artificial barriers data sheet.xlsx

Results of the assessment of fish passability through artificial barriers using Rapid Barrier Passability and Hydropower Assessment Tool (https://amber.international/software/).

 As per this protocol, the parameters of the barriers measured included: DH – drop head, the height difference between the upper and lower water table (used interchangeably with barrier height); H – water depth at the crest of the barrier; Hf – water depth below the barrier; Wt – width of the barrier head; Df – height difference between the lower water table and lower part of an inclined weir; slope – tilt of barrier surface. Measured parameters refer to the state of the barrier in the moment of measurement. Almost all parameters would change under different flow conditions and if the position of movable part of the barrier was altered. 

The ICE protocol determines passability class basing on a decision-tree scheme, with six steps of various thresholds values. When a threshold for a DH is passed, the decision tree goes to the next threshold about H, etc. There are 20 ICE species groups based on different fish species abilities. Passability class was therefore scored for 47 fish species in 20 groups.

The fish passability score was divided into 4 classes: 0 – no fish of the species is able to pass the barrier, 0.33 – only the strongest fish in good condition can pass the barrier with this causing delays in migration, 0.66 – over half of the species population is able to pass the barrier, although it causes delays, 1 – most fishes of a given species are able to pass the barrier, although it still can cause a delay in migration.