Consider the set up of your school's gutters, especially the downspouts, when placing the rain barrels and drip irrigation.
Teaching students to use rain barrels to store water and drip irrigation to use the water that has been collected gives them life-long lessons in sustainability and self-reliance. Rain barrels store rain water that would fall to the ground through the gutter system; a drip irrigation system involves hose lines that have been punctured with emitters to allow water to drip out into the soil holding nearby plants. These two projects can be combined into one for students of all ages.
Concepts
Some simple math will have to be discussed in a rain barrel and drip irrigation system. An educator may want the students to figure out how many rain barrels they will need for the project. The amount of rain barrels that should be used depends not only on the budget, but also the amount of rain water that can be collected from the roof of the school. The formula to calculate the rain water capacity is the square footage of the roof times the annual rainfall in inches times .623 gallons per square inch of rainfall. A cubic inch of water equals .623 gallons. The answer to this equation will give the amount of rainwater in gallons the conditions provide. Then the students should convert this number into rain barrels. Most rain barrels hold 50 to 60 gallons. So, the students should divide the answer in gallons by 55 to find the number of rain barrels they will need for maximum water storage.
Supplies
The supplies the students can use are going to be limited by the budget. There are some essentials that a rain barrel and drip irrigation system cannot do without, including the barrels themselves, automatic-siphoning hoses, some PVC adapters, a stop valve and a drip line. All of these items, including the drip lines and fitting pieces, can be bought at local hardware stores. The project will also require some tools, including a caulking gun and a power drill with a 1-inch bit to make a bung in the rain barrels in order to attach them to each other and to attach the drip line. Depending on the age of the students, the teacher can use this tool.
Putting It All Together
The rain barrels should be positioned as close to one of the downspouts of the gutter system as possible. Methods for attaching the first rain barrel to the downspout will depend on the types of downspouts and rain barrels the students have. The simplest method is to place the end of the downspout in the barrel. One hole should be drilled near the top of the barrel. This is to attach the automatic syphoning hose. The hose is shoved through the hole as far down into the barrel as possible. The next intermediate rain barrel should have two holes drilled near but not at the top. The hose attached to the first barrel is also stuck into this next intermediate barrel. The students should continue in this manner to the last barrel. On the final barrel, drill a hole near the bottom. Insert a PVC bung into this lower hole and caulk it, then screw in a female PVC adapter. Screw the stop valve onto this adapter. Screw the drip irrigation hose onto the stop valve. Lay the drip irrigation hose in the soil near the garden beds.
Improvements
One of the first issues the students may face in utilizing their rain barrel and drip irrigation system is poor water pressure. The water pressure in the drip irrigation line determines how far down the line the water will come out. Poor water pressure may prevent all of the drip line from being used. A water pump, placed between the stop valve and drip line, can regulate the water pressure. Another method is to raise the height of the rain barrels in relation to the drip line. The higher the rain barrels are, the more pressure the water running through the drip line will have. Another potential issue in the collection system is particulate, such as leaves and grit, getting into the rain barrels and creating obstructions. The students can place a filter, such as a microfiber sheet, between the downspout and first rain barrel. Another solution is to simply check for clogs and clean them out.
Tags: rain barrels, drip irrigation, drip line, drip irrigation system, irrigation system, rain barrel, stop valve