Project

\n${book_index('design-and-operation')}\n\nThe Ngonye Falls Hydroelectric Project is a run-of-river electricity generation project on the Zambezi River currently under development by Western Power Company. It seeks to utilise the potential of the Ngonye Falls by diverting water from above the falls and passing it through hydropower turbines before returning water to the river four kilometres downstream.\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":25,"value":"html`\n

Location

\n\nThe Ngonye Falls power project is located on the Zambezi river near Sioma town, about 345km upstream of Victoria Falls and 120km upstream of Sesheke in the Western Province of Zambia.\n`\n","pinned":false,"hidden":false,"mode":"ojs"},{"id":166,"value":"html`\n

\n\n \n\n

Interactive map of the location of the proposed Ngonye Falls power project on the Zambezi river in the Western Province of Zambia. Click here for a fullscreen version.

\n\n\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":47,"value":"html`\n\nUpstream of the Ngonye Falls, the Zambezi River is broad and shallow as it flows through sandy soils from the Barotse Floodplain in the north. Above the falls the river splits into two larger main channels and a series of smaller, narrow braided channels between a number of islands before it flows over the Ngonye Falls. The set of waterfalls that make up the Ngonye Falls are spread in an arc which is approximately 1 km wide, fed by the various channels. Below the Falls are a series of white-water rapids as the river becomes hemmed into a deep narrow gorge cut into weathered sandstone. \n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":52,"value":"html`\n

The Zambezi river and Ngonye Falls leading into the downstream gorge.

\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":20,"value":"html`\nExisting infrastructure in the area includes the recently built major road which runs from Sesheke to Senanga and crosses the river over the new Sioma Bridge about 1.5 km downstream of the Project’s powerhouse. The site is also adjacent to the existing 66 kV electricity transmission line which supplies power to the Western Province from Sesheke.\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":58,"value":"html`\n

Power Station Design

\nElectricity will be generated by diverting some of the river flow into a 3km long canal to a powerhouse in the gorge downstream where turbines will be spun by the water and in turn drive generator units.\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":130,"value":"html`\n

\n\n \n\n

Interactive map of the layout of the proposed Ngonye Falls project. Click here for a fullscreen version.

\n\n\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":62,"value":"html`\n

Headworks

\n\nThe headworks include all of the infrastructure built in the river upstream of the falls. The headworks comprise a series of overtoppable weirs and embankments in the western channel of the river and a concrete barrage in the eastern channel.\nThe headworks are designed to:\n

Hold the level of water upstream of the power station at a constant level of 990m above sea level.
Contain adjustable crest-level weirs that can be dropped to allow flood flows to pass (without causing significant flooding upstream)
Contain weirs to constantly pass the required Environmental Flow Requirements to maintain the ecology and habitat between the weir and powerhouse.
Contain fish passages to allow fish to pass up and downstream past the power station

\nThe headworks divert a portion of river’s total flow through the intake structure and into the power canal.\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":81,"value":"html`\n

A visualisation of the headworks weirs. The EWR weir sections constantly release environmental flows. The flood weirs are lowered during high flows to allow flood flows to pass the power station.

Design and Operation

Ngonye Falls Hydroelectric Project

Location

Power Station Design

Headworks

Canal

Powerhouse

Appendix

Libraries