Written by Jackie Calla '17E November 2016

A feature of the new Greenway dorms is rainwater harvesting on the roofs. Harvesting of rainwater in Greenway simply involves the collection of water that has fallen and is collected from the roof and subsequently stored for later use. 


The capturing and storing of rainwater goes back thousands of years to when humans first started to farm and needed to find new ways to irrigate crops. In hotter climates, capturing the occasional rainfall often meant the difference between life and death for some communities. The practice of rainwater harvesting decreased substantially as urbanization increased but, now we are again returning to this ancient and key method of greener living.  

Rainwater Harvesting Techniques

The collection of rainwater from the roofs of our Greenway dorms is a fairly simple process. All that is needed to capture water is to direct the flow of rainwater from roof gutters to a rainwater storage tank. This way, water can be collected and used for various needs. Amherst College’s Greenway dorms also feature stormwater wetlands protection system. The main purpose of constructed stormwater wetlands is to maximize the removal of pollutants from stormwater runoff through settling and filtering by vegetation. As an added bonus, they stormwater wetland protection system at Greenway provides aesthetic features to the community. 

Rainwater Collection

Benefits in Rainwater Harvesting

The main usage of harvested rainwater in our Greenway dorms is for toilet use, feeding 75 toilets throughout the building. This saves an incredible amount of water, that would otherwise be supplied by nearby dams or aquifers. The ability to capture water directly allows us to significantly reduce our dependence on water storage dams. This is one of the main benefits from rainwater harvesting.

It is imperative that we recognize we have a very limited supply of water available and it is very costly and timely to produce water through dams. Harvesting rainwater helps us cut back on our major sources of water systems in urban areas. In urban areas, communities are rapidly contributing to the disappearance of lakes and other natural hydrologic courses, making rainwater harvesting an even more attractive alternative to not only capture water but to also help restore bodies of water. We can also significantly decrease our environmental impact by incorporating more natural infrastructure, such as rainwater harvesting, instead of mechanical infrastructure.

Additionally, the overall cost of installation operation is much lesser than that of conventional purifying and pumping systems. Rainwater harvesting uses simple technologies that are relatively inexpensive and easy to maintain. The water that is collected can be used in many substantial ways even without purification and can serve as an excellent back-up source of water for emergencies. 

Rainwater Harvest System

Rainwater can be used for many purposes! The main usage of harvested water at Greenway is for flushing toilets but homeowners and other communities also use rainwater harvesting for drinking purposes, showers, washing clothes, watering gardens, and irrigation since rainwater is free from many chemicals found in groundwater. Water is our most precious natural resource and something that most of us take for granted. Our Greenway dorms are making great steps towards achieving Amherst College’s goal of significantly decreasing its environmental impact and are setting a precedent of green building practices we can incorporate in our own homes and communities.