Yard & Landscape Drainage in Winchester

Yard & Landscape Drainage questions from Winchester customers

Where does runoff from a Winchester yard actually end up?

In Canyon Lake. The county's Harvest Valley/Winchester Area Plan places the community immediately south of Double Butte and north of Salt Creek, and describes Salt Creek as separating the planning area into northern and southern halves. The Santa Ana board's revised nutrient TMDL technical report identifies Salt Creek as draining to the East Bay of Canyon Lake, with 735 of the watershed's 782 square miles reaching that reservoir.

Why do nutrients from a Winchester yard matter more here than in other towns?

Because the receiving water is already impaired. Lake Elsinore was listed in 1994 and Canyon Lake in 1998 for low dissolved oxygen and excess algal growth, and the revised TMDLs set numeric targets for total phosphorus and total nitrogen. Urban runoff is carried as its own wasteload allocation category, which is why yard drainage in this watershed is treated as a water quality question, not only a nuisance one.

Is there a flood control plan for Salt Creek where it runs past Winchester?

Yes. Riverside County Flood Control and Water Conservation District filed a Negative Declaration for the Salt Creek Master Drainage Plan on September 13, 1996, described as covering proposed channel improvements to Salt Creek, with the location given as Hemet/Winchester and cross streets Winchester Road and Olive Avenue. A master drainage plan is the district's instrument for a community's current and future drainage needs.

How much of the Winchester area is flat enough that yard water simply sits?

Most of it. The USGS study of the Winchester subbasin describes a 20-square-mile basin containing about 12 square miles of relatively level valley floor, and the county area plan characterizes the wider planning area as flat valley floors, gently rolling foothills, abrupt buttes and hillsides. On level ground standing water is usually an outlet problem rather than a slope problem.

What does landscape drainage repair involve on a Winchester lot?

It starts with finding where the water enters and where it can leave, then choosing what carries it: a regraded surface where the fall can be restored, a catch basin or channel drain where it cannot, and a piped run to an outlet either way. In Winchester the outlet is the hard part, because the area is unincorporated county ground, much of it flat, and groundwater has been measured close to the surface. The Winchester guide on this site walks through how those conditions rule some fixes in and others out.

Can a dry well handle yard drainage in Winchester?

Often not as the main answer. A 2021 geotechnical report at Willard Street and State Highway 79 measured percolation of 30 and 60 minutes per inch, or 0.2 and 0.1 inch per hour, and estimated high groundwater at ten feet below the surface. The County's low impact development handbook asks for ten feet between an infiltration facility and the historic high groundwater mark. That is one site, so a test on the lot decides it, but slow soil with shallow groundwater is the combination that makes a dry well fill and stay full.