In our rivers there are a lot of hydropowerstations, sluices and weirs hindering the migration of many waterorganism. 
Projects like Aller-Oker-Salmon, Schuntersalmon or the "Aktion Fischotterschutz" (campaign otterprotection) try to effect the public interest with symbols as Salmon or Otter .

These sites are to give an overview on such obstructions in German y and the netherlands. The area in lower saxony with the rivers Aller, Oker, Schunter and Oertze is quite well described. The description is completed with central obstructions in other german rivers und their fishmigrationinstallations. In addition there are filled in own knowledges - comments of the internet-community are likely to be seen.  So your knowledge is asked for to perhaps get a better understanding for more people on the whole subject.
In advance on the EU-waterframework directive (Thinking an working along the rivers) it could be possible to develope an entire concept  for the patency of rivers  - up- and downstream.
An additional attendent to this plan is the Aller - Oker -Lachs-Gemeinschaft (AOLG) english: Aller-Oker-Salmon-Association. This association tries to bring together landowners - Fishingassociations, Fischingcooperatives and Waterassociations under one roof to find synergetic proposals for the reintroduction of Atlantic Salmon in the watershed of the Aller.    
The base of this documentation is the knowledge of the "Fliessgewaesserschutzsystem" english : Riverprotectionsystem of the "Niedersächsischen Landesamt für Ökologie (NLÖ - today LAVES)", english : Countryoffice of lower-saxony for ecology, in the year 1990. Informations about rivers outside of lowersaxony in Germany have the same layout but the base is not derived by an offcial documentation.
Initiated by the start of the Project "Schunterlachs" ,english: Schuntersalmon, I made a journey along the Aller in April 2002, the findings of this journey were put into this homepage. To make this dokumentation more lively may anbody give actual informations to me so i can update this sites for a better understanding of the problems that waterorgansim have.
Legend :        S1   clickable Migrationobstacle of the NLOE - Riverprotectionsystem
                       N1  clickable Migrationobstacle  - new development
                       S1   complete free migration because of very good migrationdevice up und down 
 

Keeper of the river in "Angel- und Gewässerschutzvereins Wolfsburg-Vorsfelde"english: Fisching-and Waterprotection Association Wolfsburg-Vorsfelde, and Member of the Salmonboard of the Aller-Oker-Salmon-Association


Stefan Ludwig