]> 2026-04-14T11:28:11+00:00 Case study:River Ogwen and Nant Francon 500 en Manual of River Restoration Techniques entry (RRC) Approved Installation of cascades Creation of pools and riffles Yes Yes No Improvement Yes Fish,Yes,Yes,Yes,Yes,No,Improvement Fish Yes Morphology of the bed altered Natural Resources Wales National Trust Environment Agency Great Britain Yes No Yes false Restored Island 1.JPG Restored bed levels and bank profile.JPG Restored Island - Nov 2012 Restored section - Nov 2012 No 53.132470820841,-4.0316561982036 Hugh Natural Resources Wales Jones Installation of cascades, Creation of pools and riffles,,,Morphology of the bed altered ,,, 5986 National Trust, Environment Agency Restored bed level and bank profile following restoration (Nov 2012) Restored bed levels and bank profile 2.JPG 1998-09-01Z 2451057.5 Complete The Ogwen is in a mountainous location of Snowdonia below Llyn Ogwen (Lake Ogwen), and flows northwards through the Nant Ffrancon valley. During the 1960s the river was deepened by dredging over a 4km length downstream of the waterfall in an attempt to reduce the frequency of flooding over the valley floor to improve livestock grazing. Over the following 30 years the river flushed virtually all bed gravels through the system and scoured the river bed and banks. The reach became severely denuded of any stable habitat for flora and fauna, the once thriving salmon fishery declined and flooding was still troublesome to farmers. Four boulder cascades were created and pool and riffle sequences created in the upper reach. Some runs of gravel were introduced and shoals were created on the inside of bends. A major erosion site was reinstated using a willow mattress technique. River Ogwen and Nant Francon river ogwen and nant francon No 900 North West Wales Western Wales Ogwen - upper ogwen - upper River Ogwen river ogwen Salmonids 10 - 100 km² 1036 1000 - 2000 m Ogwen - upper GB110065054160 Of the £48,000 (€56,000) project cost- £8,000 (€9,300) was spent on a flood model and £5,000 (€5,800) was spent on design. Fisheries Flood risk management Land use management - agriculture 56 50 - 100 k€ GB110065054160 Ogwen - upper 1998-11-30Z 2451147.5 2013-07-08T15:28:09Z 2456482.1445486 2015-10-23T15:14:41Z 2457319.1351968 River Ogwen and Nant Francon 500 1 plainlist 5 [[Category:Case study]] [[Project title::!River Ogwen and Nant Francon]] [[Subcatchment title::Ogwen - upper]] River Ogwen and Nant Francon# QUERYb5ffab5e2c9ffebf6a448c2a3925e8b6