River Usk River Usk The River Usk (; ) rises on the northern slopes of the Black Mountain ("y Mynydd Du"), Wales, in the westernmost part of the Brecon Beacons National Park. Initially forming the boundary between Carmarthenshire and Powys, it flows north into Usk Reservoir, then east by Sennybridge to Brecon before turning southeast to flow by Talybont-on-Usk, Crickhowell and Abergavenny after which it takes a more southerly course. Beyond the eponymous town of Usk it passes the Roman legionary fortress of Caerleon to flow through the heart of the city of Newport and into the Severn estuary at Uskmouth beyond
River Ouzel and Clipstone, and to the north of the town the excess water from the canal is released into the river at the Twelve Arches. The river then flows through Milton Keynes, where it is joined by Water Eaton Brook, and as it exits the town it is joined by Crawley Brook from Husborne Crawley. Finally, the river flows through Newport Pagnell to its junction with the Great Ouse. River Ouzel The River Ouzel , also known as the River Lovat, is a river in England, and a tributary of the River Great Ouse. It rises in the Chiltern Hills and