The Obere Tideelbe floodplain is a nature reserve in the Hamburg districts of Wilhelmsburg in the Hamburg-Mitte district and Billwerder, Spadenland, Ochsenwerder, Kirchwerder, Moorfleet and Tatenberg in the Bergedorf district. The nature reserve is around 246 hectares in size. It is part of the FFH area "Hamburger Unterelbe". The area, which is looked after by the GÖP nature conservation association and the Hamburg e.V. fishing association, has been under protection since 2010 - initially as a 222-hectare "Auenlandschaft Norderelbe" nature reserve (date of the ordinance: February 16, 2010) and was extended in 2016 to its expanded to today's size and renamed. The nature reserve is located in the area where the Elbe splits and extends along the Norderelbe from the Bundesautobahn 1 in the north to the Bunthäuser Spitze in the south, the Dove Elbe to the Tatenberger Schleuse and on the north bank of the Süderelbe to the "Heuckenlock" nature reserve and includes part of the Elbe with the foreland of the dyke as well as the outer dyke areas of Spadenländer Spitze and Kreetsand, which were created in 2001 by back dikes. In Moorwerder, the nature reserve is limited to the undeveloped outer dike areas. Furthermore, the filter basin and the bird protection grove and the part of the Holzhafengraben lying south of the A 1 on the southern Billwerder island are included in the nature reserve. At the mouth of the Georgswerder Schleusengraben, which is connected to the North Elbe via a pumping station, is the Rhee nature reserve. With the expansion of the nature reserve in 2016, additional outer dyke areas in the districts of Ochsenwerder and Kirchwerder were included in the scope of the nature conservation ordinance. The nature reserve is shaped by the Elbe, which is influenced by the tide – the tidal range here is up to 3.5 meters – with its forelands. The course of the river is accompanied by the remains of alluvial forest. The outer dyke areas are occupied by extensive fallow grassland with tall forbs and reed beds. There is a mudflat area on the Spadenländer peak. On the 42 hectare Kreetsand, the construction of around 30 hectares of tide-influenced shallow water areas is planned, in which further tidal flats are to form. A further relocation of the dyke at Ellerholz, like the Kreetsand a former scouring field, is fundamentally possible.