Principle 5

Principle 5: Improve Irrigation Efficiency And Stormwater Management.

Water-impervious surfaces such as streets, parking lots, sidewalks, and roofs are non-point sources of pollutants and shed valuable stormwater during storm events. Whenever hard surfaces are redesigned, EWU should consider reducing its footprint to allow stormwater to soak into the ground or utilizing pervious materials such as pavers or porous concrete. Managing runoff from storms and snowmelt is an essential task – use pervious pavements where possible to minimize non-point source pollution of waterways while also increasing groundwater recharge and reducing stress on existing stormwater infrastructure.

Objectives and Strategies

  • The irrigation control system will be converted to a central control system with ET water management to irrigate the campus more efficiently.
  • The campus irrigation system will be evaluated by maintenance staff to identify weak areas that can be costeffectively modified or replaced to reduce water use.
  • Irrigation systems will be designed with new landscapes incorporating drought tolerant and low water use species to reduce water use by implementing more efficient irrigation systems.
  • An irrigation as-built database and mapping will be developed to monitor and maintain irrigation systems more efficiently.

  • The use of potable water for irrigation will be reduced.
  • The draft Wastewater Reuse plan will be reviewed and evaluated for implementation to utilize wastewater pumped from buildings and discharged to storm sewers.
  • Existing wastewater systems at Patterson Hall and Hargreaves Hall will be assessed and modified to provide data regarding reuse water quantities and improve efficiency.
  • Rainwater harvesting and reuse in landscape irrigation will be implemented where practical.

  • Reduce hardscape areas where possible and integrate water, vegetation, and soil systems to protect water quality, reduce pollution, prevent flooding, and treat stormwater at the source.
  • Expand on-site infiltration by implementing low-impact development (LID) strategies such as bio-infiltration soils, rain gardens, and other best management practices to increase water quality and decrease the quantity of stormwater runoff.
  • Stormwater runoff from parking lots and other impervious surfaces will be captured for infiltration in landscape areas.
  • Existing stormwater facilities will be renovated to incorporate native and adapted plantings to reflect local habitat types and to increase natural functions.

Irrigation Efficiency and Conservation

The two primary keys to improving campus irrigation efficiency are control of irrigation timing and efficient water application. EWU has begun the implementation of a central control system to control the application and timing of irrigation more efficiently. Utilizing a wide range of environmental inputs that include evapotranspiration, types of plantings, soils, and slopes, a central control system will significantly improve the efficiency of the campus irrigation system.

Additionally, the irrigation water service should be renovated to consolidate points of connection and supply to the irrigation mainline to reduce the number of backflow prevention devices that require maintenance and annual inspection. The consolidation would include flow control and management to fully understand the amount of water utilized for irrigation on campus and create measurable data to track improvements and water savings. Implementing the central control system campus-wide is the most effective way to reduce water use in the landscape.

Water Re-Use

Several campus buildings have installed sump pumps to remove water from basements year-round. A Wastewater Reuse Plan was previously developed that incorporated new and existing tanks to receive the wastewater for storage and reuse in irrigation. Currently, two buildings have demonstration systems, Patterson Hall and Hargreaves Hall.

These two systems should be evaluated and upgraded to provide measurable data on the amount of water reused and track system efficiency. These two systems are included in the Wastewater Reuse Plan.

Rainwater harvesting and reuse in landscape irrigation should be implemented by capturing roof runoff and holding it in tanks (water reuse) or cisterns for later use, possibly in garden areas.


Effective stormwater management protects water quality, minimizes erosion, and recharges groundwater. Rather than directing runoff from rooftops and pavement into pipes and street gutters, new development and redevelopment should best use topography, soils, and vegetation to slow down, filter, and eliminate runoff.

Stormwater runoff from impervious surfaces should be captured in stormwater swales or rainwater gardens where possible. Bio-swales intercept runoff through check dams and are planted with native species that can tolerate a range of wet to dry conditions. They slow contaminated runoff, allow the vegetation to filter out impurities, provide carbon sinks, and create new habitats for wildlife.