HomeMy WebLinkAboutJasper Slough narrativeJasper Slough Wildlife Viewing Platform
Narrative for Site Plan Review and
Floodplain Overlay District Development applications
1.0 Introduction
Willamalane has received a Local Government Grant Program award to construct a wildlife viewing
platform at the Jasper Slough, adjacent to the Mill Race Path close to the Jasper Road trailhead. The
intention of the platform is to allow a place to view Western pond turtles and other wildlife, and to limit
resource damage from foot traffic along the edges of the Jasper Slough adjacent to the Mill Race Path.
1.1 Applicant’s request
Willamalane requests approval of the project through Site Plan Review and Floodplain Overlay District
development approval.
1.2 Existing Use
The location of the proposed viewing platform is currently long grass and other vegetation between the
paved Mill Race Path and the Jasper Slough. Users of the path often detour from the path at this location
towards the slough to view wildlife including Western pond turtles that bask on logs in the slough. This
foot traffic can potentially impact turtle nesting sites.
1.3 Land Use Requirements and Environmental Constraints
The site is zoned and designated as Public Land and Open Space (PLO), to which the proposed used
complies with city zoning requirements.
The site is within the 1-year TOTZ for wellhead protection. The site is partially within the 100 year
floodplain. Wetlands are located on site according to Springfield’s Local Wetland Inventory, and according
to a wetland delineation done during the construction of the Mill Race Path. The slough is classified as
Water Quality Limited Watercourse (<1000 cfs)
According to the Natural Resources Conservation Service website mapping services, the existing soil
type is Chapman loam (NRCS soil #24), and loam or gravelly sandy loam is expected to be encountered.
Drainage class is “well drained”. A geotechnical investigation is scheduled for January 2024 and will
inform the final structural engineering design for the platform.
A wetland delineation was completed in this area as part of the Mill Race Path development in 2016 and
is available if required.
1.4 Proposed Development
The wildlife viewing platform will be a simple wooden deck structure with steel handrails. The platform is
16’ x 36’ in size. Interpretive signage will be installed at the platform, and possibly one or two picnic tables
or benches provided. Following construction, Willamalane natural resources staff will add to some of the
recent native planting to improve and protect wildlife habitat. A small portion of concrete paving will be
installed to provide a connection to the Mill Race Path. The paving is adjacent to, and partly within, the
newly constructed gravel emergency access easement for the Mountainvale subdivision. The concrete
will be reinforced and be available as part of the emergency access route. No vertical structures will be
placed within this easement.
1.5 Utilities
No utilities are within the project disturbance area, or will be installed with the platform.
1.6 Springfield Development Code (SDC) Review Criteria
To approve the proposed application, it must be found that the request complies with the applicable
criteria as outlined in the SDC. Approval of the land use applications is contingent upon an applicant
demonstrating that the subject proposal is consistent with the SDC chapter 4 development standards.
To facilitate a review of Willamalane’s proposal for Jasper Wildlife Viewing Platform, this narrative
addresses those sections of the SDC that are deemed relevant to the application. Only the criteria to
which a response is deemed necessary has been included in the following paragraphs.
1.7 Site Plan Review application
Willamalane’s response to the SDC sections deemed applicable is as follows:
3.2-715 Base Zone Development Standards
The viewing platform is within the 20’ residential setback from the adjacent City property. Per email from
Liz Miller dated February 7th, 2024, this setback will not apply to this application.
4.3-110 Stormwater Management
D. Run-off from a development shall be directed to an approved stormwater
management system with sufficient capacity to accept the discharge. Where the
Public Works Director determines that the additional run-off resulting from the
development will overload an existing stormwater management system, the
Approval Authority shall withhold Development Approval until provisions,
consistent with the Engineering Design Standards and Procedures Manual, have
been made to correct or mitigate this condition.
Storm water runoff from the new concrete sidewalks (area < 400 s.f.) will be directed to run off into
adjacent landscape areas of grass. The deck of the platform will be constructed of timber boards with
gaps between each board typical of deck construction that allows storm water to drain through to the
natural pervious surface below. This should not have any meaningful effect on riparian area functions,
stormwater flows, or riparian habitat.
4.3-115 Water Quality Protection
C. For protection of water quality and protection of riparian area functions as
specified in SDC 4.3.110, the following standards apply:
(5) Utilize Native Vegetation in Riparian Areas. The required riparian
area landscaping must be installed as part of the building permit process
and may be bonded as specified in SDC 5.17.150.
All vegetation installed as part of the project will be native, and will be intended to improve wetland habitat
at this location.
F. The following uses and activities must be permitted within the development
setback area only, provided all required Federal, State, or local permits are
secured:
(5) Public multi-use paths, access ways, trails, picnic areas, or
interpretive and educational displays and overlooks, including benches
and outdoor furniture; and
(6) Wetland and riparian restoration.
The two main elements of the project are to install an area that improves opportunities for interpretation
and education, and to restore the riparian area by providing a dedicated location for wildlife viewing in an
effort to restrain foot traffic throughout the bank areas of the slough. Activities and development are not
expected to trigger any federal or state permit requirements.
4.4.105 Landscaping
(I) Planting Installation Standards.
(2) Existing trees to be retained on private property must not have
construction occur within the drip line, unless a landscape architect
certifies that affected trees will not have at least a 90 percent chance of
survival over a 5-year period. Trees to be retained must be provided with
protection with at least a 3-foot-tall temporary fence barrier around the drip
line and include protection around the tree to prevent abrasion to the tree.
The trees to be retained and the method of protection must be included on
the Landscape Plan.
Existing trees to be retained within the construction zone will be protected by temporary fencing per the
Demolition Plan.
4.6.155 Bicycle Parking – Number of Spaces Required
Bicycle parking for a viewing platform is not specifically required in the SDC, but two spaces will be
provided. These will be outside of the emergency access easement. Further bike parking is available at
the adjacent trailhead.
4.7.203 Public Land and Open Space
(A) Primary access shall be on arterial or collector streets except as provided or
exempted elsewhere in SDC 3.2.700.
The viewing platform is intended to be accessed on foot or by bike from the Mill Race Path. The Jasper
Road Trailhead is adjacent to the platform and is easily accessed from Jasper Road.
1.8 Floodplain Overlay District Development application
As advised by City Planner Kelly Notary in an email to Simon Daws on December 20, 2023, this project is
not classified as a structure, but does meet the definition of a development, and that section 3.3.430
(A)(1-4) of the SDC would apply with regard to development within the Floodplain Overlay District.
Willamalane’s response to the SDC sections deemed applicable is as follows:
3.3.430 Development Standards.
(A) General Standards. In all special flood hazard areas within the UGB, the following
standards shall be adhered to:
(1) Alteration of Watercourse. Require that the flood carrying capacity within the
altered or relocated portion of said watercourse is maintained. Require that
maintenance is provided within the altered or relocated portion of said watercourse
to ensure that the flood carrying capacity is not diminished. Require compliance
with SDC 3.3.425(C)(3)(b) and SDC 3.3.425(C)(3)(c).
The viewing platform or any associated improvements will not alter the watercourse of the Jasper Slough.
(2) Anchoring. All new construction and substantial improvements shall be
anchored to prevent flotation, collapse or lateral movement of the structure resulting
from hydrodynamic and hydrostatic loads, including the effects of buoyancy. All
manufactured dwellings shall be anchored per SDC 3.3.430(B)(3)(d).
The platform will be mounted on timber posts embedded in concrete footings. The exact size of the post
and footings is to be determined based on pending geotechnical investigations and final structural design
of the platform. This information will be updated in future submissions for Site Plan Review and structural
permit.
(3) Construction Materials and Methods.
(a) All new construction and substantial improvements shall be constructed
with materials and utility equipment resistant to flood damage.
(b) All new construction and substantial improvements shall be constructed
using methods and practices that minimize flood damage.
The platform will be built with structural grade lumber and steel, and connections that are designed to
meet commercial requirements for this kind of structure. Structural engineering calculations and design
will ensure the viewing platform is resistant to flood damage.
(4) Utilities and Equipment.
(a) Electrical, Mechanical, Plumbing, and Other Equipment. Electrical,
heating, ventilation, air-conditioning, plumbing, duct systems, and other
equipment and service facilities shall be elevated at or above the base flood
elevation or shall be designed and installed to prevent water from entering or
accumulating within the components and to resist hydrostatic and
hydrodynamic loads and stresses, including the effects of buoyancy, during
conditions of flooding. In addition, electrical, heating, ventilating, air-
conditioning, plumbing, duct systems, and other equipment and service
facilities shall meet all the requirements of this section if replaced as part of a
substantial improvement.
(b) Water Supply, Sanitary Sewer, and On-Site Waste Disposal Systems.
(i) All new and replacement water supply systems shall be designed to
minimize or eliminate infiltration of flood waters into the system.
(ii) New and replacement sanitary sewage systems shall be designed to
minimize or eliminate infiltration of flood waters into the systems and
discharge from the systems into flood waters.
(iii) On-site waste disposal systems shall be located to avoid
impairment to them or contamination from them during flooding consistent
with the Oregon Department of Environmental Quality.
No utilities as described above exist on site, or are proposed to be installed as part of this development.
1.8 Attachments
The following attachments are provided in support of the Site Plan Review application.
A. Copy of plan set at 11”x 17”
C0.00 Cover Sheet
C1.00 Existing Conditions
C1.01 Demolition Plan
C2.00 Site Plan
C2.01 Site Layout
C2.50 Site Details
C2.51 Site Details
B. Copy of the Deed
C. National Flood Hazard Layer FIRMette (FEMA) for the site. Note that base flood elevations on
this map are in NGVD29 vertical control datum, and the elevation data on the site plans are in
NAVD88. 3.6’ should be added to the FEMA elevations to convert
Submitted: February 2024
Simon Daws, Landscape Architect
Willamalane Park & Recreation District