The erosion and sediment control plans shall be prepared by
a person or firm qualified by training and experience to have expert
knowledge of runoff, erosion, and sediment control treatments, including
drainage and related land conservation techniques.
The plans shall contain appropriate information according to
this article.
(§ 1, Ord. 601, eff. May 13, 1982)
The erosion and sediment control plans shall include the following:
(a) Native vegetation.
(1) Descriptions of the native vegetation;
(2) The location of native vegetation whose root zone will be affected
by compaction, fills, trenches, and changes in the groundwater table;
(3) A list of the vegetation to be removed and the criteria used to determine
removal;
(4) When the vegetation shall be removed; the method shall be one which
will minimize the erosive effects from the removal;
(5) Measures which will prevent conditions damaging to vegetation shall
be specified;
(6) In no event shall the native vegetation ground cover be destroyed,
removed, or disturbed more than 15 days prior to grading unless otherwise
approved by the City. Exposure of soil to erosion by removing vegetation
shall be limited to the area required for immediate construction operations;
and
(7) Native vegetation shall be retained, protected, and supplemented
wherever possible; and
(b) Establishment of vegetation. Where the establishment of
vegetation is required on slopes of cut and fill, graded areas, and
watercourses, the following information shall be provided on the plan:
(1) The location and area to be vegetated;
(2) An indication of whether the vegetation is temporary or permanent;
(3) The type and quantity of seeds or plants;
(4) The ground conditions as follows:
(i) The surface condition of the soil;
(iii)
The slope angle, slope length, and aspect; and
(iv)
The nutrients in the soil;
(5) The type and quantity of mulch;
(6) The type and quantity of fertilizer;
(7) The method and schedule of seeding, mulching, planting, and fertilizing;
and
(8) The method and schedule of irrigation.
(§ 1, Ord. 601, eff. May 13, 1982)
Where it is necessary to reduce the increased rate and volume
of rainfall runoff due to the alteration of the runoff pattern, the
following data shall be provided:
(a) The
runoff rate and volume to be expected from a 10 year 24 hour frequency
rainstorm for conditions existing before and after the proposed land
disturbance;
(b) The
location of natural and man-made drainageways;
(c) The
size of the drainage areas above the cuts and slopes;
(d) The
methods to be used to reduce the erosion of drainageways;
(e) The
procedures used to trap sediment in order to protect drainage control
facilities;
(f) The
methods used to prevent or control the rate and direction of runoff
on roadways during and after land disturbances;
(g) The
methods used to control runoff across the slopes of cuts and fills
and graded areas during and after land disturbances;
(h) The
schedule for the construction of drainage protection and control measures;
and
(i) The
method and schedule for the construction of waterway crossings.
(§ 1, Ord. 601, eff. May 13, 1982)
Information on the design criteria of sediment basins shall
include the following:
(a) The
location and dimensions of the sediment basins;
(b) The
hydrologic and sediment transport data used to determine the proper
capacity of the needed basin;
(c) The
construction schedule and procedure;
(d) The
source of borrow materials;
(e) The
type and manner of vegetating the erodible slopes; and
(f) A
maintenance schedule demonstrating firm and fixed periods for the
removal of debris and sediment and repairs to structures. The schedule
and the facility will be subject to annual review by the City Engineer
for compliance.
(§ 1, Ord. 601, eff. May 13, 1982)
The following shall apply to the control of runoff:
(a) Provisions
shall be made to control the increased runoff caused by changed soil
and surface conditions during and after development so that there
will be no increase in runoff and sediment over the predevelopment
condition.
(b) To
prevent excess runoff, the rate of surface water runoff shall be structurally
retarded.
(§ 1, Ord. 601, eff. May 13, 1982)
An applicant requesting permission to make any surface change
shall:
(a) Collect
on-site surface runoff and dispose of it at non-erosive velocities
to the point of discharge into the common natural watercourse of the
drainage area;
(b) Handle
existing and potential off-site runoff through the proposed development
by designing the proposed development to adequately handle storm runoff
from a fully developed area upstream;
(c) Pay his proportionate share of the total cost of off-site drainage control improvements to the common natural watercourse based upon a fully developed drainage area (pursuant to Section
9-10.06 of Chapter 10 of this title);
(d) Provide
and install, at his expense, all drainage, erosion, and sediment control
works (permanent and temporary);
(e) Retain
sediment being transported by runoff water on-site through the use
of sediment basins, silt traps, or similar measures; and
(f) Dispose
of accumulated sediment during dry seasons to maintain the basin capacity.
(§ 1, Ord. 601, eff. May 13, 1982)
The concentration of surface water runoff shall only be permitted
in swales or watercourses.
(§ 1, Ord. 601, eff. May 13, 1982)
In order to prevent polluting discharges from occurring, approved
erosion and sediment control devices shall be required for all grading
and filling. Control devices and measures which may be required include,
but shall not be limited to, the following:
(a) Energy
absorbing devices to reduce the velocity of runoff water;
(b) Sedimentation
controls, such as sediment debris basins and sediment traps. Any trapped
sediment shall be removed to a disposal site approved by the City
Engineer;
(c) The
dispersal of water runoff from developed areas over large undisturbed
areas; and
(d) Multiple
discharge points to reduce the volume of runoff over localized areas.
(§ 1, Ord. 601, eff. May 13, 1982)
Where fill slopes are to be constructed, the following information
shall be included:
(a) The
location of the fill area;
(b) The
slope and height of the fill;
(c) The
slope and condition of the original ground;
(d) The
number and dimensions of benches;
(e) The
source of fill material;
(f) The
ability of the fill to support vegetation;
(g) The
methods of protecting the slope surface of the fill;
(h) The
number and width of the drainage terraces to be installed;
(i) Fills
shall not encroach on natural watercourses or constructed channels;
and
(j) Fills
placed against watercourses shall have suitable protection against
erosion during flooding.
(§ 1, Ord. 601, eff. May 13, 1982)
Where slopes are to be formed from cuts, the following information
shall be included:
(a) The
location of the cuts;
(b) The
slope and height of the cuts;
(c) The
identification of the cuts to be vegetated or not subject to erosion;
(d) The
number and width of the drainage terraces provided; and
(e) The
ability of the ground to support vegetation.
(§ 1, Ord. 601, eff. May 13, 1982)
The following shall apply to slope construction:
(a) Slopes,
both cut and fill, shall not be steeper than two to one (2:1), unless
a thorough geological and engineering analysis indicates that steeper
slopes are safe and erosion control measures are specified.
(b) Slopes
shall not be constructed so as to endanger or disturb adjoining property.
(§ 1, Ord. 601, eff. May 13, 1982)
The following shall apply to slope surface stabilization:
(a) Temporary
mulching, seeding, or other suitable stabilization measures shall
be used to protect exposed critical areas during construction or other
land disturbances.
(b) Earth
or paved interceptors and diversions shall be installed at the top
of cut or fill slopes where there is a potential for surface runoff.
(c) Excavated
materials shall not be deposited or stored in or alongside rivers
or watercourses where the materials can be washed away by high water
or storm runoff.
(§ 1, Ord. 601, eff. May 13, 1982)
Excavated materials removed during grading operations shall
be disposed of as follows:
(a) By
stockpiling all or some of the topsoil on the site for use on areas
to be revegetated;
(b) By
locating stockpiled soil so that, if erosion occurs, it would not
become a source for off-site sediment damage;
(c) By
stockpiling soil far enough from streams or drainageways that surface
runoff cannot carry sediment downstream;
(d) By
stockpiling materials from trenches and pits on the up-slope side
of the excavation;
(e) By
promptly backfilling and compacting stockpiled soil into trenches
and pits to reduce the risk of erosion;
(f) By
applying mulch or other protective coverings on stock-piled material
which will be exposed through the winter season or which faces a high
risk of intensive summer rains; or
(g) By
moving excavated materials not to be used at the site to a location
approved by the City Manager.
(§ 1, Ord. 601, eff. May 13, 1982)
Vegetation removed during clearing operations shall be disposed
of as follows:
(a) By
clipping all of the cleared vegetation for use as mulch or compost
on the site; or
(b) By
disposing of cleared vegetation by hauling it to an approved sanitary
landfill or in a manner and at a location approved by the City Engineer.
(§ 1, Ord. 601, eff. May 13, 1982)