Highland, CA Environmental Rules: Erosion Control (2026)

Highland Municipal Code § 16.64.070 controls human-induced accelerated erosion in the City of Highland, in areas within or adjacent to mountains and hillsides. No person can cause or allow a condition on any site that is causing or is likely to cause accelerated erosion, as determined by the building official. After notice from the city engineer or building official, the owner must take appropriate measures within a reasonable period set by the building official, and can be required to obtain approval of a soil erosion and sediment control plan or permit. Either official can order an operation stopped during inclement weather if erosion is not adequately controlled.

No land clearing or grading, other than exempted activity, can occur unless it complies with an approved soil erosion and sediment control plan or permit. The plan must be submitted and approved before building permits, soil erosion and sediment control permits, grading permits or any other permit issue where the building official expects erosion. The building official sets the application requirements, including licensing or certification for those preparing submittals. Applications with no land disturbance, such as change of use permits with no expansion of land-disturbing activities and construction within an existing structure, need no plan.

Runoff from development activities must be controlled with measures adequate for a 10-year storm. Where soils have a permeability rate of more than two inches per hour, runoff above predevelopment levels is retained on site. Where soils drain at two inches per hour or less, runoff is detained or dispersed so the rate does not exceed predevelopment levels. No earth, organic or construction material can be placed where it can be carried into a stream, lake, marsh, slough, lagoon, or body of water, and work near watercourses needs a buffer zone that confines visible siltation within 25 percent of the buffer zone nearest the work.

Land clearing is kept to a minimum. Disturbed surfaces get temporary planting or mulching and permanent planting, and topsoil on slopes less than 20 percent is stockpiled and reapplied. Protection must be installed before calling for final grading approval and at all times between October 15th and April 15th. Vegetation removal in that window cannot precede grading or construction by more than 15 days. During the rainy season, the building official authorizes contiguous clearing of more than one acre in a one-year period, and major grading of more than 100 cubic yards, only when the project complies. Erosion control measures must be in place at the end of each day's work. Permittees notify the building official at least 24 hours before starting authorized work, and filing a development permit application grants the City permission to enter the permit area.