§ 30.55.100. Grading Methodology and Practice.

A.

In addition to the other provisions of the Del Mar Municipal Code, projects located within the Coastal Bluff Overlay Zone shall be subject to the following provisions:

1.

All projects involving grading shall be subject to the submittal of an erosion and sedimentation control plan. Said plan shall ensure that all drainage from the impervious surfaces of the site will be collected and appropriately discharged in a manner which will prevent drainage and/or erosion related damage to the coastal bluff or any other properties or improvements in the vicinity. In addition, the plan shall include the provision of drainage facilities to convey all drainage away from any coastal bluff face and, where available, into existing developed storm drain systems capable of handling all anticipated drainage flows associated with the proposed project. Where an existing storm drain system is not available, the plan shall provide that drainage will be conveyed to a clearly defined, legal natural drainage course which can be shown to have adequate capacity to handle all required drainage flows without adverse impact to coastal bluffs. All designs and plans for drainage improvements shall be prepared by a licensed civil engineer and shall be subject to the review and approval of the City Engineer.

2.

All projects requiring a Conditional Use Permit and a Coastal Development Permit pursuant to the provisions of this Chapter shall be subject to the submittal of a detailed landscape plan. Said plan shall ensure that native and other drought-tolerant plant species will be utilized in a manner that will minimize irrigation requirements and reduce the potential of slide hazards due to over watering of the bluffs. Said plan will ensure that no new irrigation systems will be installed within 40 feet of the edge of the coastal bluff top and that any existing irrigation systems located within said 40 foot bluff top setback will be removed as part of project implementation.

3.

All projects involving grading shall be subject to the submittal of an erosion and sedimentation control plan. Said plan shall ensure that the project will not result in an increase in peak runoff from the site over the greatest discharge expected during a ten-year, six-hour frequency storm. Runoff control shall be accomplished by a variety of measures including, but not limited to, temporary and/or permanent on-site catchment basins, detention basins, siltation traps, energy dissipaters and the installation of landscape material. The required erosion and sedimentation control plan and any proposals to increase flows shall be subject to review and approval of the City Engineer.

4.

All temporary erosion control measures proposed or required pursuant to the provisions of this Section including berms, interceptor ditches, sandbagging, hay bales, filtered inlets, debris basins, silt traps, or other similar measures shall be installed prior to the commencement of grading in the areas for which the erosion control measures are intended.

5.

For projects involving a total of more than 25 cubic yards of cut and/or fill grading, no grading shall occur during the rainy season, identified for purposes of this Chapter as the period from November 15th to March 31st.

6.

In addition to other erosion control measures required pursuant to this Chapter, all graded slopes shall be stabilized prior to the November 15th onset of the rainy season through the provision of vegetative erosion control. Vegetative erosion control may be achieved through measures such as: landscape planting, seeding, mulching, fertilization, and irrigation. The installation of vegetative erosion control shall occur with sufficient time to achieve landscape coverage prior to the November 15th start of the rainy season.

7.

All permits shall be subject to the submittal of a polluted runoff control plan. The required plan shall incorporate the use of structural and non-structural Best Management Practices (BMPs), to the extent necessary, to minimize the discharge of pollutants carried by runoff from urban development into surface water drainage, and to maintain post-development peak runoff rate and average volume at levels similar to pre-development levels. The plan shall include, but not be limited to the following Best Management Practices (BMPs), as applicable: silt traps, catch basins, oil/grit separators, street sweeping and cleaning program, low-maintenance landscape and pesticide management plan, solid waste management and public education program. Post-construction structural BMPs (or suites of BMPs) should be designed to treat, infiltrate or filter storm water runoff from each storm, up to and including the 85 ^th percentile, 24-hour storm event for volume-based BMPs, and/or the 85 ^th percentile, one-hour storm event, with an appropriate safety factor, for flow-based BMPs. The plan shall include a monitoring component to ensure long-term maintenance of BMPs as relevant, and to allow for continued evaluation of the effectiveness of the polluted runoff control plan in meeting the goals of LUP regarding the protection and enhancement of sensitive resources.

(Ord. No. 733)