One of the first questions we ask on any new irrigation project is where the water is coming from. It shapes nearly every decision after it: how the system is designed, what equipment is needed, how many zones can run at once, and what ongoing maintenance looks like. In the greater Bucksport area and across much of rural and semi-rural Maine, that answer is often a private well rather than municipal water, and the difference between the two changes the entire design approach.
At Mainely Irrigation, a Division of Just Grass, Inc., we design and install irrigation systems supplied by both well water and municipal connections throughout the greater Bucksport, Bangor, Downeast, and Midcoast Maine area. This post walks through what actually differs between the two water sources and what to know before installing a system on either one.
The Core Difference: Pressure and Volume Behave Differently
Municipal water systems maintain relatively consistent pressure and can typically supply a high, steady flow rate on demand, because the system is backed by a municipal storage tank or reservoir and a network designed to serve many properties simultaneously. When you open a zone valve on a municipally supplied irrigation system, the pressure and flow available to that zone are generally predictable and don’t fluctuate much based on what else is happening in the house at that moment, aside from minor drops if multiple fixtures run at once.
A private well works differently. Water is drawn from the aquifer by a pump, typically either a submersible pump in the well itself or, less commonly today, a jet pump. The well’s output capacity, measured in gallons per minute, is a fixed characteristic of that specific well and aquifer, and it doesn’t automatically scale up the way a municipal system does. If your well produces 8 gallons per minute, that is the ceiling for continuous flow regardless of how many zones you’d like to run.
This distinction matters enormously for irrigation design. A system designed without accounting for actual well output can end up drawing the well down faster than it recharges, which causes the pump to run dry, trips a low-pressure cutoff switch, or in more serious cases, can damage the pump from running without adequate water around it.
Designing Around Well Capacity
Before designing any well-supplied irrigation system, we test the well’s actual yield, typically by running the pump and measuring flow rate and pressure drop over a sustained period. This tells us the real-world ceiling for what the system can draw without stressing the well.
From that number, zones are sized so that no single zone, or any combination of zones running simultaneously, exceeds the well’s safe output. On a well with limited capacity, this often means more zones with fewer heads each, rather than fewer zones with more heads, so that each zone stays within the flow the well can sustainably provide. It can also mean longer total watering windows, since zones run sequentially rather than in larger simultaneous groups, to stay within the well’s output over the course of a watering cycle.
Homes that use the same well for both domestic water and irrigation need additional consideration. Running a full irrigation cycle at the same time someone is showering or running the dishwasher can create a pressure drop noticeable throughout the house. Many well-supplied irrigation designs include a dedicated pressure tank or a controller schedule set to run during early morning hours specifically to avoid overlapping with peak household water use, in addition to the water-quality and disease-prevention reasons early morning watering is already recommended.
When a Dedicated Well Makes Sense
For properties with an irrigation demand that would strain a single well shared with the house, or for larger properties with significant turf and planting area, installing a dedicated irrigation well separate from the domestic water well is sometimes the right solution. A dedicated well allows the irrigation system to be designed around its own capacity without any risk to household water pressure or supply, and it removes the domestic use variable from the zone-sizing calculation entirely.
This is a bigger upfront investment than working with an existing well, and it requires its own permitting and drilling, but for larger properties or those with well-documented capacity constraints, it often pays for itself in system reliability and reduced maintenance headaches over the life of the system.
What Municipal Water Simplifies, and What It Doesn’t
Municipal water removes the yield-testing and flow-ceiling calculations from the design process, which simplifies zone planning considerably. But municipal water isn’t without its own considerations. Municipal-supplied irrigation systems are billed based on metered usage, so summer water bills can rise noticeably during peak watering months, particularly for larger properties. Some Maine municipalities offer a separate irrigation meter that is billed at a different rate than domestic use, since irrigation water doesn’t return to the sewer system the way indoor water use does, and it’s worth checking with your local water district whether that option is available, since it can meaningfully reduce the cost of running an irrigation system over a season.
Municipal systems also require backflow prevention, which protects the public water supply from potential contamination through the irrigation connection. This is a code requirement in virtually every Maine municipality with a public water system, and it applies whether the property is residential or commercial.
Well-supplied systems still benefit from a backflow preventer in many cases, particularly where the irrigation system could introduce contamination risk back toward a shared domestic supply, but the regulatory requirement is generally less strict than it is for municipal connections, since there’s no public water system at risk. Local code should always be confirmed, since backflow requirements vary by municipality and by whether any chemical injection equipment, such as a fertilizer or pesticide dosing system, is part of the irrigation setup.
Pressure Boosting for Either Water Source
Regardless of whether a property is on well water or municipal supply, some sites simply don’t have enough natural pressure to run an irrigation system effectively, particularly properties at higher elevation relative to the municipal main, or wells with a lower static water level. In these cases, a booster pump can be added to the system to bring pressure up to the level needed for proper head performance.
Booster pumps add a mechanical component and a modest amount of ongoing maintenance to the system, but for a property that would otherwise have inconsistent coverage or heads that don’t pop up fully, the investment is usually worthwhile. We evaluate pressure at the site assessment stage for every new installation, regardless of water source, and recommend a booster pump only when the numbers show it’s actually needed rather than as a default add-on.
What to Ask Before You Install
If you’re planning a new irrigation system and aren’t sure how your water source affects the design, a few questions are worth asking before you get quotes. If you’re on a well, ask what the well’s tested output is and whether that information is available from the original well log or a recent water test. If you’re on municipal water, ask your water district whether a separate irrigation meter is available and what the current rate structure looks like for outdoor water use. In both cases, ask your installer how they determined the number of zones and the run-time schedule for your specific property, since a generic design that doesn’t account for your actual water source capacity is one of the more common causes of underperforming systems we’re called in to diagnose later.
Getting the Design Right From the Start
Water source is one of the most consequential decisions in irrigation design, and it’s determined by your property, not by preference. Getting the zone count, run times, and equipment right for your specific well capacity or municipal connection at the design stage prevents years of pressure complaints, pump strain, or inefficient watering down the road.
Mainely Irrigation begins every new installation with a full site assessment that includes testing your actual water source capacity, whatever it is, before any zones are laid out. If you’re planning a new system or wondering whether your current one is properly matched to your water supply, we’re glad to take a look.
Call Mainely Irrigation at 207-702-9074 or contact us online. We serve residential and commercial properties throughout the greater Bucksport, Maine area. As a Division of Just Grass, Inc., we’re your year-round partner for irrigation installation, service, and seasonal maintenance.