HYDROLOGIC & HYDRAULIC REPORT
ON THE
PROPOSED BRIDGE WATERWAY OPENING
MERCER COUNTY
STATE ROUTE 2025, SECTION BO0
SEGMENT 0020, OFFSET 0000
OVER
BARMORE RUN
Prepared by
Pennsylvania Department of Transportation
Engineering District 1-0
Bridge Unit
June 2005
Mercer County
S.R.2025, Sec. B00
Seg.0020, Off.0000
Over Barmore Run
PROJECT DESCRIPTION NARRATIVE
INTRODUCTION AND SITE DATA
This is a Hydrologic and Hydraulic Report on a deteriorated steel
girder bridge carrying State Route 2025 over Barmore Run in the
Township of Pine, Mercer County, Pennsylvania.
The purpose of this report is to obtain a water obstruction and
encroachment permit for the proposed bridge waterway opening from the
Pennsylvania Department of Environmental Protection and the Pennsylvania
Fish & Boat Commission. Also, a Corp of Engineers “Pennsylvania State
Programmatic General Permit-2.
Available High Water Marks and Information
Mr. John Royle, a 37 year resident of this area, provided the
following high water information. The extreme high water
elevation was approximately 1217.76, he could not recall any
particular time frame of when this happened.
Environmental Effects
Barmore Run is not a navigable stream. It is not a stocked trout
stream because it is not listed in the PaDOT Design Manual, Part
2, Appendix 10-A “Stockable Warm Water and Trout Streams” or the
PA Fish & Boat Commission’s “2004 PA Summary of Fishing
Regulations and Laws”.
The Department of Environmental Protections, Pennsylvania Code,
Chapter 93 Water Quality Standards does not contain a
classification for Barmore Run, therefore past practice of
looking downstream until we find a stream that is listed, came up
with Slippery Rock Creek as a cold water fishes (CWF) stream.
The Pennsylvania Fish and Boat Commission, Division of Fisheries
Management, “Listing of Water having Wild Trout” does not list
Barmore Run.
Pennsylvania Natural Diversity Inventory (PNDI) search form was
submitted to the Pennsylvania Department of Environmental
Protection, Northwest Regional Office. The response (PNDI search
dated 10/08/04) indicates that there is potential to impact a
species of special concern in the project area. Investigations by
the appropriate agency cleared the project site of any impact to
endangered species. (See attachment in PNDI Search Section)
Barmore Run is not listed on the Pennsylvania Scenic River
System.
All pollution control measures and other safety precautions will
be adhered to during the construction of the new structure. (See
attachment in E&S Section)
Refer to the Environmental Assessment Form for further details on
environmental concerns.
Debris and Ice
The stream is flanked on both sides by heavy vegetation and
lawns. There exists some potential for debris accumulation at
this structure. The formation of ice at this site will not
change the effectiveness of the structure or the stream flow.
The proposed replacement structure has the same span and channel
length with a larger underclearance waterway opening.
Nature of Streambed and Bank Stability
The streambed is composed of sand and silt with small to meduim
cobblestones. The stream banks are covered with a heavy growth
of vegetation and lawns. The banks are relatively stable as
there is only minor erosion in the vicinity of this structure.
Water Stage Factors
There is a dam/spillway and lake in the drainage area but with no
affect on the natural stream stage. The project area is not
within any flood control structure.
Site Inspection Information
Members of the District 1-0 Bridge Unit made a field inspection
of the subject bridge site. The drainage area consists of
forest, wetlands with heavy thick vegetation and contoured grassy
areas. The existing structure is located in a rural area with
some growth potential. No change in hydrologic characteristics is
expected to occur within the life span of the new bridge.
Line and Grade
The grade and alignment of the roadway will remain the same as
that of the existing.
Skew of Crossing and Bridge Position
The skew of the proposed structure will be 90 degrees, the skew
of the existing structure is 90 degrees. The proposed structure
centerline will be the same as the existing structure centerline
and stationing.
HYDROLOGIC ANLYSIS
Drainage Area
The area which drains into Wolf Creek is 2.68 Square Miles. All
non-contributing basins located within this area are also
included. WMS (Watershed Management System) and a Planimeter were
used to determine the drainage area from a portion of the 7.5'
series U.S.G.S. Map.
Flood Discharges
Flood Discharges (Q) for this drainage area were calculated using
the TR-55 Method to come up with the estimated peak rate of
runoff. The interpolated design (25 Year) and Basic (100 Year)
flood discharges are 306.54 cfs and 453.17 cfs.
HYDRAULIC ANALYSIS AND DESIGN
FEMA Flood Maps
No detailed Federal Emergency Management Agency (FEMA) flood maps
are available for this area.
Allowable Stream Velocity and Headwater
The maximum allowable velocity in a channel with a streambed of
fine sand and sandy loam is 2.5 fps. (PaDOT Design Manual, Part
2, Table 2.13.2)
An allowable headwater elevation of 1220.00 was used for design.
This figure corresponds to the minimum bottom of superstructure.
No structure roadway inundation or property damage will occur
during a flood of this stage elevation
Performance of Existing and Proposed Structures
Hydraulic performance of the existing and proposed structures
were determined using the HEC-RAS program. The proposed structure
will perform the same as the existing structure at this location.
The existing structure has no flood problems.
The following table is a summary of the HEC-RAS Analysis.
Structure
Type
Existing
Steel
Stringer
Bridge
Proposed
Twin Cell
Box
Culvert
Design
(25-YR.)
Headwater
Design
(25-YR.)
Velocity
Basic
(100-YR.)
Headwater
Basic
(100-YR)
Velocity
1217.11
1.86 FPS
1217.29
2.20 FPS
1217.32
1.85 FPS
1217.82
2.20 FPS
Scour Analysis
The bridge inspection reports for this site show no scour problem
exist.
Recommended Structure Opening
The existing steel girder bridge has a span of 30.00 feet and a
vertical clearance of 4.00 feet. The proposed box culvert will
have 2 spans of 15.00 feet and a vertical clear of 7.00 feet.
Temporary Facilities for Construction
A temporary roadway will not be provided for this project. A
detour will maintain traffic during the construction of the
proposed bridge.
The stream flow will be maintained at all times during
construction. Every attempt will be made to discourage erosion
and siltation during the construction period. An approved
Erosion and Sedimentation (E&S) Pollution Control Plan will be
properly implemented and closely monitored during construction.
All equipment and materials will be removed from the site and
disposed of or stored in an environmentally safe manner at the
completion of the project. Construction of this project is
expected to last approximately 3 months.
A. SUMMARY DATA
1.
Site Data
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
l.
2.
Route: S.R. 2025
Segment/Offset: 0020/0000 (Sta. 186+20)
County: Mercer
Township: Pine Township
Stream: Barmore Run
Drainage Area: 2.68 Square Miles
Location: U.S.G.S.(7.5’ Series) Grove City,PA Quadrangle Map
Longitude: 80o06’17” west of Greenwich Meridian
Latitude: 41o08’41” north of equator
Average channel top width: 30 feet
Average channel bottom width: 28 feet
Average channel depth: 4 feet
Pertinent Elevation
200’ U/S
200’D/S
Streambed Elevations
1215.00
1213.00
Average Flow Depth:
2 feet
Proposed Structure Data
a.
Type: Twin Cell Box Culvert
b.
c.
d.
e.
Span: 1
Clear Span: 30’-0” Underclearance:
Skew: 90 degrees
Bridge width: 30’-0” curb to curb
7’-0”
PERSONNEL INVOLVED IN THE PREPARATION OF THIS REPORT
Name
Theodore J. Tarr
Position
Bridge & Structural
Drafter/Designer
Autumn Kelley
Assistant Environmental
Manager
Involvement
Misc. correspondence
Plan Preparation
Report Preparation
Wetland Identification
Alternatives Analysis
The project involves the replacement of a deteriorated one span steel
girder bridge. The proposed structure will be located on the same
alignment and profile as the existing bridge. The following
alternatives were evaluated throughout the preliminary design process:
1.
2.
Rehabilitation of the existing structure is not a feasible
alternative due to the excessive deterioration of the
superstructure.
A no action alternative would result in placing lower weight
restrictions on the structure which would limit most motor
traffic.