An irrigation map is a schematic representation detailing the precise location of all buried components within a landscape watering system, including main lines, lateral pipes, valves, and sprinkler heads. Creating an accurate map provides a foundation for efficient troubleshooting, planning future landscape changes, and analyzing water conservation potential. This documentation ensures that maintenance and repair work can be performed quickly and without unnecessary excavation.
Preliminary Steps and Necessary Tools
Begin the mapping process by gathering the necessary investigative tools. A simple collection of materials, including a measuring tape, brightly colored marking flags, a clipboard with graph paper, and a pen, will facilitate documentation. A small hand shovel or trowel may also be useful for exposing buried valve boxes or sprinkler heads covered by turf or soil debris.
The first physical step involves locating the system’s fixed, above-ground components. Identify the main water shutoff valve, which controls the water supply, often located near the main utility connection point. If the system includes a backflow prevention device, note its location immediately as the starting point of the mainline.
Next, find the irrigation controller or timer, which dictates the scheduling and sequence of the watering process. Understanding how to manually activate the individual zones through this controller is a prerequisite for the tracing phase. Reviewing the controller’s settings may also reveal the numerical order and the assigned name for each zone.
Prior to any probing or light excavation, consider the location of other underground utilities, such as gas or electrical lines. Marking these lines, if known, adds a layer of safety and prevents accidental damage during system exploration. This preparatory step ensures that the physical tracing can proceed safely.
Identifying and Tracing Control Zones
With the main components identified, the next step is the sequential activation of each control zone to determine its extent. Use the controller to turn on the first zone, allowing water to pressurize the lateral lines and activate the designated sprinkler heads. If the controller is not functional or accessible, the solenoid on the valve itself can often be manually opened by turning a small bleed screw or lever.
As the water flows, systematically place a marking flag next to every sprinkler head or drip emitter operating in that specific zone. This visual marking represents the area serviced by a single control valve. Once all active heads are marked, turn off the water for that zone to prepare for documentation.
The next objective is to locate the solenoid valve box that governs the set of flagged heads. Since the valve box is the source of water for the lateral lines, it is usually located centrally or along the assumed pipe path. A common technique involves listening near the flagged area immediately after activating the zone; the sound of water rushing into the valve helps pinpoint its location.
Once the valve box is found, record its distance and direction from a fixed reference point, such as a corner of the house or a driveway edge. This measurement is useful for accurately plotting the valve’s position on the final map. Assign the valve a corresponding number that matches the zone number used on the controller for consistent documentation.
After locating the valve, visually estimate the routing of the buried lateral pipes that connect the valve to the marked sprinkler heads. In most residential installations, these pipes follow the shortest practical route, often in relatively straight lines or parallel to hardscape features like patios and walkways. Use the flags as endpoints to sketch the assumed path of the pipes connecting them back to the control valve.
While the zone is active, document the specific type of emission device being used, such as fixed spray heads, rotating stream rotors, or low-volume drip emitters. Note the approximate radius of water coverage for each head (typically 8 to 15 feet for sprays and 15 to 30 feet for rotors). This detail provides insight into the water application rate and system design uniformity.
Repeat this process of activation, marking, locating the valve, estimating the piping, and documenting the head types for every zone. Thoroughness ensures that no components are overlooked and that the final schematic accurately reflects the underground infrastructure.
Creating the System Diagram
The final stage involves translating the field notes and measurements into a clear, scaled system diagram. Begin by obtaining a base map, such as a property survey, a hand-drawn sketch of the yard, or an aerial photograph printout. Using graph paper simplifies maintaining a consistent scale throughout the drawing.
Establish a clear scale for the map (e.g., one square equaling five or ten feet), and include a north arrow to indicate the property’s orientation. This standardization ensures that anyone using the map can accurately gauge distances and directions for future repairs or modifications.
Next, create a legend of symbols to represent the various system components graphically. Standard symbols include a small square for control valves, a solid circle for spray heads, and a triangle for rotor heads; consistency makes the map immediately readable. Transfer the locations of the fixed components—the main shutoff, the backflow device, and the controller—marking them with their respective symbols.
Carefully draw the main supply line, which carries pressurized water to the valve boxes, typically represented by a thicker or differently colored line. Then, draw the lateral lines connecting the control valves to their designated sprinkler heads, utilizing the estimated pipe routing from the field tracing. These lines should be drawn thinner than the main line to distinguish their function.
Each control zone must be distinctly labeled on the map, ideally by drawing a boundary around the group of heads it services and numbering it according to the controller station. Next to the valve symbol, indicate the total number of sprinkler heads or emitters operating on that zone. This documentation transforms the field data into a functional maintenance and design tool.