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Valuing Nature
Samuel Vionnet
Sustainability Expert and Founder
+41 (0)76 372 90 27

I support organisations to integrate the value of natural and social capital into decision making, by providing innovative methodologies, data and expertise.

780% return on investment

For every US dollar invested by Novartis in each of the four carbon-sink projects, an average of USD 7.8 worth of societal value is created thanks to climate change mitigation, ecosystem services,...

How sustainable is hydroelectricity?

The Las Cruces hydroelectric project in Mexico might lead to a negative outcome for the Mexican if built. A natural and social capital accounting method has been used to assess the project's impact,...

There is no sustainability without a balance sheet

Measuring social and natural capital only makes sense when we consider balance sheet. So far, very few organizations have managed to do this. We only see P&L published. But P&L is like GPD, it only...

Jobs at all costs

The private sector is exploring new ways to measure its societal impact, moving beyond traditional economic indicators. We developed an innovative model based on social determinant of health studies....

Achieving net positive impact using the SDGs

If not already done, you will have to use SDGs for defining your net positive impact. But how to measure it? I discuss four steps to support you in this difficult task: your theory of change, your...

Honey is worth more than you think

The Association mellifera is developing a high impact social project around honey bees. Valuing Nature sponsored the creation of one bee colony and calculated the societal value created by the...

Solving half the world’s problems

This article explores the role of Natural Capital within the SDGs and addresses in particular the connexions that exist between SDGs targets. It provide as well some statistics on the maturity of a...

The Sustainable Development Goals and the Mont Blanc

An innovative analysis of the SDG’s targets is unlocking barriers and triggering efficient actions to reach these goals by 2030. By understanding that these targets are inter-connected and that...

The wider benefit of water recycling in a water scarce region

ENGIE, a global energy company, used a water valuation approach to assess the benefits of a water recycling project with the help of Valuing Nature. It showed that the overall benefit generated per...

Water scarcity is not a problem… Undervalued water is

This article summarizes the outcome of a session held at the World Water Week 2015, managed by Valuing Nature, which explored the benefits and limitations of the use of water valuation metrics and...

And now what? The future of Natural Capital Accounting

This article presents the results of a survey, of executives working for private companies and consultancies, on the trends and future challenges of the Natural Capital Accounting approach.

Valuing Water – The Basics

The basic concepts of water valuation as an ecosystem service are presented in this article. Water valuation can fulfil the need for a Natural Capital Accounting method for the private sector. This...

Why is Investment in Watershed Services the future of conservation?

Successful conservation projects have mostly targeted low opportunity cost areas in remote locations until now. Conservation has now entered a new phase by competing with humans needs. Investment in...

The Opportunity Cost of Biodiversity Loss in the Swiss Plateau

Measures to maintain the biodiversity on the Swiss plateau would generate 136 millions CHF of benefit for the society. It is urgent that we realize that the sharp decline in biodiversity in...

Global Land Use Dataset

Data is critical to assess the reliance of companies on natural capital. A new model is available to fill this data gap with a global coverage of land use related externalities.

The Value of Rain

A study showed how to link water footprint and ecosystem services valuation to identify the value of rain and freshwater in Santa Cruz (Bolivia) region. This study was done in partnership with Forest...

Natural Capital Accounting - An Introduction

Recognizing the benefits we obtain from nature is key to ensuring long term profit while creating shared value. This article presents shorty the interest for the methodology, illustrated by a case...

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Valuing Nature
Samuel Vionnet
Switzerland - Guatemala
CH: +41 76 372 90 27
GT: +502 4490-5633‬

Valuing Nature is member of


How sustainable is hydroelectricity?

The Las Cruces hydroelectric project in Mexico might lead to a negative outcome for the Mexican if built. A natural and social capital accounting method has been used to assess the project's impact, which can support stakeholders engagement and decision making for this project, but also more widely showcase the potential of such methodology to drive a sustainable development.

The San Pedro river is one of the last free flowing river of Mexico located in the state of Najarit, in the North West of Mexico City along the Pacific coast. It connects a mountainous region upstream to an agriculture fertile plain before ending its course within one of the biggest wetlands in Mexico, the Marismas Nationales, along the Pacific coast. The landscape is sublim.

Marismas Nationales Image

Within its plan to expand electricity production in Mexico, to answer to an increasing demand but also to fullfil its commitment to the Paris agreement, the Mexican government (through its electricity company) is studying the construction of a hydroelectric dam on the San Pedro river. This dam would produce 750MWh of electricity each year and cost 639 million USD to build only. The electricity produced would avoid 305'000 tonnes of CO2-eq according to the government.

For many years, and still now for many persons, hydroelectricity is a renewable energy that is critical to support a sustainable transition of our society. However, more and more researchers, NGOs and other organizations are starting to realize the negative effects that dams can have for our society and the ecosystems. The dam built will have three direct major effects:

  1. Flood a reservoir equivalent to 5'493ha (7'700 soccer fields).
  2. Affect the hydrology of the San Pedro river downstream, by reducing the wet season flow and leading to a reduced flooded area including both agriculture and wetlands surfaces.
  3. Reduce greatly the sediment transportation downstream by the river by trapping it in the reservoir, leading to changes in the wetlands dynamics and generating coastal erosion.

We used natural and social capital accounting methods, derived from the Social and Natural Capital Protocols as well as the Social Return On Investment method to assess the costs and benefits of the construction of the Las Cruces dam. Benefits are mostly linked to jobs created and electricity generated.

Although most of the impacts are negative, ranging from coastal erosion, loss of agricultural productivity through reduced flooding, greenhouse gases emissions (GHGs) from the reservoir and materials used for the construction of the dam, GHGs released from the reduction in size of the mangroves and wetlands areas linked to the reduced flooding during the wet season, impact on fisheries productivity, displaced population and flooding of scared sites, loss of ecosystem services provivded by the ecosystem flooded by the reservoir and so on.

Overall, our model showed that the net societal cost of the Las Cruces dam is negative, leading to a negative cost over 25 years of 931 million USD. Looking at the financial results and accounting for the recent fact that the Mexican electricity market has been liberalized, reducing market prices, the project would create an accumulated loss of 279 million USD. All those costs would need to be covered by the Mexicans in a way or another.

Even the estimation done by the national electricity company on the GHGs avoided is largely over-estimated, as it did not accounted for the land use change (wetlands and mangroves) and direct emissions from the reservoir, leading to GHGs avoided of only 17% of the expected amount. The electricity produced by the dam would generate as much CO2 as an efficient natural gas power plant.

Using the same methodology to account for the societal impact of a project or activity, we compared the Las Cruces dam to other sources of electricity, as illustrated in the figure below. We integrated an average scenario (most likely events) and a minimum and maximum scenarios, accounting for the worse and best cases (in orange on the graph and in yellow the average electricity mix of Mexico). The Las Cruces dam societal cost is far above other renewables such as wind or other more sustainable types of hydroelectricity. However, it is still better than more polluting sources of electricity such as coal and oil. Although the maximum scenario shows that he could be as bad as those latter potentially.

Comparison electricity sources impact valuation

It is clearly a project with an unfavourable outcome, leading to a net negative societal cost. This methodology allows to bring light to a complex project with many dynamic interactions with communities, the economy and the nature. This type of analysis is crucial to support stakeholders engagement and support decision making around similar projects.

The report published will hopefully contribute to the local debates on the project in Mexico, but also showcase the potential of natural and social capital accounting as a tool to drive a sustainable development.

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