§ 36-72. Site preparation.

(a)

Mandatory requirements.

(1)

Grading.

a.

Temporary air pollution and soil erosion shall be minimized through the retention of natural vegetation and topography until the applicant is prepared to initiate grading and continue immediately with the construction applied for on a continuous process. The period of construction shall be of a duration reasonable to the size and complexity of the development. Top soil shall be retained upon the site and placed over landscaped areas at a depth of not less than six inches. The required development plan shall include an erosion control plan. The methods utilized and the minimum standards for care of the area during construction shall be in conformance with the requirements of the subdivision regulations for the city.

b.

Buildings and improvements shall be located on the site to minimize changes to the existing topography and the loss of existing, mature landscaping. All existing trees eight inches or larger in diameter shall be reflected on the development plan, and where they are proposed to be removed, justifications shall be provided.

c.

Areas of natural vegetation shall be preserved along property lines, including fence rows and drainage ways, and should be incorporated into the site's overall landscape concept. The development plan for the project shall identify "no-grade" zones for this purpose.

(2)

Storm water drainage.

a.

No project shall cause downstream properties, water courses, channels, or conduits to receive storm water runoff from the proposed project at a higher peak flow rate than would result from the same storm event occurring over the site of the proposed project with the land in its natural, undeveloped condition. Where down stream conditions would be overtaxed by runoff from present or planned developments, and where runoff cannot be absorbed upon the site, detention areas shall be created to slow runoff. All storm water storage facilities shall be designed with sufficient capacity to accommodate all runoff caused by the project in excess of the runoff which would have resulted from the site left in its natural, undeveloped state. The storage capacity of all storage facilities shall be sufficient to store 115 percent of the excess flow, in each watershed, which would result from a 25-year storm of 24- hour duration.

b.

Wetlands, which are important to storm water retention, shall be maintained. The elimination of wetland areas upon the site, and the mitigation required for such elimination, shall be governed by the U.S. Army Corps of Engineers.

c.

Storm water entry and discharge points shall be protected to minimize erosion and to avoid relocating a problem to upstream or downstream properties.

d.

Where the subject property is impacted by a surface drainage ditch, creek, river, or other waterway, the banks of the waterway will be stabilized as directed by the city engineer.

(3)

Floodplains. No building or structure, or any portion thereof, shall be constructed within the limits of special flood hazard areas inundated by the 100-year flood, as identified in the applicable flood insurance rate map distributed by the Federal Emergency Management Agency, unless the finished floor elevation of the building or structure is higher than, or is raised by filling to, an elevation at least one foot higher than the 100-year flood elevation. The applicant shall conduct on-site topographic surveys to locate the precise floodplain line on the subject parcel. Any structure placed within the floodplain shall be anchored firmly to prevent floodwaters from carrying it downstream. Such anchoring shall be sufficient to withstand a flood velocity of six feet per second, and shall require the applicant to submit a written opinion from a registered professional engineer that the proposed structural design meets this standard.

(4)

Sight triangle. On a corner lot in any district or the entry point of a private driveway or street to a public street, new developments shall conform to the requirements of the sight triangle. Within the triangular area formed by the right-of-way lines and a line connecting them at points measured 30 feet back from the end of the curb radius, nothing shall be erected, placed, planted, or allowed to grow in such a manner as to materially impede vision between a height of three feet and eight feet above the grades at the back of the curb of the intersecting streets.

(5)

Off-site improvements. Where off-site roadway or utility improvements are required as a result of the proposed development, those improvements shall be the responsibility of the applicant, and shall be constructed or installed prior to any final inspection or the issuance of an occupancy permit.

(6)

Utilities. All utilities and services shall be located underground.

(7)

Engineering plans. All grading plans, storm water drainage plans, plans for the provision of storm water detention, and the engineering construction plans for roadway and utility improvements shall be reviewed and approved by the city engineer.

(b)

Optional requirements.

(1)

In order to minimize storm water runoff, the amount of the site in impervious surface, such as roofs and pavement, should be minimized.

a.

Less than 50 percent in impervious surface means 30 points.

b.

50 to 65 percent in impervious surface means 20 points.

c.

66 to 75 percent in impervious surface means 10 points.

d.

76 to 85 percent in impervious surface means 0 points.

e.

More than 85 percent in impervious surface is strictly prohibited.

(2)

Smooth topographic transitions should be provided to adjacent properties.

a.

Slopes less than 1:3 rise to run means 20 points.

b.

Slopes at 1:3 rise to run means 10 points.

c.

Slopes greater than 1:3 rise to run means 0 points.

(Ord. of 8-3-99(1), § 1.07(A))