AAU Sustainable engineering: Research on ecosystem valuation

You recently read about the role the environment and ecosystems play in our economy and society. This included an example of the New York City drinking water supply and the measures NYC (and other cities in similar situations) is taking to invest in an ecosystem service rather than a more expensive infrastructure alternative.
Do some independent research and find a different example of how an ecosystem service is valued. You need at least one source but if the source is reliable (academic journal, industry report, newspaper article, etc.) you do not need multiple sources.
Submit a written assignment (no more than 1 page) that answers the following questions:

Explain what the ecosystem is, what service it provides to the community, and how that service contributes to human development.
Is there a quantitative value assigned to the service (i.e. $)? How?

Is there an estimate of how much an alternative (infrastructure) system would cost?

In what ways does can this ecosystem valuation be improved?