French Drain Installation in Winchester

French Drain Installation questions from Winchester customers

How deep can a French drain go on a Winchester lot before it meets groundwater?

Groundwater sets the limit. USGS measured depth to water across the Winchester subbasin at 6 to 72 feet in 1994-95, generally less than 11 feet through most of the central part. A 2021 geotechnical investigation at Willard Street and Highway 79 estimated high groundwater at ten feet below grade. On the valley floor a gravity trench has to work within that.

My Winchester parcel is on septic — how does that limit where a French drain can run?

Riverside County's onsite wastewater program requires five feet of undisturbed soil between groundwater and the bottom of a leach trench, and ten feet beneath a seepage pit. Its setback provisions also hold septic tanks, leach lines, leach beds and seepage pits fifteen feet from a drainage course. A French drain that creates a new drainage course, on ground where water was measured near eleven feet, uses both allowances at once.

Where can a French drain legally discharge if the frontage is on Highway 79?

Not into the highway without state approval. The county's area plan puts Winchester's core at the intersection of Winchester Road, State Route 79, and Simpson Road, and Caltrans defines an encroachment as any structure or object in, under or over state highway right of way, with authority under Streets and Highways Code sections 660 to 734. Its permit guide lists drainage facilities among frontage improvements requiring a permit.

Which agency's stormwater rules apply to a French drain outlet in Winchester?

The Santa Ana Regional Water Quality Control Board's. Winchester is unincorporated, so the County of Riverside is the co-permittee, with Riverside County Flood Control and Water Conservation District as principal permittee, under Order R8-2010-0033, adopted January 29, 2010; the regional board notes a replacement permit under consideration. The order covers the Upper Santa Ana River, Middle Santa Ana River and San Jacinto hydrologic units, and Salt Creek is a San Jacinto River tributary.

What should I have ready before asking about a French drain in Winchester?

Four things make the first conversation useful: where the water collects and how long it stays, whether the ground is soft or only the surface is wet, whether the lot is on septic, and what the frontage is, since a street with a curb, a dirt road and a State Route 79 frontage each lead to a different outlet. Photos taken during or just after a rain help. The Winchester drainage guide on this site sets out how county rules, flat ground and shallow groundwater shape the choice.

On a flat Winchester lot, does a French drain come before regrading?

Usually the surface comes first. USGS describes about 12 of the Winchester subbasin's 20 square miles as relatively level valley floor, and on level ground standing water is more often a matter of getting surface water to an outlet than of intercepting water from above. A drain buried under a surface that still pitches toward the house does not correct that pitch. That is reasoning from the terrain, not a finding about any one lot, and a site visit settles it.