Landscape and utility coordination

Why is landscape-utility coordination hard?

Civil and landscape are designed by different consultants on different drawings using different conventions, but they share the same site. Trees grow into utility easements, irrigation lines cross sleeve locations, light poles land on top of storm pipe, and root barriers conflict with underdrain. Coordination of landscape and underground utilities is one of the most under-managed areas of site design.

Which site utilities should landscape coordinate against?

Landscape should coordinate against water, sewer, storm, gas, power, comms, and irrigation laterals.

• Domestic water service and meter
• Sanitary sewer service and lateral
• Storm sewer mains and inlets
• Storm detention and underdrains
• Site fire service and hydrants
• Gas service
• Electrical primary, secondary, and site lighting feeders
• Telecom and fiber
• Irrigation main and sub-mains
• Site drainage swales and area drains

What tree-versus-utility rules of thumb should you use?

Keep mature tree canopies and roots out of utility easements and away from water and sewer mains.

• Mature tree root spread typically equals canopy spread; some species exceed it
• Maintain minimum 10' horizontal separation between trees and most utilities
• Maintain 20' from sanitary lateral cleanouts and meter pits to allow access
• Avoid planting deciduous trees over leach fields or drainage swales
• Specify root barriers near hardscape, foundations, and shallow utilities
• Coordinate planting depth with utility depth to avoid puncturing during installation
• Trees with invasive root systems (poplars, willows) require larger separations

What should irrigation coordination catch?

Irrigation coordination should keep mains and laterals clear of storm pipe, lighting conduit, and tree pits.

• Irrigation main routed clear of other utilities with code-required separation
• Backflow preventer location accessible and on the warm side of any wall
• Sleeves under hardscape sized for future maintenance
• Drip vs. spray zones matched to planting type
• Controller location accessible and on a separately metered or sub-metered circuit if required
• Rain/soil moisture sensor compliant with local water-efficiency codes
• Pressure regulation and master valve included where local code requires

How should site lighting coordinate with landscape?

Overlay the landscape plan on the civil and lighting plans before either set goes out for permit.

• Pole foundations clear of underground utilities
• Conduit routes coordinated with planting, irrigation, and other site utilities
• Pole locations sized for required maintenance access
• Photocell or astronomical timing as required by local energy code
• Light trespass and uplight limits met per local code
• Coordinated with site security and CCTV camera locations

What field conflicts show up between landscape and utilities?

The usual field conflicts are trees in easements, irrigation crossing utilities, and lights in tree canopies.

• Tree root ball intersects buried electrical or telecom conduit
• Light pole foundation hits storm drain
• Irrigation main crosses gas service without required separation
• Backflow preventer in proposed planter area
• Sleeves under hardscape too small for irrigation contractor's pipe
• Root barrier specified but no detail showing how it integrates with sleeves
• Planting depth conflicts with shallow utility depth

What should each designer provide for site coordination?

Civil should provide invert and easement data; landscape should provide tree, irrigation, and lighting layouts.

• Civil: utility plan with depths, inverts, and easements
• Landscape: planting plan with mature canopy and root spread indicated for trees
• Landscape: irrigation plan with main routing, zones, and equipment locations
• Electrical: site lighting plan with pole foundation locations and conduit routing
• Architect: hardscape plan with sleeve locations and sizes
• Geotech: soil conditions affecting planting and pole foundations