It's a real privilege to be here with you all. This has been a great couple of days. So at Plant With Purpose, we combat environmental degradation, climate change, conditions of poverty, and broken relationships by healing the land, people, and relationships. And we do this through a three-pronged theory of change and program, which includes economic, environmental, and spiritual objectives, to which we believe the whole is greater than the sum of the parts.
And we apply this model at a sub watershed level, working directly with just a critical mass of the population, which would be between 40 and 70%, in an effort to transform the entire watershed. Because when it comes to environmental restoration, change in farming behavior, and the healing of broken relationships, our hypothesis is that you don't actually have to work with every single person in the watershed in order for the vast majority to experience a benefit.
And so this is an example from the Dominican Republic. This is the Upper Ozama watershed. And the colors represent the topography of the watershed. And the red squares represent households that are clustered around savings groups. And so this is a model of about 40% saturation of the total population.
Now because we have a multi-dimensional model, finding the best place to work can be a challenge. And so what we've done is used GIS to conduct what we call opportunity mapping. And what we're looking for is the intersection of poverty, sloping land, and deforestation. And so…
We've combined those three data sets to identify where our model might have the greatest impact. And you can see the individual data sets on the left and the combination of those three on the right. And the areas of the darkest purple color are the areas where the three of those factors are most severe.
Now because we work at a sub watershed level, the next step for us is a hydrologic delineation of the sub watersheds that are in the areas of highest opportunity for us. And so we'll start looking at factors like area and total population, which you can see in the table on the right, as well as maybe other relevant data like proximity to environmentally protected areas, such as national parks, which are shown in green.
So by knowing how big the watersheds are and how many people are in them, we can actually start to estimate how many savings groups we're gonna need in order to achieve that 40 to 70% participation target.
So that was a little bit about how we're using mapping technology to identify where we work, and now I'll talk about how we actually measure our impact.
We did our first impact evaluation in 2008, and the reason we started doing impact evaluation was to inform and improve our program. And of course, this data has helped us to build trust and confidence with donors. But still, our North Star, when it comes to indicators and methodology, is our theory of change. Because if we correlate each data point that we choose to collect with the theory of change, of course we're going to be more likely to be able to correlate the results that we see, whether favorable or unfavorable or neutral, with the actual program activities. And after each evaluation, we develop an improvement action plan, make appropriate adjustments, and repeat that cycle.
So we're using a triangulation approach, and what we're looking for is a convergence of evidence. We're using household surveys, geospatial analysis with remote sensing, and participatory workshops with community members. So I'll start with an example of a geospatial analysis we did recently.
So part of our model includes the protecting of existing forests and the planting of trees. And participants in these watersheds are planting hundreds of thousands of trees in every watershed every year. And so this analysis is looking at the percent tree cover data from the MODIS platform. And we looked at the annual change in tree cover from 2015 to 2021.
So this analysis included a neighboring comparison watershed, the overall country average, and of course the treatment watershed where we started working in 2015.
And you can see pretty clearly in the graph that in the comparison watershed and the country average, there was a one-half percent annual increase in tree cover over that time period, and in the treatment there's about a three-and-a-half percent annual increase. Now, of course, this is an exciting result for us, and we're looking forward to tracking it into the future, but it's not conclusive and we don't stop there.
So next, I'll talk about a participatory watershed analysis.
So in this exercise, community members use a printed map of the watershed and they're asked to identify areas where trees are either increasing or decreasing, and areas where water is increasing or decreasing. And you can see they've drawn with a sharpie on this map. And in this particular exercise, they identified five areas where trees were increasing, one area where trees were decreasing, five areas where water flow was increasing, and three areas where water flow was decreasing.
So after the locations have been identified on the map, the participants are asked to discuss the causes of these trends. And for us, having community members speak directly about the causes of what they're seeing is really meaningful. A, because it helps us to understand attribution, what's attributed to our work or what isn't. But also it tells us about other significant factors and influences in that watershed that we probably want to be aware of.
And so this kind of analysis gives us an understanding of the changes and the causes of changes that geospatial analysis and household surveys don't give us.
So of course, the third and key data set for us comes from household surveys.
So we start by collecting complete household lists from each watershed that we're studying. And we use those to generate a random representative sample based on a 95% confidence level and a 7.5% confidence interval. And this slide shows one of the complete household lists from a watershed and the yellow highlights were households that were randomly selected for the survey.
Now of course, because it's from the entire watershed, it's gonna include direct participants and non-participants because we're not working with every single person in the watersheds. But here's an example of the kind of change we're seeing. So this slide shows the application of regenerative techniques per household. And we're comparing a treatment watershed where we have been working for two years and a control watershed where we're not yet working.
You can see on the left at baseline, there was nearly no technique application. And after two years, there's an average of 3.1 in the treatment watershed, which is great. But it's not surprising because our program includes an agroecological curriculum that promotes these regenerative techniques.
But what's really exciting about it is we're only working with 40 to 70% of that population and these results are at a watershed level. And so in this next graph, I've separated that 3.1 in the treatment watershed into non-participants and participants in the treatment watershed. So you can see non-participants in turquoise and participants in green. And so non-participants have significantly increased their technique application.
And there appears to be an influence not just on direct participants, but also non-participants in the treatment watersheds. And so here's another example showing an increase in savings reserves, which are measured in months. And you can see same thing at baseline. There's an average of about one half of a month in both cases. And after two years, there's an average of 3.2 months in the treatment watershed. When you separate into participants and non-participants.
Again, you can see a significant increase amongst non-participants in the treatment watershed.
So by addressing the vicious cycle of environmental degradation and poverty and turning it into a virtuous cycle of holistic transformation, we're seeing the socioeconomic and environmental conditions improving in the watersheds where we work for thousands of farmers like you see in this picture from Tanzania. We believe and we have observed that by healing relationships, restoring the environment, and providing an opportunity for people to grow out of poverty. Holistic transformation can take place across the entire watershed.