Groundwater lakes are mainly the result of dredging in eastern Austria. They are often subject to intensive use by bathing guests or by fisherman, which harbors the danger of eutrophication and thus of impairment of the groundwater. For many years DWS Hydro-Ökologie has been providing predictions of the trophic development and offers limnological management concepts in order to maintain a good water quality, as for example at planned groundwater lakes near Euratsfeld, at Untersiebenbrunn, at the gravel lakes Viehofen, at Aignerteich near Guntramsdorf, at Steindleich, at several so-called brick ponds south of Vienna and at Reiterersee near Wr. Neustadt.

Clients: Municipalities, water cooperatives, private clients

In February 2022 dredging works took place in the reed belt of the Wulka estuary in Lake Neusiedl. DWS Hydro-Ecology accompanied the measures during the planning process and as part of a monitoring, in order to implement the REBEN management plan’s proposals for the sustainable preservation of water quality.

Clients: Amt der Bgld. Landesregierung, Esterhazy Betriebe GmbH

As part of water management measures restoration of structures and passability for the Traisen near Pottenbrunn was implemented between level 13 and 17. To clarify the efficiency of the measures an ecological monitoring was carried out to estimate the good ecological potential and modelling data were checked with regard to stable river morphological development.

Tasks: Phytobenthos and macroinvertebrate investigations, reports

In ccoperation with ezb, TB Spindler

Client: Traisen Wasserverband

As ordered by the Bgld. Landesregierung and in co-operation with the fishing district tenants in Burgenland and Lower Austria, DWS Hydro-Ecology developed a fishing management concept, which aims at enabling an agreed and sustainable fishery at the river Leitha.

Client: Amt der Bgld. Landesregierung

In 2015, DWS Hydro-Ecology was asked to carry out basic hydrological and limnological investigations in the river system of Schwechat and Baden Mühlbach. The aim of the study was to make a proposal for residual flow for the river Schwechat downstream of the ‘Helenenwehr’ in order to restore the river continuum. The analyses included flow measurements, calculations of chemical immission and hydrological modelling.

Client: Amt der NÖ Landesregierung

Tasks: Ecological consulting for the construction of fish passes at the river Pinka according to the requirements of the Guidance of the BMNT

Client: Amt der Bgld. Landesregierung

The Upper Lobau is closely interlinked with the settlement area of ​​Vienna and due to various factors highly endangered in terms of its natural value. There are serious deficits in the water supply of the oxbows, which were partly compensated with the total stowage of Freudenau and the dotation of the Upper Lobau via the upper reservoir of the New Danube and the Old Danube, but could not be completely eliminated. The aim of the present study was to investigate possibilities for improvement of the water supply of the Upper Lobau by dotation of the surface waters via a connection of the Panozzalacke to the lower stowage area of the New Danube. The broader goal in this context was to safeguard the biodiversity of the landscape type and to preserve the landscape character of relict arms with its diverse autochthonous flora and fauna in the Upper Lobau. The individual examined and illustrated variants entail different ways of future water supply.

In cooperation with DonauConsult

Tasks: Assessment of the dotation variants from ecological and nature conservation point of view

Client: MA45- Wiener Gewässer

Urban waters are of particular importance because of their value as a recreational area for the population. Morphology, hydrology and nutrient inputs affect functional biotic loops, which in turn dampen or accelerate internal fluxes. When a new water body is artificially created, a prediction for its development can be made if general conditions as well as aquatic ecological principles are taken into account. Optimal planning can ideally create a water body with a low trophic level and a low eutrophication potential.

In the master plan “Flugfeld Aspern” a park with an open water surface had been planned as a structure-forming element in the middle of the building area. From 2010 to 2014, the approx. 5 ha large, groundwater-fed pond was converted into the future urban district “Seestadt Aspern”.

Tasks: Consulting during the planning phase, water ecological monitoring after construction of the pond (nutrient chemistry, phytoplankton)

Client: MA45 – Wiener Gewässer

The Neusiedler See region is a nature conservation hotspot and at the same time subject to manifold uses. In 2013, DWS Hydro-Ecology was commissioned with the preparation of an interdisciplinary, bilateral strategy study, with the objective to identify ways of securing the ecological and economic potential of the cultural landscape of Lake Neusiedl in the long term. The study involved more than 50 experts. It included an inventory of the status quo and a deficit analysis as well as a comprehensive catalogue of measures for the subjects of water management, limnology, nature conservation and spatial planning.

Client: Austrian-Hungarian Water Commission

As part of the implementation of the EU Water Framework Directive, several fish passes were built on the river Rabnitz in central Burgenland in 2013. The aim was to restore the river continuum for migratory fish species.

Tasks: Fish-ecological monitoring (electro fishing, assessment, expert report)

Client: Amt der Bgld. Landesregierung

As a consequence of the intensive growth of macrophytes, which has started in 2002, the buffering capacity for photosynthetic pH fluctuations in the Old Danube has decreased . Since a water exchange with the New Danube did not have a long-term effect, DWS Hydro-Ecology was commissioned to develop variants for a sustainable increase in buffer capacity and to examine their technical and structural feasibility, taking into account the cost-benefit aspect (eg. Partial stream from the Irissee, discharge of New Danube water via the Wasserpark).

Client: MA45 – Wiener Gewässer

Options of endowment of Lake Neusiedl with alien water have been discussed for a long time. In 2009, the Austrian-Hungarian Waser Commission instructed the TU Vienna (under the lead of Univ.Prof. Dr. Matthias Zessner-Spitzenberg) with a research study on possible impacts of a water supply from the Rába river into the lake. The study was carried out in co-operation with Hungarian colleagues (TU Budapest). The tasks of DWS Hydro-Ecology within this project were to calculate matter balances for Lake Neusiedl (chloride, phosphorus, nitrogen). The results were presented in a Technical Report and a scientific publication.

Tasks: Statistical data analyses and modelling of matter balances for Lake Neusiedl

Client: Technical University Vienna

The interdisciplinary study under the lead of DWS Hydro-Ecology aimed at assessing, in various scenarios, the ecological impact of an endowment of Lake Neusiedl with water from the rivers Danube or Raba. The expert study was carried out together with experts in hydrology, chemistry, fish ecology, vegetation ecology and ornithology.

Client: Amt der Bgld. Landesregierung, Federal Ministry of Agriculture and forestry, Environment and Water Management

Regional pilot project for the sustainable development of streams and ditches in the Pannonian field, exemplified in the consolidation area of Leithaprodersdorf at the Natura 2000 site Johannesbach – basic limnological and vegetation ecology study

Tasks: Investigation of makrozoobenthos, phytobenthos and fish; in cooperation with AVL (Terrestrial vegetation), Mag. Iris Fortmann (hydro-morphology), DI Thomas Ofenböck (unionid mussels), the Museum of Natural History / Dr. Ernst Mikschi (fish ecology) and DI Dr. Cecil (public relations)

Client: Municipality of Leithaprodersdorf / Government of Burgenland