In order to keep the large ship­ping route from Stet­tin (Szczecin) nav­i­ga­ble for larg­er car­go ships all year round, to improve the yield of agri­cul­ture in the Oder Val­ley itself and the drainage for the Oder­bruch fur­ther south, the Oder Val­ley, which had been large­ly unde­vel­oped by humans, was replaced at the begin­ning of the 20th cen­tu­ry Dutch plans redesigned. On this occa­sion, today on the Ger­man side, sev­er­al wet pold­ers were cre­at­ed (pold­er A: approx. 1,644 hectares, pold­er B: approx the Hohen­saat­en-Friedrich­sthaler water­way to the west. The for­mer Gartzer Pold­er and the Schillers­dor­fer Pold­er, now the Pol­ish Zwis­chen­oder­land, were designed as wet polders.

The pold­ers are usu­al­ly only flood­ed in win­ter. From April 15th of each year, how­ev­er, they are drained by the nat­ur­al runoff of the water or, in addi­tion, by elec­tric pumps. From a nature con­ser­va­tion point of view, the plan is to keep the flood­ing in the wet pold­ers unaf­fect­ed by humans for as long as pos­si­ble and to keep the inlet and out­let struc­tures open all year round, at least until May 31 of each year.

Water con­di­tions as close to nature as pos­si­ble are essen­tial, espe­cial­ly for a flood­plain nation­al park. A water man­age­ment fea­si­bil­i­ty study com­mis­sioned by the state has estab­lished, at least for the Fid­di­chow­er Pold­er (10), but in prin­ci­ple also for the Criewen­er and Schwedt Pold­er (A / B), that such a year-round open­ing with cor­re­spond­ing restric­tions for agri­cul­ture with­out dam­age to the Flood pro­tec­tion is possible.

After all, twelve years after the found­ing of the Nation­al Park, the small Staffelder Pold­er (8) with a size of 40 hectares has been recon­nect­ed to the waters of the West­oder. The dike sep­a­rat­ing the pold­er from the West­oder was opened in 2008 in three places. How­ev­er, you have to know that the West­oder is not a nat­ur­al body of water and, accord­ing to cer­tain rules, only lim­it­ed water is allo­cat­ed from the Stro­mod­er through the Marien­hofer Weir. Oth­er­wise, the West or the water sys­tem of the Hohen­saat­en-Friedrich­sthaler Wasser­straße is essen­tial­ly at sea lev­el and its flow activ­i­ty is strong­ly influ­enced by the Szczecin Lagoon and the Baltic Sea.