Portrack Marsh Nature Reserve is a 50 acres reserve by using the northern financial institution of the River Tees between the Tees Barrage and the Tees Viaduct, near Portrack housing property in Stockton-on-Tees borough, County Durham. It is the ultimate wetland on the lower Tees. The website is bounded by using Marston Road, a disused railway line, the Northumbrian Water's waste water remedy website, the River Tees, the Tees Barrage White Water Course, the grounds of The Talpore pub and a Tees Barrage access road.
Ownership of the reserve is split between Tees Valley Wildlife Trust and Northumbrian Water however the reserve is controlled by means of Tees Valley Wildlife Trust. The reserve in the west and north is mature marsh while there are a series of guy–made ponds inside the the rest. The web site is at an altitude of 10 metres over datum. The reserve has some of ponds – inside the north is Mallard Water, in the east Teal Lake and through the River Tees alongside the southern boundary, Willow Pond, and Darter Ponds with its dipping platform, and within the western half of, West Water with its islands – a few ponds are especially shallow and a few deep. In the north-east and far west of the reserve are areas of grassland.