The document proposes a solution to restore connectivity for fish migration over a spillway sill near the City Hall of Oradea, Romania. The solution involves installing a system of four winches, cables, and a rubber texture near the sill. The texture would be raised and lowered by the winches to carry fish over the sill. An electric motor attached to the river banks would power the winches. The solution aims to improve biodiversity by allowing longitudinal movement of migratory fish species along the Crisul Repede River while avoiding expensive modifications to existing infrastructure.

1. Acta Oecologica Carpatica
DEVELOPING A SYSTEM FOR FISH FAUNA MIGRATION
ABOVE THE SPILLWAY SILL NEAR
THE CITY HALL OF ORADEA
Răzvan VOICU 1 , Liliana VOICU 2
KEYWORDS: ecobiome’s functionality, ecosystem, Crisul Repede River, connectivity,
dynamics of the watercourse
ABSTRACT
In the Oradea town, the watercourse Crisul
Repede underwent morphological alterations
with a negative impact on the dynamics of
the watercourse. This river is provided with
a lot of spillway sills inside the town and,
according to the case study, one of them is
near the centre of the town. The channelled
of the river Crisul Repede inside the town
affected biodiversity and implicit the
ecobiome’s functionality on the Crisul
Repede River.
Therefore, this article aims to
provide a solution for migration fish fauna,
designed to restore longitudinal
connectivity.
REZUMAT:
In orasul Oradea, cursul de apa Crișul
Repede a fost supus alterarilor
hidromorfologice cu impact negativ asupra
dinamicii cursului de apă. Pe sectorul de râu,
care strabate orașul Oradea se află
numeroase praguri deversoare, și potrivit
studiului caz, prezentat in aceasta lucrare,
unul dintre aceste praguri este amplasat
aproape de centrul orașului. Canalizareaa
raului Crisul Repede in interiorul orasului
Oradea afectat biodiversitatea locală si
implicit funcționalitatea ecobiomului de pe
râul Crișul Repede. Prin urmare, acest
articol isi propune sa prezinte o solutie
pentru migrarea ihtiofaunei, menita sa
restabileasca conectivitatea longitudinala.
INTRODUCTION
There are many hydrotechnical
facilities along the Crisul Repede River,
including spillway sills. In the city of
Oradea there are some sills with the
following locations: CFR Bridge, the City
Hall of Oradea, Dacia Bridge etc. These
spillway sills seriously affect the
connectivity of the Crisul Repede River,
strongly reducing its biodiversity and
ecological valence, implicitly. The need for
longitudinal connectivity of watercourses
represents an essential condition for the
Water Framework Directive approved by the
European community and, therefore, it
should be applied to all streams containing
migratory species. The subject of this case
study proposes an ecotechnical solution
consisting of the frontal connectivity in the
city of Oradea. The solution proposed for
fish fauna migration upstream – downstream
of the spillway sill situated at the City Hall
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2. Acta Oecol. Carpat .
of Oradea is practical, it can be developed
without any expensive technology and does
not affect the spillway sill structure and
associated construction.
THE SOLUTION PROPOSED FOR FISH FAUNA MIGRATION
To ease the migration of
ichthyofauna above the spillway sill (figure.
1 and figure. 2), a system consisting of four
winches provided with waterproof metal
cables should be developed. A rubbery
inelastic texture provided with rhombic
space is connected to the cables of the
winches. When it is raised, the texture will
hold the fish fauna (figure.3).
Figure 1: Spillway sill near the City Hall of Oradea
Figure 2: Spillway sill near the City Hall of Oradea
A. Reif, E. Ruşdea, K. Brinkmann, G. Harth, B. Michler, F. - 2 - Păcurar and I. Rotar

3. Acta Oecologica Carpatica
metal circles
stainless cable
stainless cable
Figure 3: Rubbery inelastic texture provided with rhombic space – indicative scheme
On the edge of the texture there is a metal cable on which four symmetrical metal rings
are welded. (figure. 3). Two metal or concrete pillars are fixed on the Crisul Repede River
watercourse on both sides of the spillway sill. (figure. 4).
jagged metal beam
Crisul Repede
River
concrete pillar spillway sill concrete pillar
Crisul Repede River
Figure 4: Positioning metal or concrete pillars– indicative scheme
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4. Acta Oecol. Carpat .
A jagged metal beam is fixed on the
two pillars on inclined plane. (figure 4). An
electric rack-driven motor is fixed in the
upper side of the jagged metal beam. (figure
5). The metal rectangular housing of the
electric motor is fixed on the jagged metal
beam by the means of four bearings.
electric motor
jagged wheel
jagged metal beam
electric motor
jagged wheel
metal bars
bearings
jagged metal beam
Figure 5: Attaching the electric motor to the jagged metal beam– indicative scheme
Due to rack that spins the motor goes
up and down on the jagged rail. Both
upstream and downstream the maximum
distance at which the electric motor can
come close to the two piles is about one
meter. Four winches like those used for
SUVs are attached to the flat edges of the
electric motor housing (figure 6 ).
A. Reif, E. Ruşdea, K. Brinkmann, G. Harth, B. Michler, F. - 4 - Păcurar and I. Rotar

5. Acta Oecologica Carpatica
flat edge of the electric motor housing
winch
Figure 6: Positioning of the winch on the electric motor – indicative scheme
Also, on each edge of the motor
housing, a spacer is welded a few inches
below the winch. On the main bar each
spacer is provided with a mobile cylinder
helping with the traction (figure 7).
mobile cylinder
main bar of the spacer
metal stops mobile cylinder
main bar of the spacer
flat edge of the electric motor housing
Figure 7: Positioning the spacer– indicative scheme
Spacers help winches and dragging
cables function. Therefore, cables do not
interfere with each other and can raise the
rubbery texture provided with rhombic
spaces (figure. 8).
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6. Acta Oecol. Carpat .
concrete pillar
jagged metal beam
spillway sill Crisul Repede River
concrete pillar
rubbery texture provided with rhombic spaces metal cable
winch
electric motor
Figure 8: Positioning the electric motor– indicative scheme
The electric motor is supplied with
electric power from the right bank of the
river, the place where the local electricity
supply is located (figure 9).
A. Reif, E. Ruşdea, K. Brinkmann, G. Harth, B. Michler, F. - 6 - Păcurar and I. Rotar

7. Acta Oecologica Carpatica
power supply arched cable electric motor
jagged metal beam
Crisul Repede
River
concrete pillar spillway sill concrete pillar
power supply fixed cable
Figure 9: Power supply system of the electric motor– indicative scheme
The motor will be supplied by the
means of a fixed cable near the jugged bar.
Then, the fixed cable turns into an arched
cable that can be extended up to the spillway
sill. Surveillance cameras will be installed
on both banks of the river in order to
observe various species of fish gathering
together near the sill, at the rubbery texture.
The electric motor and the winches are
connected to a computer and thus they can
be activated from tens of kilometres distance
by the means of some informational
programs. For migratory fish species to
reach the rubbery texture some
electromagnetic fields systems will be set
using floating generators obliquely
positioned on the spillway sill (figure.10).
The advantage of this solution is the
possibility to be applied in almost any area
of the world, it has an average execution
cost, low maintenance costs and, in the case
of invalidity, the technology already
installed can be transferred to another
spillway sill in another area.
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8. Acta Oecol. Carpat .
jagged metal beam concrete pillar
spillway sill Crisul Repede River
electromagnetic fields generator
Figure 10: Positioning the electromagnetic field generators– indicative scheme
CONCLUSION
This system of fish migration
upstream – downstream of the spillway sill
provides longitudinal connectivity of the
Crisul Repede River representing an
important issue in the local lotic ecosystem
restoration. The solution proposed in this
paper is practical, it can be developed
without any expensive technology and does
not affect the spillway sill structure and
associated construction.
REFERENCES
A. Reif, E. Ruşdea, K. Brinkmann, G. Harth, B. Michler, F. - 8 - Păcurar and I. Rotar

9. ActaOecologica Carpatica
Banarescu, P. Fauna of P.R. R.. Academy Edition, Bucharest ,1964. (in Romanian).
Diaconu S., Cursuri de apa. Amenajare, impact, Reabilitare, Editura *H*G*A, Bucuresti, 1999.
AUTHORS:
¹Răzvan VOICU
rzvnvoicu@yahoo.com
getiiliberi@gmail.com
I.N.H.G.A., Bucharest
²Liliana VOICU
biolili_80@yahoo.com
I.N.H.G.A., Bucharest.
.
Vegetation patterns and land use systems in a traditional cultural landscape; 79/140 pp. - 9 -

10. Acta Oecol. Carpat. .
C. Costiniuc - 10 - and G. Davideanu