Aliso Viejo Municipal Code Art. XIII Erosion Control

A. The faces of cut and fill slopes and project sites shall be prepared and maintained to control against erosion in accordance with this section. Where cut slopes are not subject to erosion due to the erosion-resistant character of the materials, such protection may be omitted upon approval by the building official.

B. Where necessary, temporary and/or permanent erosion control devices such as desilting basins, check dams, riprap or other devices or methods, as approved by the building official, shall be employed to control erosion and provide safety during the rainy season from October 1st to April 30th.

C. No grading work in excess of 200 cubic yards will be allowed between October 1st and April 30th on any single grading site under permit unless an erosion control system has been approved or waived by the building official.

D. Paved streets, sidewalks, and other improvements shall be maintained in a neat and clean condition free of loose soil, construction debris and trash. Street sweeping or other equally effective means shall be used on a regular basis to prevent storm flows from carrying sediment and debris outside the project boundaries. Watering shall not be used to clean streets except for fine material (not otherwise removed by sweeping or other mechanical means) unless the water is vacuumed from the street and disposed of in a manner acceptable to the building official.

E. Unless otherwise approved by the building official, the owner shall be required to retain a civil engineer who will be responsible for the design of all erosion and sediment control improvements and initial approval of the installation of permanent and semi-permanent erosion control devices during each rainy season until the work authorized by the grading permit is given final approval. The owner shall retain the civil engineer to periodically review the field condition and modify, as needed, the design of the permanent and semi-permanent erosion and sediment control devices during the rainy season. Installation and maintenance of all erosion and sediment control devices shall be the responsibility of the owner.

F. Desilting facilities shall be provided at drainage outlets from the graded site.

G. Desilting basins shall be designed to provide a minimum desilting capacity equal to the current city standards.

H. Desilting basins shall be constructed around the perimeter of projects whenever feasible.

I. Desilting basins constructed of compacted earth shall be compacted to a relative compaction of 90 percent of maximum density. A soil engineering report, prepared by the soil engineer, which includes the type of field testing performed, location and results of testing shall be submitted to the building official for approval upon completion of the desilting basins.

J. Equipment and workers for emergency work shall be made available at all times during the rainy season. Necessary materials shall be available on-site and stockpiled at convenient locations to facilitate rapid construction of temporary devices when rain is imminent.

K. Erosion protection shall consist of effective planting of all slopes in excess of five feet high unless otherwise approved by the building official. Slopes exceeding 15 feet high may require an adequate irrigation system, as determined by the building official.

Protection for the slopes shall be installed as soon as practicable which may be prior to rough grade approval. Effective planting shall be installed, fully germinated and effectively cover the required slopes prior to final approval unless otherwise approved by the building official.

L. The erosion control provisions shall take into account drainage patterns during the current and future phases of grading throughout the rainy season.

M. All removable protective devices shown shall be in place at the end of each working day when the five-day rain probability forecast exceeds 40 percent.

N. Graded areas around the tract perimeter must drain away from the face of slopes at the conclusion of each working day.

O. In addition to the requirements specified above, the permittee shall perform all work in accordance with the water quality requirements. The building official may include additional requirements in the grading permit or any other permit issued by the building official, outside the rainy season defined in subsection (B) of this section, that the building official deems necessary to assure compliance with water quality requirements including but not limited to measures affecting construction outside the rainy season defined in subsection (B) of this section and/or grading permits.

P. Any violation of an applicable federal or state-issued stormwater permit, or failure to conform to the water quality requirements prepared pursuant to such a permit or pursuant to this chapter or to AVMC 7.35.010 et seq., or failure to comply with stormwater-related provisions of a county-issued grading permit or of a grading plan prepared to secure such a permit, is also a violation of this chapter. [Ord. 2010-126 § 1 (Exh. A); Ord. 2003-044 § 2 (7-1-835)].

Erosion control plans prepared in accordance with Subarticle 13 of the grading manual shall be submitted to the building official for approval by September 15th each year for projects under grading permit. The erosion control plan may be waived for grading projects on single residential lot projects providing that an erosion control system, meeting the approval of the building official, has been installed, placed, planted or constructed before October 15th. [Ord. 2010-126 § 1 (Exh. A); Ord. 2003-044 § 2 (7-1-836)].

A. After each rainstorm, silt and debris shall be removed from all erosion and sediment control devices and the basins pumped dry as deemed necessary by the building official. The pumped material shall be deposited in a manner acceptable to the building official.

B. After each rainstorm, the performance of the erosion control system shall be evaluated and revised and repaired as necessary.

C. Devices shall not be moved or modified without the approval of the building official.

D. The contractor shall be responsible and shall take necessary precautions to prevent public trespass onto areas where impounded water creates a hazardous condition.

E. The contractor and permittee or project owner shall be responsible for continual maintenance of the devices during the rainy season. In the event of failure or refusal by the contractor, permittee or project owner to properly maintain the devices, the building official may cause emergency maintenance work to be done to protect adjacent private and public property and environmental resources. The cost shall be charged to the owner and shall include an initial mobilization cost plus the cost of doing the work as contained in Article VI of this chapter.

F. In the event the building official must cause emergency maintenance work to be done, the building official may revoke the grading permit in writing. The grading permit shall not be renewed until an erosion control system and/or other systems necessary to comply with water quality requirements approved by the building official are installed and a fee of one-half the amount required for the original grading permit is paid by the owner. The building official may waive installation of an erosion control system after April 30th.

G. If any grading subject to AVMC 13.08.060 has commenced on private property without a valid grading permit, the property owner may be required to prepare and implement an erosion control plan as well as other plans required under the water quality requirements which have been approved by the building official. In the event of failure by the property owner to install an approved erosion control system and/or other systems necessary to comply with water quality requirements, the building official may cause emergency work to be done to protect adjacent private and public property. The procedures of AVMC 13.08.120 need not apply for emergency erosion control work between October 1st and April 30th and emergency work necessary to protect environmental resources. The cost shall be charged to the owner in accordance with subsection (E) of this section. [Ord. 2010-126 § 1 (Exh. A); Ord. 2003-044 § 2 (7-1-837)].