Estate and commercial landscape irrigation: zones and control.
An estate, a hotel or an office landscape is watered by many zones that run at night, unseen, for years. Before you approve a design, you are deciding how the grounds are split into zones, how the system is controlled and checked, and whether your staff can reach every part of it. This guide sets out what to ask for, with a check that the watering fits into the night.
Written for estate and facility managers.
Zone by sun, planting and use
A zone is a group of sprinklers or drip lines that one valve opens together. An estate follows the same rules as a home garden, on a larger scale. Hunter's design guide draws the lines between zones by sun and by plant type, and never puts rotors or rotating-stream nozzles on the same zone as fixed sprays, because they put water down at very different rates. Hunter's tree brochure adds that trees are watered on zones of their own, apart from lawns and shrubs.
Split by use as well. An events lawn, the planting around a pool, the verges along a road and the beds at the entrance are watered, rested and repaired at different times, so each is easier to manage on zones of its own.
A typical estate ends up with zones like these:
- Open lawns in full sun, on rotors.
- Lawns in the shade of buildings or trees, on their own sprinklers.
- Narrow lawns and verges, on rotating-stream nozzles.
- Shrub beds and hedges, on drip line, split by sun and shade.
- Trees, on bubblers or drip line.
Home garden and lawn irrigation
Sources: Hunter Industries (2019), Residential Sprinkler System Design and Installation Guide (LIT-226), pages 6 and 9; Hunter Industries (2025), Irrigating Trees: best practices brochure (HI-042), pages 2 to 4.
An estate in zones
The drawing shows part of an estate. The lawn in the sun and the lawn in the building's shade are separate zones, and so are the shrub beds and the trees. The four valves sit together in one bed beside the drive, and the controller in the gatehouse opens them one after another.
- Lawn in full sun: a zone of rotors, which throw their water far
- Lawn in the building's shade: a zone of its own, on small sprays
- Shrub beds: a zone of drip line, with water beside each plant
- Trees: a zone of their own, with a bubbler at each trunk
- Valve boxes for all four zones, together in one bed beside the drive, where staff can reach them
- Controller in the gatehouse: opens one zone at a time, at night
Matched coverage
Matched coverage means two things. First, every sprinkler throws its water as far as the next one, which Hunter calls head-to-head coverage, so no strip between them stays dry. Second, every sprinkler on a zone puts down water at the same rate, which Hunter calls matched precipitation. A sprinkler watering a quarter circle at the corner of a lawn gives a quarter of the flow of one watering a full circle in the middle: Hunter's example uses 5, 10 and 20 litres a minute for a quarter, a half and a full circle.
On large lawns, rotors keep the system simple: Hunter notes that where a large-area rotor can be used, the job usually needs less pipe, fewer valves and a smaller controller.
| Area | What usually waters it | What to check |
|---|---|---|
| Open lawn, 8 by 8 metres or more | Gear-driven rotors such as the PGP Ultra or I-20, throwing 4.9 to 14 metres | Each head reaches the next; rotors have zones of their own |
| Small lawn or verge | Pop-up bodies with MP Rotator nozzles, throwing 2.5 to 10.7 metres across Hunter's range, 9.1 with the nozzles in our store | One nozzle family across the zone, so the rate matches |
| Shrub beds and hedges | Drip line along the rows | A filter and a pressure regulator after the valve, and a flushing point at the line ends |
| Trees | Bubblers or drip line | Zones of their own, and a plan to widen the watering as the tree grows |
Hunter PGP Ultra rotorHunter I-20 rotorHunter MP Rotator nozzleHunter Pro-Spray pop-up bodyHunter HDL-PC driplineHunter PCN bubbler nozzle, which fits a Pro-Spray body
Sources: Hunter Industries (2019), Residential Sprinkler System Design and Installation Guide (LIT-226), pages 6, 16 and 26; Hunter Industries, PGP Ultra rotor: specifications; Hunter Industries, I-20 rotor: specifications; Hunter Industries, Standard MP Rotator nozzle: specifications; Hunter Industries (2015), Drip Irrigation Design and Installation Guide (LIT-496), page 11; Hunter Industries (2026), Product Catalogue Vol. 41, EMEA metric edition, page 169; Hunter Industries (2025), Irrigating Trees: best practices brochure (HI-042), pages 2 to 4.
Central or smart control
One controller for every zone on the site makes the watering easy to see and to change. Count the zones before choosing it, then allow for more: Hunter's example plans ask for at least two spare stations on each controller, and its design guide runs at least two spare wires to every group of valves, because they are much harder to add once the planting has grown in.
A smart controller is connected to the internet. Hunter's Hydrawise controllers, such as the HCC with 8 to 54 stations, let a manager change programs and see the controller's status from a phone or a computer without a site visit, adjust the watering to past, current and forecast weather, and keep the system's layout on file with the controller. Check that there is a reliable Wi-Fi connection where the controller will hang.
A flow meter tells the controller how much water each zone uses. Hunter's HC Flow Meter on a Hydrawise controller sends alerts for high, low or unscheduled flow, so a leak or a fault shows up quickly, before the planting suffers.
A smaller site can run on a standard controller such as the X-Core, with a Mini-Clik rain sensor. Valves far from any power point can run from a battery controller such as the NODE, which sits in the valve box. It works only with DC-latching solenoids, which only the one-zone NODE-100 includes, so each valve on a NODE-200 or NODE-400 needs one in place of its standard 24 V solenoid.
Hunter X-Core controllerHunter NODE battery controllerHunter Mini-Clik rain sensor
Sources: Hunter Industries, Example Hunter legend (architectural style): controller notes; Hunter Industries (2019), Residential Sprinkler System Design and Installation Guide (LIT-226), page 17; Hunter Industries, Hydrawise software cut sheet, pages 1 and 2; Hunter Industries, HC Flow Meter: features; Hunter Industries, NODE battery controller: features and specifications; Hunter Industries (2026), Product Catalogue Vol. 41, EMEA metric edition, pages 87 and 133.
Night watering windows
Hunter's design guide advises watering early in the morning, when there is least wind and the pressure is highest, and less water is lost to evaporation. It advises against early evening, because a lawn left wet all night is more likely to get diseases. On an estate, the hours before dawn also keep the sprinklers off guests, cars and paths. That gives the site a fixed window, and every zone's run has to fit inside it.
Drip laid under the surface is the exception: Hunter's drip guide notes that it can run at any hour, even while the grounds are in use, so it does not need a place in the window.
Sources: Hunter Industries (2019), Residential Sprinkler System Design and Installation Guide (LIT-226), page 26; Hunter Industries (2015), Drip Irrigation Design and Installation Guide (LIT-496), page 5.
Valve boxes staff can reach
Every valve sits in a valve box with a lid, never buried straight in the soil. Hunter's design guide groups the valves for each area together in a spot that is easy to reach, close to the area they water but where whoever opens a valve by hand will not be sprayed. It leaves at least 15 cm between valves for repairs, and a capped spare outlet of 8 cm or more for later additions.
On an estate, put each group in a bed beside a path or a drive, where staff can reach it without crossing wet lawn, and mark each lid or keep a list so that the zone number on the controller, on the drawing and on the box all match. Drip zones also need small boxes at the far ends of their lines, where they are flushed, and at the high points, where air is let out.
Sources: Hunter Industries (2019), Residential Sprinkler System Design and Installation Guide (LIT-226), pages 10, 16 and 17; Hunter Industries, Example Hunter legend (architectural style): drip and box notes.
Sleeves under paving
A sleeve is a larger pipe laid under a road, a path or a terrace before it is paved, so that irrigation pipes and wires can be pulled through it later. Hunter's example plans put sleeves under all paving and hard surfaces, twice the diameter of the pipe or bundle of wires they carry, and running past the paving edge. Ask for every sleeve to be shown on the drawings and laid before the paving goes down: once it is down, a missing sleeve means cutting the paving open.
Source: Hunter Industries, Example Hunter legend (architectural style): sleeving note.
As-built drawings and a maintenance plan
When the work is finished, the site should receive a record of what was actually built, not only what was designed. Hunter's drip guide asks for the pressure to be measured and written down at each zone valve and at each flushing point when the system is first inspected, and for the controller schedule of every valve to be noted, so that later faults can be traced against them. Hydrawise can store the layout with the controller, so the position of pipes and valve boxes is not forgotten.
Ask for these at handover:
- A drawing of the system as built: the main, the valves, the wires, the sleeves, the sprinklers and the drip lines, with the zone numbers.
- The controller program: run times, days and start times for every zone.
- The pressures measured at handover, zone by zone.
- The makers' manuals and specification sheets for each part.
- A list of spare parts to keep, such as nozzles, sprinkler bodies and drip fittings.
- A maintenance plan that says who checks what, and how often.
- Training for the staff who will run the system.
Irrigation maintenance through the seasonComparing irrigation quotes
Sources: Hunter Industries (2015), Drip Irrigation Design and Installation Guide (LIT-496), page 24; Hunter Industries, Hydrawise software cut sheet, page 1.
When to ask for a site-specific design
Hunter recommends a professional irrigation designer for large residential and commercial projects. Before asking for a design, gather what the designer will need:
- A site plan or survey, with the buildings, roads, paths and paving.
- The planting plan, or photos of each area: lawns, beds, hedges and trees.
- Where the water comes from, with a pressure reading or the pump's details.
- Whether the same supply also gives drinking water: if it does, the design needs a backflow preventer of the type the water supplier requires.
- Where power is available for a controller and a pump.
- The hours when watering is allowed.
- Who will look after the system, and how often.
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