Frequently asked questions about our fish pass

From an economic point of view, the Fishcon lock is particularly suitable for heights from 1.5 m. With the standard versions, attraction flow rates of approx. 30 bis 600 l/s can be achieved and heights of max. 6 m can be overcome. Adaptations or special designs are possible for larger amounts of water or heights. In principle, a combination of several Fishcon locks or with conventional fish passes is also possible in order to overcome great heights, or a combination with the use of hydropower, for example to ensure to be easily found in large areas.

The migration of over 30 species of fish has already been demonstrated. That includes weak swimmers, sole-dwelling species and schooling fish.

Yes, the functionality of both pilot plants could be verified by monitoring studies. The monitoring reports with the very positive and meaningful results can be requested from Fishcon.

With the Fishcon lock, two lock chambers are combined in such a way that fish ascent and descent are possible at the same time, as well as simple operation with low water requirements.

The function for the fish is identical to that of a conventional fish lock. An ascending fish, for example, follows the guiding current from the downstream water into the chamber that is open to the downstream water. The fish can move freely in the entire chamber because it is always completely filled with water. Then the downstream slide gate of this chamber closes and the upstream slide gate opens. Guided by a new attraction flow, the fish can swim out of the chamber into the upstream water.

Detailed information on the function can be found on this website under “Fishcon pass”. If you have any questions, please feel free to contact Fishcon!

Yes, although the upstream waterway connection must be designed accordingly in order to enable the fish migrating downwards to be found.

The connection for the fish descent should, for example, be as close as possible to the main flow obstacle to migration. Fishcon will be happy to assist you in planning the optimal waterway connection.

The slide gates can be moved with electric or hydraulic drives. The electric drives work with a supply voltage of 24 VDC or 230 VAC and are particularly suitable for small systems. For larger systems hydraulic drives are recommended in which the hydraulic unit has to be supplied with 400 VAC three-phase.

The energy requirement of the slide gates or the entire system is very low at a few 100 kWh/a.

Fishcon’s fish pass is known by both names and provide the same technology. In the scientific field and in specialist literature, the name 2-chamber organism migration aid was mainly used until 2020. In marketing reasons, the name Fishcon fish pass is usually used.

The operating experience of the existing systems indicates a very low-maintenance operation because there are hardly any bottlenecks that could lead to a blockage. Nevertheless, it is recommended to design the surface water connection in such a way that no large amounts of floating or suspended matter are brought in. This can be achieved, for example, by means of an inlet slot element, a dip wall or a baffle screen.

In addition to regular visual inspections, it is recommended to inspect the system once or twice a year. For this purpose, the upper water basin has to be emptied, to look into the chambers. Such an inspection can be carried out in about an hour if the waterway connection is designed accordingly.

The Fishcon lock can detect a flood by means of a float switch or an external input signal. The recommended upstream and downstream water basins can also be well protected by covers with, for example, press-locked grating. The Fishcon lock is designed in such a way that it can be completely overflowed apart from the control box. Rinsing is possible after the flood if larger amounts of bed load enter the basin despite the system shutdown.

The Fishcon lock can be operated with very small amounts of water, such as 40 l/s, as well as with staggered additions depending on the season or the inflow. The amount of attraction flow water required is heavily dependent on the size of the body of water and can be individually adapted to the location of the Fishcon lock.

In general, attraction water quantities of around 1-5% of the competing run-off are recommended in order to enable large-scale traceability with good design of the waterway connection. Fishcon will be happy to help with the design!

The prices of the Fishcon lock depend primarily on the length of the size-determining fish species at the location. Other small influences have the length of the lock, the height difference to be overcome and the specific design of the fish lock (with turbine or throttle …). We will be happy to estimate the costs for your location or send you an offer.

Yes, at locations with slightly higher heights and volumes of attraction water, economic operation is possible, and in some cases very profitable.

The choice of the right fish pass depends very much on the general conditions of the location. In the case of very small height differences, conventional fish passages can be the cheaper solution. The Fishcon lock is often advantageous for heights of approx. 1.5 m or more, because the costs and water requirements are usually lower, the system requires very little space and is insensitive to floods and fluctuating water levels.

Another great advantage is that the Fishcon lock, due to its compact design, creates an optimal connection for the fish descent and this can be implemented via the Fishcon lock.

For the Fishcon lock to function, an optimal water connection is of decisive importance. As with conventional fish passes, the connections should be as close as possible to the migration obstacle on the bank of the side with the main flow. In order to be able to dry out the system for maintenance purposes, it is advisable to provide a lockable basin before and after the Fishcon lock. The upstream connection should be designed in such a way that flotsam is kept away from the system. Fishcon will be happy to help you with the planning!

The construction costs depend heavily on the location. For simple locations, implementation is possible in a few days, as was the case, for example, with the Fishcon lock on the Aschacharm (construction time: 7 working days; construction costs: approx. € 12,000).

Due to the prefabrication in the factory, on-site assembly is possible in one day.