Applications of Life-Cycle Cost Analysis in Water and Wastewater Projects: Lessons from European Experience - Governing the Nexus: Water, Soil and Waste Resources Considering Global Change - page 136

Fig. 9 Curve of present value course for alternative sewerage systems of a rural area in Germany.
Source SMUL ( 2004 , p. 38), amended

means). The period under consideration is oriented on the service life of the water
engineering facilities (e.g. 50 15 years for small sewage

plants). In Fig. 9 , the results of a dynamic comparative cost calculation for different
system alternatives of wastewater treatment in a rural community are shown.
Alternative 1 is the most cost-effective over the considered period of 100 years
while alternative 2 is economically unfavourable. Considering alternatives 3 and 4,
in the medium-term, decentralized plants (separate sewerage systems) are superior
to semi-central plants/ones (collective sewerage systems) due to lower investment
costs. This leads to a trade-off associated with higher operational costs, and with a
period under consideration of more than 30 years, the advantage changes from
decentralized to semi-central plants. From the cost perspective, alternative 1 is
favourable, but further considerations such as the autonomy of communities may
lead to preference for other options. In this context, LCC can provide objective
reasons for such discussions.

80 years for canals, 10

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4.3 Cost of Settlement Development

Infrastructure costs and life cycle considerations are also important and relevant
aspects from the viewpoint of settlement planning. The question raised in this
context is, how expensive will settlements be in the future. The

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cost of sprawl is