Environmental Engineering Reference
In-Depth Information
4.1 Asset Strategy Planning Towards Sustainable
Infrastructure Networks
As presented in Sect.
1
, large shares of cities and communities in Europe have high
connection rates to water and wastewater systems and infrastructures. The main-
tenance of these facilities is one of the focuses of infrastructure planning in Europe.
Good practices pursue long-term-oriented concepts of maintaining existing struc-
tures. The security of supply and disposal is the main aspect. Further objectives are
the maintaining of the asset value, the reduction of technical and
financial risks, the
perpetuation of future investment and repair costs, and an appropriate development
of water fees. In order to achieve the formulated objectives, long-term development
strategies are simulated and compared to each other (see Fig.
5
).
Beside technical aspects,
financial impacts along the life cycle of the facilities
are considered. Therein, the costs of investment into the maintenance of existing
facilities are as relevant as the costs that occur for the operation of the infrastructural
systems such as inspections and continuous repair measures (see Fig.
6
). Another
important issue in this context is the ever-increasing price for energy.
Major uncertainties exist in particular concerning the evaluation of probabilities
of fall-out of existing sewers and pipes (Kropp and Baur
2005
) (see Fig.
7
). Sewers
and pipes of different construction types have diverging life cycles and ageing
behaviour. The ageing behaviour is not linear and differs from usually linearly
Fig. 5 Long-term development of the relative net asset value (Relative net asset value = net asset
value/replacement costs. German Water Association (DWA) regulation requires a relative net asset
value greater than 50 %) of the canal system of alternative capital preservation strategies.
Source
City of D
ΓΌ
sseldorf (
2013
, p. 22), amended
Search WWH ::
Custom Search