34 | INTERPRAEVENT 2016 – Extended Abstracts IP_2016_EA081
INTRODUCTION
In Bavaria building and maintenance of torrent protection structures is basically a compulsory task of the state. To protect the local residents and important infrastructure facilities, many structures were built in the torrent catchment areas over the last 150 years. A periodical monitoring and - if required - maintenance of the existing structures in the about 500 torrent catchment areas is even more important than the building of new ones.
The experiences of the last flood events causing damages displayed, that it is not only necessary to monitor the protection structures, but also to document the monitoring, its results and if any measures were implemented.
On the basis of the Austrian ONR 24803 „Schutz- bauwerke der Wildbachverbauung - Betrieb, Überwachung und Instandhaltung“ an administra- tive guideline about self-monitoring was worked out, considering the different responsibilities and administration structures in Bavaria. The state- ments of the German DIN 19663 „Wildbachverbau- ung“ in terms of self-monitoring of protection structures were specified in this guideline.
The self-monitoring is documented in the database of torrent control structures, which is utilized in the whole Bavarian alpine region.
DATABASE OF TORRENT CONTROL STRUCTURES
Several years ago a database for torrent control structures was developed in Bavaria. The local Water Managing Authorities (Wasser-
wirtschaftsämter) were heavily involved in this process, with the result that a practice-oriented tool came up.
In 2006 the Water Managing Authorities started to gather the basic data (type, coordinates, dimen- sions, etc.) of all torrent structures. The stocktaking is finished in the meantime. Now there are more than 50.000 protection structures recorded in the database, which all were evaluated concerning
their condition. In addition to that there are about 20.000 further buildings like bridges, fords or pipeworks registered in the database.
The database of torrent control structures was extended to implement the strategy for self-moni- toring. The module for self-monitoring enables to generate monitoring-reports automatically based on the contents of the database. The filled in reports are stored in the database afterwards.
STRATEGY FOR SELF-MONITORING IN BAVARIA
Following the ONR 24803 all structures are catego- rized in „key protection structures“ and „standard protection structures“. Key protection structures are treated as single buildings in the sense of the guideline. The standard protection structures are arranged in reasonable monitoring sections. Moni- toring sections of an extra high relevance concern- ing the protection goods or the remaining protec- tion system (e.g. structures in the built-up area or a series of large check dams) are called „main protec- tion units“, the remaining ones „basic protection units“. In addition to the ONR the monitoring sections were introduced, facing the demand of practitioners to regard standard protection struc- tures in their functional correlation. The differen- tiation in main and basic protection units enables to indicate if a group of structures is more or less important.
According to the guideline all key protection structures should be monitored at least every three years. The monitoring interval for the monitoring sections is determined by the local Water Managing Authorities individually, for example depending on the dimensions or condition of the structures or the hazard potential on the alluvial fan. A guide value for the main protection units is 3 to 5 years and up to 10 years for the basic protection units.
The result of the self-monitoring is written down in a monitoring report. The monitoring report for key protection structures is more detailed and designed
Self-monitoring of torrent control protection structures in Bavaria
Rainer Höhne, Dipl.-Ing1; Andreas Rimböck, Dr.-Ing.1
RISK GOVERNANCE AND POLICIES (OBJECTIVES, STRATEGIES, COMMUNICATION)
INTERPRAEVENT 2016 – Extended Abstracts | 35
as a kind of check list for the monitoring in the field.
CURRENT STATUS
The whole strategy for self-monitoring was proved in a one year test phase. In the meantime the key protection structures, the monitoring sections and the associated monitoring intervals are almost defined by the Water Management Authorities, so that the regular monitoring program according to the new guideline can start.
Analyzing the data of three Water Management Authorities, which already finished the classifica-
tion, less than 0.5 % of the protection structures are key protection structures, but about 25 % belong to a main protection unit.
REFERENCES
- Österreichisches Normungsinstitut (2008). ONR 24803. Schutzbauwerke der Wildbachverbauung.
Betrieb, Überwachung und Instandhaltung.
- Deutsches Institut für Normung (1985). DIN 19663. Wildbachverbauung. Begriffe, Planung und Bau. Beuth Verlag GmbH Berlin.
Figure 1. Categories of torrent control structures. Basis: Aerial photo & DTM (c) Bayerische Vermessungsverwaltung (2015)
KEYWORDS
protection structures; database of structures; monitoring; maintenance
1 Bavarian Environment Agency, Augsburg, GERMANY, rainer.hoehne@lfu.bayern.de and andreas.rimboeck@lfu.bayern.de
