Northern Water stores its raw water in an on-campus pond. This pond and accompanying pump house service most of the campus and about half of the Conservation Gardens. Water-wise landscapes were recently installed as campus development efforts concluded, resulting in the pump replacement last fall to support the additional landscapes. Domestic water is used in the more delicate areas on campus that require drip irrigation.
Bernard said that raw water is best used for overhead irrigation. It contains more sediments than treated water, so it can clog small emitters in drip irrigation systems. For the same reason, supplementing with raw water also requires more frequent equipment maintenance.
Local municipalities Greeley and Superior have also seen success implementing raw water irrigation for their campuses. Due to the need for additional infrastructure, raw water irrigation typically works best on large landscapes, however, there are options for homeowners and small businesses to supplement with raw water. Common methods include rainwater (or snow) capture and greywater (water from sinks, laundry, etc.) recycling.
State and local regulations govern raw water collection and use, so it is important to research current laws before attempting to collect rainwater or recycle greywater for irrigation.