Progress report for FS24-360
Project Information
Being at the lowest end of the value chain, farmers need to be very careful in choosing their investment. Any information that can reduce the uncertainty will help farmers in making investment decisions. Sourcing of irrigation water is one of the crucial decisions made by farmers. Irrigation water availability is a big challenge in urban vegetable farming under high tunnels. The outcomes from the proposed study in terms of a tool kit, and accompanying data on investment plus payback period for rainwater catchment from high tunnel will certainly provide crucial information to high tunnel farmers so that they can make an objective decision and have a peace of mind. This tool kit and payback period information will help a small urban farmer like us, who have a low level of risk tolerance due to limited farm income and resources. Any support from state and federal government to lower the risk of an investment decision will greatly enhance the quality of life of a farmer. Therefore, proposed project and the consequent solution have value for being funded by SSARE grant.
Our hypothesis is that the rainwater catchment from high tunnel will payback the farmer in less than 3 years, and will be profitable for a small urban vegetable farmer. Currently, we have a 16’x100’ high tunnel on one of the three plots of the farm. The high tunnel does not have rainwater catchment. The approach is to install gutters on both sides of the high tunnel, capture the rain water from gutters into rain barrels placed at the end of the tunnels, pump the captured water to drip irrigation in the high tunnel with a solar pump, quantify the amount of water used throughout the year. In parallel, keep record of all the materials, methods and expenses incurred in installing the rainwater catchment. Using two years’ data, estimate how long will it take for the rainwater catchment to payback investment to the farmer. The study will also document the items required and the method of installing the rainwater catchment on high tunnels.
- Install gutters on both sides (lengthwise) of 16’x100’ high tunnel.
- Put one 550 gallon water storage tank on each side of the high tunnel to capture the water from the gutters. If two tanks are used on each side, connect the tanks with a pipe so that overflow from one fills the other tank.
- Connect a water meter to the outlet of the water storage tank supplying water to the drip system. This water meter will record the gallons of water used in watering the high tunnel.
- To increase water pressure in the drip tapes, install a solar pump and connect it to the water storage tank pipe supplying to the drip irrigation. A pressure regulator will also be installed to maintain the water pressure in drip tapes.
- Water the crops inside the high tunnel as needed using the water collected in the storage tanks.
- Estimate the total water used in gallons in the year (May 1st to March 31st) for two years, 2024 and 2025.
- Average the total water used in gallons over two years to calculate average annual gallons of water used.
- Estimate the value of water used from the collection tanks. The 2024 irrigation rate for Town of Cary is $15.05 per 1000 gallons of water used. Therefore, the value of used water can be calculated as: Average annual value of water used= (average annual gallons of water used x $15.05)/1000= $...
- Calculate the total expenses in installing the rainwater catchment on the high tunnel in 2024. Total expense= cost of all materials + installation labor= $...
- Payback period (years)= total expense/average annual value of water used
- As an example, if rainwater catchment over my high tunnel provided me 120,000 gallons of water to irrigate my crops in 2024 and 140,000 gallons in 2025,
- Average annual value of water used= [(120,000+140,000)/2] x $15.05)/1000= $1956.50
- Let’s assume, total expense= $5,000
- Payback period (years)= 5000/1128.75= 2.56
- Details of all materials used and the procedures to install the rainwater catchment will be documented. Based on this detailed documentation, a tool kit report will be prepared for use by other farmers, researchers and academics.
- Actual cost to install the rainwater catchment: $5810
- Total water used from the catchment May 1st 2024 to March 17th 2025: 46858 gallons
- Monetary value of water used: $705
Cooperators
- (Educator and Researcher)
- - Producer
Research
We chose various materials based on the effectiveness and the cost. A contract worker was hired to complete the work. The material list is provided below. Two 550 gallon capacity water tanks were purchased from Tank Depot (tank-depo.com) for a total sum of $2279.70, which was the single largest item cost for the project other than the installation labor. The project is easy to implement/install provided the farmer has time. A project installed by the farmer him/her-self could save a large portion of the project cost ($3700).
Materials:
32’x130 6mil greenhouse plastic $430
200ft vinyl gutters, end caps, support brackets, and connectors $320
45PSI 4.0 GPM Self-priming 115V AC Diaphragm Pump $85
300W Portable Power Station with Foldable 60W Solar Panel $300
3/4" Hose ThreadIPX6 Waterproof, flow meter $20
¾” brass threaded hose fittings, splitter, and teflon tape $75
4” Greenhouse tape to cover wiggle wire channel (2 rolls) $50
Spigot fittings and silicon for each tank $30
¾” Garden hose and splitter to connect tanks $25
¾” hose threaded water filter $15
200 board feet baseboard and hip board lumber $360
3" exterior wood screws $40
1 1/4" exterior wood screws $20
Conduit strap brackets for baseboards x60 $100
5/16” x 2 ½ " bolts and nuts for hip boards x100 $120
T-posts x2 $5
Window screens x 2 $5
Below is result of the first year of the project. A water meter was installed in the water line from the storage tanks to the drip system irrigating the high tunnel. The project expenditure was in line with the budget. The project saved 46858 gallons of water from the town's water distribution system. It also saved the farmer $705 in payment for the water use. Since the water pumping to the drip used a solar pump, there was no energy cost to the farmer. It sustained the high tunnel for irrigation throughout the year. A total of 5 tours were carried out in 2024, with 107 total tour participants. A guest talk is planned for North Carolina State University students (a class of about 25 students) on this topic in April, 2025. The students will be taken to tour the project site after the talk.
- Actual cost to install the rainwater catchment: $5810
- Total water used from the catchment May 1st 2024 to March 17th 2025: 46858 gallons
- Monetary value of water used: $705
Educational & Outreach Activities
Participation Summary:
There will be two CFSA Farm Tours, one in May 2024 and the other in May 2025. In addition to CFSA tours, there are Harvest Fest events on the farm three times a year, once in September, October and November. Farmers and local community participate in these Harvest Fests on Good Hope Farm where Natural & Local LLC will conduct this study. Additionally, a farm-to-fork fund raiser event is also hosted on the farm in October each year. A farm tour is given before the dinner event. All the visitors from these events on the farm will be taken to the rainwater catchment study site and provided with the information. In addition to on-farm events, we also plan to prepare a lecture containing the outcome of the study for undergraduate students in Horticulture Department at NC State University with co-ordination by Dr. Dilip Panthee. At all these events, we will share a summary of the study outcome along with a contact for further details. The study result will be written into a report and presentations will also be prepared. Social media will also be used to publicize the study outcome.
Learning Outcomes
About SARE grants and sustainability of rainwater harvesting
Project Outcomes
Below is result of the first year of the project. The project saved 46858 gallons of water from the town's water distribution system. It also saved the farmer $705 in payment for the water use. Since the water pumping to the drip used a solar pump, there was no energy cost to the farmer. It sustained the high tunnel for irrigation throughout the year. A total of 5 tours were carried out in 2024, with 107 total tour participants. A guest talk is planned for North Carolina State University students (a class of about 25 students) on this topic in April, 2025. The students will be taken to tour the project site after the talk.
- Actual cost to install the rainwater catchment: $5810
- Total water used from the catchment May 1st 2024 to March 17th 2025: 46858 gallons
- Monetary value of water used: $705
The project is still in progress. There has been minimum maintenance to the project. Snow can be an issue in heavy snow areas, since snow can accumulate on the gutters that can make it buckle under weight. There was some snow (estimated total 3 inches) in 2025 at the project site, which caused some areas of the gutter to bend. However, there was no significant damage.