Purpose: The purpose of my project is to help an entire neighborhood community conserve water used for general purpose landscape irrigation, prevent costly penalties by staying compliant with city’s water regulations while keeping landscapes lush and green, at a fraction of the cost of current smart sprinkler systems in the market.
Problem statement: California is in a severe drought; eleven out of twelve California’s major water reservoirs are below their historical average. An average Californian household uses 25% of their water for outdoor landscapes. As much as 50% of the water we use for outdoors is wasted on inefficient watering methods. Cities are imposing severe water regulations to help conserve water. Soil moisture sensor (SMSs) and weather-based irrigation controllers (WBICs) are two primary types of smart sprinkler systems available in the market.
They are costly and range from $155-$300 per home and do not always comply with cities water regulation.
Approach: Build a moisture sensor-based smart sprinkler system that can serve an entire community by using a Raspberry PI that integrates real-time weather forecast data to provide only optimum levels of water required in compliance with city water regulations. It will have twittering capabilities to publish information about when and how long to turn on the sprinklers. The residents in the community will subscribe to this information, utilize it to manually adjust their sprinklers to prevent water wasted while landscaping, and also to stay compliant with city-imposed water regulations. It should have the capability to record water saved on a daily basis and email it to all the subscribers on a monthly basis.
Results: Total cost of my prototype is $50. I piloted it with 10 homes, so cost per home is around $5. But since it has the potential to serve an entire community, the cost per home can be a few cents. For example, there are about 37,000 residents in Almaden Valley. If there is an average of 2-4 residents per home there should be 9,250 to 18,500 homes. If I strategically place 10 such prototypes, cost per house would be 5 cents or less. Based on two months data, 83% of the water used for outdoor landscape watering can be saved. Average household use 80 gallons of water for outdoor landscaping on a daily basis. The 10 homes in my pilot had the potential to save roughly 40,000 gallons over two month period or 2000 gallons/month/home. At $0.007/gallon, the savings equate to $168/year/home.
Conclusions: My prototype conserves water used for general purpose landscaping while keeping households compliant with cities water regulations and maintaining the landscapes. For future improvements, I want to make my prototype wireless and calibrate the moisture sensor for temperature variances. In addition, I want to develop an app for subscribers to use and extend its capabilities to other social networks like Facebook etc.