Erdfallsee

Lake Nature Reserve Holy Sea - Heupen

The Erdfallsee is one of the four large still waters of the reserve Holy Sea - Heupen in the district of Steinfurt. He was born on April 14, 1913 by a sinkhole, which a little later was filled with water. He is, unlike the neighboring Great Saints of the sea, only on the ground of the community Hopsten.

• 3.1 plants

Landscape around the lake

The Erdfallsee lies southwest of the provincial road 504 Ibbenbüren- Hopsten and the Great Holy Sea. Is framed by the Erdfallsee heathland and moorland pools, as well as some smaller older and newer Erdsenken. This Erdsenken fill partially depending on the depth periodically with water. The deeper wells are usually available all year filled with water. South of Erdfallsees is the smaller Heideweiher. The Heideweiher may not be caused by a sinkhole, but by Sandausblasungen in the sandy heathland. To the east of the nature reserve flows the sea Becke direction Hopstener Aa. Further afield to the lake grassland areas are divided into the nature reserve. Besides its own for protection they are expected to protect the lakes prior to the introduction of nutrients.

Landscape before formation of the lake

Prior to the creation of the lake in 1913 spread in the area of the later lake a bog and heathland from. The nutrient-poor areas was suitable at that time not to intensive agricultural management, as the harvest returns would have been too low. They were extensively used for grazing with sheep and Plagge down. In the heathland were partly birch and other frugal trees and plants.

Called The Moor, also Hopstener Moor, lowering surface section to the northeast, and today forms a small shallow bay in contrast to the deep basin subsidence.

Origins of the lake

The seven -acre and forty feet deep lake was created on April 14, 1913 18-19 clock by a sinkhole. Was accompanied its formation by water withdrawals and water rises near the surge point. So shall gushed into the air on nearby farms in small water jets up to 15 centimeters. The water level of a Hofbrunnens is risen to 1.50 meters to the flat earth, to be the next day but fell again.

On the little saint sea had a boy who was traveling with a boat, leave the lake, started because the water by 19 clock to boil and simmer.

The sinkhole was not discovered until the next day. First, the Grikes was 20 feet deep, and measured in diameter from 120 to 160 meters. By crashes and siltation he changed his form steadily up to its present appearance.

The cause of the sinkhole is believed that there has been deep underground to leaching of salt, lime and gypsum. After the cavities had become too large, they collapsed and fell on the surface of the ground after. Such Erdabsenkungen usually take many years, so that only inconspicuous Erdmulden arise. The unusual sudden onset of Erdfallsees is attributed to a fault line, which will be explained with warping of the nearby mountain sheep.

The sinkhole lured in the next few days to up to 6000 visitors. The little train Piesberg - Rheine had to overcome Zumwalde to the nearby railway station the influx of visitors with special trains. The owner of the site rose during the rush on visitor entrance fees to visit the sinkhole. Later, when the hole was filled with water, the number of visitors subsided.

In the first years after its creation, the waters were still used for bathing. In today's conservation area swimming is not permitted, however. However, a part of the lake upstream site is still accessible to visitors. There, the trail is signposted, which provides informative insights. For the purpose of visitor management, the area is, however, surrounded by barbed wire.

The waters

The water is very poor in calcium and slightly acidic, which favors biodiversity. The originally oligotrophic lake has been transformed into a partially mesotrophes waters over time due to eutrophication. Besides the natural causes contribute the surrounding arable land and the sea Becke to this change. The rare nutrient-poor habitats in and around the lake are lost. By Nährstoffeinschleppung the lake is the most strongly varying water in the nature reserve.

Plant

To protect the most interesting plants in the nature reserve include the beach oligotrophic Ling societies. The equally rare water - lobelia, which occurred in the 1970s, yet thousands in the lake, has since been greatly reduced. Situated on the outskirts of the lake -to-find reed suffered in recent years strongly Bisamverbiss and the incidence decreased greatly. The shore of the lake is mostly designed as a sandbank. On the shore zones close to alder carr and birch mixed oak forest. There are also extensive bog - bushes.