1. Assessing Environmental and Social Impacts of Infrastructure:
Rainwater-fed Reservoirs in Honduras
Dan Evans
Bureau Environmental Officer, Global Development Lab
I’m Dan Evans, the Bureau Environmental Officer for the Global Development Lab.
As Teresa mentioned, the case study that I want to discuss requires assessing environmental impacts of a project that the Lab recently funded to construct rainwater-fed reservoirs in Honduras.

2. Project Goals
Construct 10 rainwater-fed reservoirs (6,000-35,000 m3) in a drought-stricken region of Southern Honduras
Let me start with a project overview. Our goals are:
First, to construct 10 rainwater-fed reservoirs – with a water storage capacity between 6,000 and 35,000 cubic meters -- in a drought-stricken region of Southern Honduras; so these reservoirs cover about as much area as a few football fields
Dan Evans

3. Project Goals
Construct 10 rainwater-fed reservoirs (6,000-35,000 m3) in a drought-stricken region of Southern Honduras
Provide drip irrigation systems to 10 smallholder farming communities, benefitting more than 200 people
Next, after the reservoirs are constructed, the project will provide drip irrigation systems to 10 smallholder farming communities benefitting more than 200 people
(Here you can see (1) some of the drip irrigation hardware staged at the side of a field and (2) one drip line irrigating a watermelon plant, which some local farmers grow as a cash crop)
Dan Evans

4. Project Goals
Construct 10 rainwater-fed reservoirs (6,000-35,000 m3) in a drought-stricken region of Southern Honduras
Provide drip irrigation systems to 10 smallholder farming communities, benefitting more than 200 people
Allow farmers to
Increase productivity
Extend the growing season
Become more resilient to climate-induced droughts
Our ultimate goal is to allow farmers to increase productivity, extend the growing season, and become more resilient to climate-induced droughts
Dan Evans

5. Reservoir Design Dan Evans
Here are a few illustrations that show how the reservoirs are designed.
As you can see, each reservoir sits at a low point in a natural water catchment and is designed to capture and store rainwater runoff, which can be used to irrigate targeted crops in each community.
Dan Evans

6. Reservoir Sites Before Construction
These pictures show what the reservoir sites looked like before construction started.
The picture in the middle shows stakes marking where the dam will go across this ravine
Here you can see the dam will cut across a rocky streambed
A lot of the area is slashed and burned by local farmers to clear land for agriculture
And, as this picture shows, a lot of the reservoir sites have been heavily grazed by cattle
Dan Evans

7. Reservoir Locations Dan Evans
Reservoir sites
Here’s a map that shows more precisely where the reservoir sites are located. As I’ve already mentioned, the project site is in the Southern part of Honduras, within these different watersheds. This is the Gulf of Fonseca, and there is a Ramsar wetland here.
Dan Evans

8. Ecoregions in the Project Area
Reservoir sites
Reservoir sites
This map shows the primary ecoregions in the project area, comprised of a few different kinds of forest, with mangroves along the coast
Dan Evans

9. Primary Livelihoods in the Project Area
Reservoir sites
Reservoir sites
Here are the primary livelihoods in the project area.
Along the coast, some people have jobs fishing or working in shrimp farms in the coastal estuaries. Farther away from the coast, people are more likely to be subsistence farmers or to work on farms growing cash crops.
Overall, poverty in the area is quite high
~80% of Population in Poverty
Dan Evans

10. Scaling it Up: The Government of Honduras Intends to Build ~100 Similar Reservoirs in the Region
What are some key environmental and social impacts that we should consider?
Damaging critical habitat for endangered species
Restricting natural water flows to wetlands in the region
Landslides and erosion on hillsides where reservoirs are constructed
Cattle contaminating reservoirs with feces
Competition for water with shrimp farmers on the coast
Reservoirs failing due to poor construction, threatening communities downstream
Reservoirs attracting disease-carrying mosquitos
Unsustainable hunting of animals that are attracted to reservoirs
All of the above
All but A
All but C&F
All but D
Our team identified several potential environmental and social impacts that the project will likely have, and we designed mitigation measures to address them.
But rather than tell you what those are and discuss them, I want to emphasize that this situation is rapidly changing on the ground because the Government of Honduras intends to build 100’s of similar reservoirs in the region. This could have significant environmental and social impacts throughout the region. So I’d like to spend the rest of my time brainstorming with you about what those are and how we can mitigate for them.
Dan Evans

11. Scaling it Up: The Government of Honduras Intends to Build ~100 Similar Reservoirs in the Region
What mitigation measures should we should consider to address these potential impacts?
Compile information and / or conduct studies to assess species abundance & distribution
Avoid locating reservoirs in critical habitat for endangered species
Compile information and / or conduct studies to assess regional hydrology
Design reservoirs with spillways to ensure downstream water flows
Use construction design checklists to ensure quality construction
Use fences to keep cattle out of reservoirs
Stock reservoirs with fish that eat mosquito larvae
Training / capacity building to ensure that hunting is sustainable
All of the above
All but A&C
All but E
All but G
Dan Evans

12. Potential Environmental and Social Impacts
Environmental Impacts:
Dams will reduce water flows downstream of the reservoirs
Livestock might contaminate water in the reservoirs
People might overhunt wildlife that are attracted to the reservoirs
Social Impacts:
Reservoirs might become breeding sites for disease-carrying mosquitos
Access to water could create conflicts within beneficiary groups
Diversion and withdrawal of water could create conflicts with other water users
This last slide is just extra: It gives a short list of the key environmental and social impacts that we identified and for which we designed mitigation measure in our Environmental Assessment
DM Evans