On a recent post on Maryland FarmLINK’s Farm Forum page, a new farmer indicated that he was looking for five acres of pasture to lease. Replies to that post raised a discussion about water supply. Vegetable farmers and meat producers have always needed a secure water supply. During times of drought, all farmers wish that they had a cheap, reliable source of water to irrigate their crops. There are some solutions.
While Maryland typically has more reliable water resources than most of the country, geologists have been warning that the seemingly inexhaustible supply is running out. In general, water sources in Maryland are determined by a property’s location with respect to the fall line (boundary between an upland region and a coastal plain). Water supply above the fall line usually comes from impounded surface water sources (e.g. lakes and rivers with dams). Water supply below the fall line typically comes from aquifers (underground masses of rock, sediment, gravel, or soil that contain water that can be extracted).
Nationwide, there are concerns that aquifers are being drained more rapidly than they can be replenished. In Maryland, most farmland is irrigated on the Eastern Shore. In a dry summer, farmers pump millions of gallons of water from ground water (aquifers). However, on a year round basis, farm irrigation is only about three percent of the total Maryland water usage according to Water for Maryland’s Future: What We Must Do Today. To be feasible for farmers, it must be really affordable.
One way to do that is to look for water where others are not looking. In general, most wells are drilled into confined aquifers (aquifers bounded above and below by confining units of distinctly lower permeability such as clay or rock). These impervious layers prevent pollutants and salt water from penetrating into the aquifers. An unconfined aquifer is is often called a water table. There is no impervious layer between the surface of the soil and the top of the aquifer. As such, unconfined aquifers are replenished directly by rainwater and easily accessible for human use.
Streams and ponds are other potential sources of irrigation water. Joel Salatin (Polyface Farm in Virginia) and Jim and Moie Crawford (New Morning Farm in Pennsylvania) both use streams on the farms to supply water. At the PASA field day on October 16th, Jim Crawford said that he loves a good drought! He can control the amount of water reaching his plants and he can reduce the chances of disease spreading. His stream never has been depleted by a drought. Those interested in building stream dams or ponds should first check with local Soil Conservation Districts and permit offices and check out A Farmer’s Guide to Environmental Permits (page 25).
Shallow dug wells and driven wells are much cheaper to install than artesian wells. Mother Earth News recently published a story about using these methods for homesteads. Along the Patuxent River where I grew up, most houses were supplied by dug wells (some less than 12 feet deep!) and cattle were watered with driven wells. Because of higher nitrogen levels in the groundwater caused by farm fertilization and septic systems, dug wells may no longer be suited for drinking water, but they may be suitable for watering crops, particularly in areas away from septic systems and high nutrient applications.
John Boris, Geologist at the Water Management Administration, says that Maryland law still allows dug and driven wells provided that they are not to be used for drinking purposes. Permits are required if farmers are withdrawing more than 10,000 gallons per day. He can be reached at 410-537-3678 or firstname.lastname@example.org. Marianna Eberle (410-537-3627) is the MDE contact person for farm water appropriation for those withdrawing more than 10,000 gallons per day. See also the Guide mentioned above (page 32).
With increasing droughts and more value-added and vegetable production, farmers need affordable access to water for irrigation and livestock watering. It is time to think outside the box!