Texting Water Tanks: Remote Monitoring Applications

We constantly remotely communicate with each other. Texting, Twitter, Facebook, and so many more channels allow us to send information everywhere. This human communication is second nature to most of us at this point. What if this communication could be extended to send us information not just from our friends but from homes or bee hives or water tanks? It turns out it can! This remote communication and monitoring is what I have been working on in the Harvey Mudd Global Clinic project for the past semester.

As we discover new technology and new ways to collect data, we are more and more able to monitor things from a distance. This is known as remote monitoring, and a lot of new research is happening in this exciting field. Remote monitoring is a common theme in bee lab. My project on mapping flower densities, the smart hive project, and bee visitation tracking all fall under this category. Collecting data in this way can be a powerful tool for biologists by providing larger quantities of accurate data for analysis and reducing the need for time consuming field work. In a similar vein I have been working with the global clinic program on another remote monitoring project. During the 2015-16 academic year the Global Clinic team worked with a non-profit called RainCatcher to develop a remote monitoring system for rainwater harvesting systems.

The team in front of a RainCatcher tank

RainCatcher is a nonprofit that works in Kenya, Uganda, and the Navajo Nation to install and maintain rainwater harvesting systems. These systems help to provide easy access to clean water in areas that lack it, and provide drought relief by storing water for later use in agriculture. RainCatcher prides itself on its commitment to the communities it works in and it maintains its tanks for 10 years after installation. This maintenance means that while rainwater harvesting systems from other organizations often fall into disrepair, RainCatcher ensures that their systems continue functioning. However, this maintenance is often extremely expensive and time consuming for RainCatcher staff. Every quarter a representative from RainCatcher visits each site and checks that the systems are still functioning. With 120 sites and still growing, this presents a huge time commitment and challenge for RainCatcher. That is where our global clinic team comes in. RainCatcher asked us to design and implement a monitoring system that would allow them to remotely check that their systems are functioning. We hope that by using our system they can not only avoid unnecessary visits to sites that are working perfectly, but also reduce the time to repair a broken system and thus provide a more consistent supply of clean water.

The system had to meet several important constraints. RainCatcher strives to bring clean water to as many people as possible. In this mission cost has been a large limiting factor. Installing and maintaining each tank site is expensive, and as the organization expands these expenses grow. With that in mind we worked to keep our system under $35. We hope that this low cost will allows RainCatcher to install monitoring devices on all of their tanks, present and future, without too large of a financial burden. The device also needed to be easy to install and maintain, durable enough to last outside in varying weather conditions for 10 years. RainCatcher’s tanks last for around 10 years, so we wanted our device to have a similar lifetime. The device also needed to provide its own power, because access to reliable electricity isn’t possible at many of the sites where RainCatcher works.

Our final device is housed inside a PVC pipe to protect it from the weather

In order to accomplish this we designed a system that measures the water level in the tank and checks for the presence of water in the rain gutter and outside, stores that data, and then transmits the data via a cell network. The data is then stored and visualized in an online system that we built in with help from the team at EchoMobile. While we designed our system to monitor a rainwater harvesting system, the basic functionalities of collecting, storing, transmitting, and analyzing data could be extended to many remote monitoring applications simply by changing the sensor used. Almost the same system could, for example, be used to transmit the data collected by the smart hive project directly to us in the lab. Ecologists face many of the same constraints that we had. For a system to be practical for fieldwork it needs to be robust and self-powering. Inexpensive systems that can be left in remote areas for months and continuously collect and transmit data would allow ecologists to collect much more data than traditional methods.

Each device was attached to the rain gutter leading into the tank. The tubing protects the sensor wires and is dropped down into the tank through a hole drilled in the gutter. 

After finishing the design and prototyping stages of the project we travelled to Kenya in early June to test our design in the field. Over the course of 4 days in the Kisumu region we were able to install working monitoring devices at 5 different sites. All of this data is being logged to a web platform, meaning that we are able to see that all of our devices are still working! It is very exciting for us to be able to see, all the way from California, that RainCatcher’s systems in Kenya are still collecting rain water. It is our hope that RainCatcher will eventually install this system on all of their tank sites and that the data collected will help to improve clean water access for their communities. We are also hopeful that RainCatcher will be an example to other organizations, encouraging the adoption of remote monitoring to ensure that the time and money invested in solving global problems is not being wasted.

The trip wasn't all work! The team enjoyed a visit to the equator. 

Personally, I am glad I had the opportunity to learn about remote monitoring, and I look forward to bringing those skills with me to future projects. Who knows, maybe bee lab will soon have texting equipped bee hives!

Further Reading:

1. Remote Sensing free online journal
2. RainCatcher Learn more about RainCatcher's work in Kenya and Uganda