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Planning with Surface and Ground Waters :
After spending
time evaluating the drainage characteristics of your
property, completing the checklist and locating potential
problem areas, you may feel ready to start taking action
on your drainage issues. However, before you go forward
you should take advantage of published information,
public agency guidance, and opinions from technical
experts in specific areas (see links section for more
information). Seeking additional resources and guidance
will allow you to clarify or modify your checklist notes
on your property. You should resist jumping from your
initial property observations directly to the installation
of drainage control elements. If you spend just a little
time with site planning, you may be able to pull the
pieces of your drainage observations into a coordinated
system which can help you avoid relocating problems
from one area to another.
Creating
a Property Drawing
Elements of the Drawing
Regulations and Ordinances
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Creating
a Property Drawing
Making a plan (drawing) is the best way to organize
your drainage control system and is certainly the best
way to communicate your approach to others. We have
provided an example drawing. Nearly everyone feels comfortable
with pictures. Your drawing will help everyone associated
with your property clearly know the nature and extent
of your proposed work. Governmental agencies that may
be involved in project permit approval usually request
if not require a property drawing or plan. The drawing
may be part of a more formal submittal to an agency
usually called a drainage control plan. The plan may
include a drawing of your property and some written
descriptions of the project. Regardless of the different
reasons for a plan, it is in your interest to create
a drawing because of the following:
A drawing helps
you cost-effectively coordinate and locate your planned
improvements in relation to other property features;
A drawing helps you clearly communicate your drainage
control goals to potential contractors which should
help you obtain good work proposals and accurate cost
estimates;
A drawing helps avoid damage to property;
A drawing helps form a basis of communication between
property owners, contractors, and agencies that is clear
and positive; and
A drawing can be used to record locations of constructed
drainage improvements.
Elements
of the Drawing
There are three primary types of information you are
likely to put on your drawing: general topography, existing
features, and planned features. Each of these pieces
of information is fairly easy to acquire. For topography
you have the choice of either hiring a professional
surveyor to do a boundary and topographic survey or
generating portions of the plan yourself. If the planning
area is small with the topography contours and boundary
lines easily established, you may decide to undertake
the work yourself. To begin the drawing, you must identify
the locations of your property corners and general property
dimensions. You will need a pencil, a protractor, straight
edge and an engineer's scale or ruler in order to sketch
the configuration of your property on a large sheet
of paper. Using a scale of one inch on paper equals
20 feet on your property usually works fine for most
sites where the planning area is restricted to under
an acre. Otherwise, you can use a scale of one inch
equals 30 feet or greater.
Setting topographic
contours or grades in a small open area of roughly a
couple hundred feet square can be performed measuring
or estimating the vertical drop per 100 feet. The feet
dropped in 100 feet equals the average slope angle in
percent (i.e. 2 feet in 100 feet equals 2 percent).
On steep slopes, you may be able to only approximate
the grade but still be sure to identify the locations
of your observed features.
For most sites
there are enough complex issues or enough area to cover
that it helps to hire a surveyor to do a topographic
site plan. The surveyor can also locate any existing
features on your property that you identify. The locations
of roads, houses, landscaping, outbuildings, the top
and bottom of slopes, existing drainage features, and
septic systems can all be included in your topographic
survey work. Remember to check any survey against what
you actually observe on your property. Typically, you
will need to add more detail to your plan than what
is shown.
Now that you have
most of the information shown on your plan, the last
remaining bit of information is to identify features
that are part of any planned construction. With your
plan showing existing site information you can now locate
potential drainage improvements on your site. Review
this booklet along with other references before choosing
the final location any proposed drainage system improvements.
The Department
of Ecology Water Quality Program as part of the Puget
Sound Water Quality Management Plan suggests that both
small and large parcel construction projects put together
an Erosion and Sediment Control Plan. The Water Quality
Program identifies small parcels as properties having:
individual, detached single family residences and duplexes;
created or added less than 5,000 square feet of impervious
area (driveways, parking lots, roof area, etc.); and
land disturbing activities of less than one acre. Your
plan may satisfy all or part of any erosion and sediment
control plan. Check with your local public works department
for more details on specific drainage or drainage plan
requirements. A typical drainage plan package submitted
to your local building and planning office usually includes
the following basic information: location of property
and physical description of the property; a scaled plan
(drawing) of the property showing accurate locations
of existing and proposed structures and topography;
locations of drainage system(s) and erosion control
measures; limits of site disturbances; locations of
any required setbacks and critical areas; and identification
of the final points or areas of water discharge.
Regulations
and Ordinances
Transfer interrupted!
habitats, requires that an HPA (Hydraulics Project Approval)
be obtained for any work that occurs in state waters.
An HPA will typically be required for shoreline bulkheading,
placement of drainage outfalls below the ordinary high
water line, or any modification of the beach.
Coastal bluffs
are sensitive ecological areas and may be identified
as critical habitats or may support rare or protected
wildlife species. Heron rookeries and trees used as
eagle nest sites are examples of protected habitat areas.
Contact your local planning office or the Department
of Fish and Wildlife's Habitat Division.
The Shoreline Management
Act (SMA) applies to many activities that occur within
200 feet of the shoreline. Each local government administers
the SMA through its Shoreline Master Program and each
jurisdiction may regulate activities differently. Contact
your local planning office to see what activities require
a shoreline substantial development permit and which
are exempt on your particular shoreline.
Local jurisdictions
may require permits or approvals for some types of drainage
work. In general, individual property owners are not
subject to permit requirements for stormwater control
and discharge. Outfalls from subdivisions larger than
5 acres may be required to obtain an NPDES (National
Pollution Discharge Elimination Standard) permit. Contact
your planning and public works departments or the Ecology
water quality program staff at the Permit Coordination
Center for more specific information that affects your
property.
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