This area is located within the natural landscape unit Ostbraunschweigisches Hügelland (East Brunswick Hills) in the natural geographic region Boerden (Atlantic biogeographic region) in the city of Salzgitter. Lake Heerter was artificially installed – originally as "Klärteich III" ("Sedimentation pond III") - in the 1950s by means of a dam construction. It was used to collect water from the ore washing plant. A saline, nutrient-poor lake of up to 160ha surface and 3m depth was created; it is surrounded by extensive, bare sludge plains. Since 1976, when economic use was suspended, reeds have colonised the sludge areas and the salt content has continually decreased. Bush grass and woody plants have colonised the elevated areas.
The region provides important breeding habitats for reed birds and waterfowl, as well as resting places for shorebirds. It also serves as a foraging grounds for various birds of prey. Of further significance are populations of halophytes located far within the interior, as well as rare plant species of the calcareous grassland. The region is owned by NABU-Stiftung Nationales Naturerbe (NABU Foundation National Natural Heritage).
The currently westernmost population of the European green toad in Lower Saxony is located in this region. The population is isolated to a great extend and thus of utmost importance for the preservation of the species' areal. The European green toad uses the lake shore regions as spawning grounds. In recent years, generally less than ten calling males were identified.
Area size: 272 ha