Yard & Landscape Drainage in Menifee

Yard & Landscape Drainage questions from Menifee customers

Why does my Menifee backyard stay wet for days after a storm?

A geotechnical study for a Menifee residential site measured infiltration of roughly 0.6 to 0.9 inches per hour at five feet and 0.0 inches per hour at ten feet. Ground that stops accepting water at depth holds it near the surface. Standing water then becomes a question of where the water can be led, not of loosening the top few inches of soil.

Is a Quail Valley yard a different problem from a yard in a newer Menifee subdivision?

The Santa Ana Regional Water Quality Control Board found roughly 37 percent of Quail Valley households surveyed had sewage discharges to the ground surface during the 2004 and 2005 storms, and tied it to high groundwater, poor soils and shallow impermeable strata. Those parcels also sit high: USGS samples in Quail Valley run near 1,474 to 1,589 feet against about 1,424 feet in Sun City. Slope flow has to be intercepted, not just collected.

Where is yard water supposed to end up on a Menifee lot?

Menifee's code states that each lot shall be graded so stormwater will drain from the backyard through the side yard and front yard directly to the abutting street where feasible. That makes the side yard the working corridor on most lots in the city. When a patio slab, raised planter or side-gate hardscape interrupts it, the backyard becomes the collection point by default.

Can I just send yard water into a planted infiltration area?

Newer Menifee projects do use engineered infiltration: a recent tentative tract's hydrology report routes lot runoff through catch basins into a bioretention and detention basin. That basin is sized by an engineer against a Hydrologic Soil Group D rating for the site. A backyard version copied without that sizing tends to hold water rather than release it.

What does landscape drainage repair involve on a Menifee lot?

Finding where the water enters and where it can leave, then choosing what carries it. In Menifee the first step is placing the lot: a newer tract lot usually has an interrupted drainage route, an older lot may never have had one, and a lot on the western high ground also receives water moving through the slope above it. The Menifee guide on this site works through the three cases and what the City's code requires.

Why does a short Menifee storm flood a yard?

Because of intensity, not annual rain. NOAA's Atlas 14 gives the Menifee location a 100-year 24-hour depth of 5.41 inches, of which 1.58 inches can fall in a single hour. Roofs, patios and compacted ground shed that burst faster than most yards can take it in, which is reasoning from those figures, so a yard with nowhere for the water to go floods in storms that look small on an annual total.