Sustainable Projects: How can one create sustainability?

My training village was a tiny dot off a bumpy road leading into the desert. It was so small that there was no need for street names, let alone paved roads. Everything was dusted in a thick layer or fine dirt that never went away. Camels roamed through yards, and thorny tumble weeds blew down the streets. A walk through town took ten minutes, running from the growling dogs and brandishing rocks to scare off those brave enough to charge. The little white stucco buildings lining the roads were dwarfed by the plastic covered greenhouses behind them. When nobody answered from inside the house, one could be sure that the family was busy back in the greenhouse. Every house had at least one greenhouse to call their own. They were long 40 foot wooden frames that were covered in the cold months with plastic sheets. All year long tomatoes, cucumbers, lemons, oranges and apricots flourished in the warmth. Families connected their main gas lines to smaller pipes that fueled small stoves in the greenhouses. Children carted buckets and buckets of water from the wells to dump on the rows so carefully dug out months before. When everything was barren, brown and desolate outside, entering one of the greenhouses felt like stepping into a jungle--hot, steaming, green and lush. I never saw another village with a similar abundance of greenhouses. I asked around and found out that they had been a UNICEF project completed five years before I arrived. I witnessed the daily devotional routine practiced by every family in my village--water, weed, pick, prune. The growing produce demanded so continual manual labor, but the pay-off in the end, selling it all at market, was the motivation. For a tiny village with few jobs or opportunities, each family was able to support themselves with the help of the UNICEF project. I could see dedication and determination reserved specifically for the greenhouses. They were cared for, respected, and well used. More importantly, they had lifted the entire village up on the socioeconomic ladder--they had created sustainable economic opportunities for generations.
Just up the road, in the courtyard at the local school sat another UNICEF project. Most students tried not to use the bathroom at school, but waited until they got home. This was for good reason. One could smell the stench 50 feet away, and tried to stay up wind whenever possible. This bathroom was not the UNICEF project. Obviously they had seen the toilet situation at this village school, and had built a new bathroom to improve sanitation. Near the old toilets was a small building with containing a boys side and a girls side with locking stalls, flushable toilets, sinks and screened windows. Maybe at some point there was plumbing, but by the time I arrived, the desert sand had begun to take over the bathroom, and every hole was filled with dirt. The sinks were lizard homes, and the toilet paper holders were broken. Maybe, at some point, the door was unlocked. The sturdy metal door had a brand new lock, and only the school director had the key. "It's locked because it is new and we don't want to ruin it," he explained. So the children continued to hold it until they went home, and we learned that the teachers used the neighbor's outhouse behind the gymnasium, next to her cow. "She doesn't mind", we were told. This was my first encounter with a complete failure of a project in Turkmenistan. UNICEF had good intentions, but unlike the greenhouse project, this one had failed to be sustainable.
In my village I was faced with the challenge of developing a sustainable project in my community. Creating sustainability, for me, is the ultimate goal of the Peace Corps. The Peace Corps commitment is two years precisely for the reason that grass-roots projects are slow going. A sustainable project is not going to be accomplished in a short time, and proper community assessment is a time consuming and meticulous process. Much of community assessment is asking lots of questions to people spanning a diverse population. One must include all demographics to be completely thorough, and gaining the trust of so many people takes time and patience.
Because I spent the most time with my students, I brought up the idea of a project first with them. I had them draw a picture of their community, including everything important to them. This straight forward exercise caused a lot of tension between students because each had their own idea of how the map should look. They all suddenly became very territorial and possessive of their community. When they had each used their marker to