B08_Solicitation_Attachment_2_SOW_Culvert_Removal.pdf

STATEMENT OF WORK (SOW)

Katahdin Woods and Waters (KAWW) National Monument Replace Substandard Culverts and Bridges, Penobscot

County, Maine PMIS KAWW 314638A- Culvert Removals on Unnamed Tributaries Orin Falls

Road T3-R8 WELS #7241, 7282, 7662, 7663

1.0 Background

Project is located in the National Park Service unit, Katahdin Woods and Waters National Monument (KAWW), located in Penobscot County of Northern Maine.

Katahdin Woods and Waters National Monument includes more than 80,000 acres and several hundred miles of aggregate-surface logging roads customary to the Maine Northern Woods. This contract will remove four culvert systems and restore natural stream flow. Crossings consist of existing culverts which are presenting a barrier to natural waterflow to the headwaters.

2.0 Scope

This contract requires the contractor to provide all tools, labor, equipment, supervision, transportation, and materials necessary to remove existing culvert systems and restore natural waterflow. Work is to be done in accordance with all existing Federal, State, and local codes.

Crossing 7241: The removal plan calls for a cross section at the current road location with a restored but limited floodplain area with a total width of approximately 15'. The elevation of the stream bed at the trail crossing will be lowered to ≈ 603.25'. The stream will have a cross-sectional area of approximately 3 square feet, with banks ≈ 0.5' high.

The overall slope of the stream in this area will remain ≈ 0.4%. Analysis of likely peak flows in this watershed using HY-8 hydraulic analysis software indicates the proposed trail crossing area will successfully pass more than the expected 1% AEP peak flow of < 10 cfs. Ensuring that the stream can be crossed occasionally by a light vehicle, the bed will consist of a layer of cobble, with bank armor rock which even large flows should not disturb. (Attachment 2)

Crossing 7282: The removal plan calls for a cross section at the current road location with a restored but limited floodplain area with a total width of just over 20'. The elevation of the stream bed at the trail crossing will be lowered to ≈ 596.75'. The stream will have a cross-sectional area of approximately 9 square feet, with banks ≈ 1' high.

The overall slope of stream in this area will remain ≈ 0.5%. Analysis of likely peak flows in this watershed using HY-8 hydraulic analysis software indicates the proposed trail crossing area will successfully pass more than the expected 1% AEP peak flow of almost 200 cfs. Ensuring that the stream can be crossed occasionally by a light vehicle, the bed will consist of a layer of cobble, with bank armor rock installed to allow easy passage of such a vehicle. (Attachment 3)

Crossing 7662: The removal plan calls for a cross section at the current road location with a restored but limited floodplain area with a total width of just over 20'. The elevation of the stream bed at the trail crossing will be lowered to ≈ 657'. The stream will have a cross-sectional area of approximately 6 square feet, with banks ≈ 1' high. This bank height should constrain dominant flows to the channel, continuing to erode the stream bed over time to reach a sustainable overall slope of ≈ 2.5%. Analysis of likely peak flows in this watershed using HY-8 hydraulic analysis software indicates the proposed trail crossing area will successfully pass more than the expected 1% AEP peak flow of 82 cfs. Ensuring that the stream can make the transition from its current aggraded form to a more naturally sustainable gradient requires a fair amount of regrading of the existing unnaturally high floodplain and stream bed as indicated on attached topographic map. (Attachment 4)

Crossing 7663: The removal plan calls for a cross section at the current road location with a restored but limited floodplain area with a total width of ≈ 30'. The elevation of the stream bed at the trail crossing will be lowered to ≈ 647'. The stream will have a constructed bank full width of ≈ 11' with a cross-sectional area of approximately 9 square feet, with banks ≈ 1' high, with some rocks will also be placed as steppingstones to provide easier passage of pedestrian trail users. Analysis of likely peak flows in this watershed using HY-8 hydraulic analysis software indicates the proposed trail crossing area will successfully pass more than the expected 1% AEP peak flow of 133 cfs.

Ensuring that the stream can make the transition from its current somewhat aggraded form to a more naturally sustainable gradient requires a fair amount of regrading of the existing unnaturally high floodplain and stream bed as indicated on attached topographic map. (Attachment 5)

3.0 Objectives

The objective of this contract is to remove existing culverts and fully restore stream system systems to natural waterflow.

4.0 Tasks

Remove Culverts: Culverts are on the Orin Falls Road accessed from the Katahdin Katahdin Loop Road T3-R8 WELS in Penobscot County – See Attachment 1 Location Map and Specifications.

1. Culverts – Removal of road culverts work includes, removal of existing culverts and any associated culvert materials, stream bed restoration, gravel roadway reconstruction, and culvert approach work. Culvert removal and stream restoration will be completed to the specs of attached removal plans. Dewatering will be required.

2. Detailed information for the Culvert Removal Project at Orin Falls Road

Restoration project is attached. Attachment 1, Location Map and Specifications, includes a map of the project location. Attachments 2-5 included proposed crossing inlet elevations, a partial list of materials, and information on water control.

3. Quote Item: Remove/Restore four Road Culvert Systems to accommodate natural waterflow.

5.0 Delivery

• The Contractor shall provide all tools, labor, equipment, supervision, transportation, and materials necessary to repair the roads and stream crossing.

• All work to take place will be within Katahdin Woods and Waters National

Monument (KAWW), located in Penobscot County of Northern Maine.

• The contractor will be required to provide a temporary bridge system that can be overlayed atop existing bridge over Katahdin Brook. The span will need to be greater than 45’ and rated to hold contractors’ equipment. This crossing provides access to all removal projects.

• Contractor is responsible for providing all coble and stone bank armoring for project.

• The Contractor shall submit a safety plan to the Contracting Officer prior to performing any work under this contract.

• The Contractor shall submit a work schedule and sequence of events to the

Contracting Officer prior to performing any work under this contract. There will be a pre-construction meeting held prior to the start of work on-site.

• The contractor shall submit a plan for traffic control for any road closures. All signs and traffic control shall be the contractor’s responsibility. Road closure of up to 2 weeks is allowable. Contractor must give 2 weeks’ notice prior to the closure.

• The contractor will follow attached dewatering and watercourse management plans for the stream work.

• A final inspection must be held with the government upon completion of the work.

• All vehicles and equipment shall be cleaned of any dirt or vegetation, particularly on the undercarriage, tracks, and sprockets before coming to the jobsite.

6.0 Government-Furnished Property

The Government will not be furnishing nor providing any property to the contractor for this contract. Excess excavated material due to the culvert replacement can be deposited within 4 miles of the project. Offsite disposal of the old culvert components and will be the contractor’s responsibility.

7.0 Security

Contractor shall be responsible for securing the work site, materials, equipment, and tools during the duration of the contract. If a temporary staging area is required, KAWW may identify and agree to a location with KAWW. The Government will take no responsibility for lost, stolen or damaged property as a result.

8.0 Place of Performance

The contract work shall be performed on the Orin Falls Road Road within Katahdin Woods and Waters National Monument (KAWW), located in Penobscot County, Maine.

9.0 Period of Performance

The onsite work can only be done between the 15th of July and the 30th of September in any calendar year. The period of performance for this contract begins with a notice to proceed and shall end on 30 September 2025.

Submittals identified in Section 5.0 shall be provided to the Government within 14 days of award of this contract for review and approval. It is anticipated that the Government will require a minimum of 5 business days to review the submission.

Once the submittals are approved by the NPS, the contractor shall commence work, completing it within the period of performance specified above.

Attachment 1

Orin Falls Road Culvert Removals

Orin Falls Road Culverts

Orin Falls Road Culvert Removals

Orin Falls Road Culverts

Attachment 2

#7241

Site Map - Topography

Crossing Site

Site Map - Orthophoto

Inlet Photo Outlet Photo

Upstream Photo Downstream Photo

Site Topography - Existing Conditions

Stream Profile - Existing Conditions

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Existing 1' diameter culvert

Wassataquoik Stream

Back Channel

Beaver Dam

Substrate Assessment - Downstream Riffle (Not representative as reference cross section)

Overall reach substrate primarily sand and organics, with one riffle downstream containing somewhat larger material as indicated in the histogram below based on an abbreviated pebble count:

Site Topography - Proposed Crossing

Fill Information:

Permanent Fill = 50 sq. ft.

Temporary Fill = 30 sq. ft.

Area of regrading road approaches and proposed culvert removal location

Proposed Profile View

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Removed Culvert

Hardened Ford Area

Overall Restoration Reach Slope = 0.4 %

Existing Stream Bed

Expected Stream Bed

Wassataquoik Stream

Back Channel

Some Agraded Sediment

Proposed Restoration Area Elevation - View Downstream at Former Inlet

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Existing 1' Culvert

0.8 ft2

5' Bankfull Width

Elevation

603.25'Bank & Bed Rock

NW/Left Bank SE/Right Bank

1% AEP Flow

Proposed Restoration Area Profile

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Bed and Bank Schematic:

Banklines are composed of 12 inch (average intermediate dimension – not longest or shortest measure) competent, sub-angular foundation rock. Banklines must connect to the natural stream banks to provide a relatively seemless connection to the floodplain. Additional smaller rock is also necessary for filling gaps in the larger material to provde more stable banklines.

The stream bed in the area of the planned crossing is to be composed of 6 inch rounded rock shaped to have a slightly rounded or V-shaped bottom to focus low flows into a slightly concentrated "low-flow" channel.

Stepping stones will be placed at the downstream end of the hardened channel to assist hikers to cross the stream easily at most low flows.

"Inlet" Elevation

603.25'

Flow

Plan View

New Floodplain

Bank Armor Rocks Existing Stream Bed

Expected Stream Bed

Bed Armor Rocks Stepping Stones

Hydrology & Hydraulic Analysis

HY-8 Hydraulic Analysis Program of the U.S. Federal Highway Administration provides results for the above peak flow estimates for the proposed arch design, and indicates that the restored crossing area as proposed will easily pass the expected 1% AEP flow/storm event.

Note that prediction errors are quite large when using regression equations to estimate flows and bankfull widths based on drainage area. It is best to account for potentially larger flows at these return intervals.

Discharge Names

Total Discharge

(cfs)

Headwater Elevation

(ft)

Flow Type

Outlet Depth

(ft)

Outlet Velocity

(ft/s) 99 1.00 603.54 3-M2t 0.19 1.72

50 1.00 603.54 3-M2t 0.19 1.72

20 2.00 603.66 3-M2t 0.29 1.97

10 3.00 603.76 3-M2t 0.37 2.17

4 4.00 603.85 3-M2t 0.44 2.33

2 6.00 603.99 3-M2t 0.56 2.46

1 7.00 604.03 3-M2t 0.62 2.37

0.2 10.00 604.19 3-M2t 0.77~ 1.96

Attribute Value Units Definition References:

Drainage Area 0.01 sq. miles Area that drains to crossing 99 1

Wetlands 5 percent Percentage of NWI storage 50 1

Elevation 615 feet Mean basin elevation 20 2

Precipitation 43.9 inches Mean annual precipitation 10 3

Aquifer Unknown percent 4 4

2 6

X-coordinate 521489 State Plane m Basin centroid E/W location 1 7

Y-coordinate 5087057 State Plane m Basin centroid N/S location 0.2 10

Return

Probability (%)

Peak QT

(ft3/s)1

1 Lombard, P.J., and Hodgkins, G.A.,2020, Estimating flood magnitude and frequency ongaged and ungaged streams in Maine: U.S. Geological Survey Scientific

InvestigationsReport 2020–5092, 56 p.

(https://doi.org/10.3133/sir20205092)Percentage of land underlain by sand & gravel aquifers

Water Control:

Material & Equipment Specifications:

It is critical that water be controlled during construction, both allowing free flow of the stream through the site, and eliminating potential sedimentation and erosion. Any fish must thoroughly and carefully be removed and excluded from the work site before in-stream work begins (including properly screening pump intakes). All Maine Department of

Environmental Protection Best Management Practices for Sediment and Erosion Control should be followed. The existing culvert cannot be left in place during the construction process since the crossing is being decommissioned. Sandbag cofferdams must be placed to control stream flow for pumping around the site. Dirty water must be removed from the work site and filtered in nearby forest to avoid contamination of the stream. Sufficient pump capacity and length of discharge hoses are essential to maintain water control, with backup pumps on hand or readily available. Refer to the map below for likely placement of water control elements.

Removal of existing culvert Dirty water pumped from work site Dirty water filtered in nearby forest

Rock for scour protection and bed features: While some rock may be found on site, the following total volumes must be available:

12" sub-angular bank rock @ ≈ 2-3 yards 6" rounded rock for stream bed armoring @ ≈ 2.5 yards

Sandbags for Cofferdams: 20 small, preferrably poly bagged Polyethylene Sheeting (6 mil - for cofferdam sealing as needed)

Pump conveys streamflow during construction

Water Control: Cofferdam, Pump & Filtration Placement

Cofferdam

Dirty Water Pump

Clean Water Pump

Block Net

Block Net

Filtration Basins

Magnetic Nail in base of birch tree

Elevation Control:

One "temporary" benchmark was set at the time of survey in 2024, and its location should be easy to determine given the bright pink flagging used to mark

it. The photo below should help to determine its location, along with the topographic map images above.

TBM1 - ≈ 40' E from crossing center

Attachment 3

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Existing 3' diameter culvert

CrossSection

Wassataquoik Stream

Back Channel

Cross Section

Beaver Dam Impoundment

Beaver Dam

Beaver Dam

Cross Section 1 - Upstream of Crossing (Not representative due to backwater and proximity to blocked culvert)

Upstream at Cross Section Downstream at Cross Section

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Bankfull Width?

Substrate: All sand and fine gravel - no distribution taken

Bankfull Width: 25'

Bankfull Depth: 2'

Bankfull XS Area: 50 ft2

* Bankfull Dimensions Not Likely Representative

Cross Section 2 - Downstream (Tailwater Control) of Crossing (Not representative due to tailwater scour and proximity to blocked culvert)

Notes: This cross-section is not meant as an ideal reference for crossing design.

* Substrate is not representative of natural stream in this reach - no distribution taken.

This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Bankfull Width

Substrate:

Gravel/Cobble * Bankfull Width: 12.5'

Bankfull Depth: 0.75'

Bankfull XS Area: 9 ft2

Permanent Fill = 100 sq. ft.

Temporary Fill = 80 sq. ft.

Area of regrading road approaches and proposed culvert removal location

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Removed Culvert

Hardened Ford Area

Overall Restoration Reach Slope = 0.5 %

Existing Stream Bed

Expected Stream Bed

Wassataquoik Stream

Back Channel

Some Agraded Sedimnent

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Existing 3' Culvert

7 ft2 10.5' Bankfull Width

Elevation

596.75'

Bank & Bed Rock

NW/Left Bank SE/Right Bank

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Banklines are composed of 12 - 18 inch (average intermediate dimension – not longest or shortest measure) competent, sub-angular foundation rock. Banklines must connect to the natural stream banks to provide a relatively seemless connection to the floodplain. Additional smaller rock is also necessary for filling gaps in the larger material to provde more stable banklines.

The stream bed in the area of the planned crossing is to be composed of 6 - 12 inch rounded rock shaped to have a slightly rounded or V-shaped bottom to focus low flows into a slightly concentrated "low-flow" channel.

Stepping stones will be placed at the downstream end of the hardened channel to assist hikers to cross the stream easily at most low flows.

"Inlet" Elevation

596.75'

Flow

Plan View

New Floodplain

Removed Aggraded Sediments

Bank Armor Rocks

Existing Stream Bed

Expected Stream Bed Bed Armor Rocks

Stepping Stones

HY-8 Hydraulic Analysis Program of the U.S. Federal Highway Administration provides results for the above peak flow estimates for the proposed arch design, and indicates that the

Note that prediction errors are quite large when using regression equations to estimate flows and bankfull widths based on drainage area. It is best to

Total Discharge

(cfs)

Headwater Elevation

(ft)

Flow Type

Outlet Depth

(ft)

Outlet Velocity

(ft/s) 99 35.00 598.17 2-M2c 0.94 4.58

50 50.50 598.40 2-M2c 1.18 4.44

20 83.10 598.76 3-M2t 1.58 4.00

10 107.60 599.00 3-M2t 1.88 3.74

4 141.70 599.31 3-M1t 2.23 3.57

2 169.70 599.56 3-M1t 2.50 3.49

1 199.50 599.81 3-M1t 2.76 3.44

0.2 277.80 600.40 3-M1t 3.37 3.40

Attribute Value Units Definition References:

Drainage Area 0.92 sq. miles Area that drains to crossing 99 35

Wetlands 4 percent Percentage of NWI storage 50 77

Elevation 857 feet Mean basin elevation 20 125

Precipitation 43.9 inches Mean annual precipitation 10 161

Aquifer 8.5 percent 4 211

2 251

X-coordinate 520405 State Plane m Basin centroid E/W location 1 293

Y-coordinate 5086902 State Plane m Basin centroid N/S location 0.2 400

Return

Probability (%)

Peak QT

(ft3/s)1

1 Lombard, P.J., and Hodgkins, G.A.,2020, Estimating flood magnitude and frequency ongaged and ungaged streams in Maine: U.S. Geological Survey Scientific

InvestigationsReport 2020–5092, 56 p.

(https://doi.org/10.3133/sir20205092)Percentage of land underlain

It is critical that water be controlled during construction, both allowing free flow of the stream through the site, and eliminating potential sedimentation and erosion. Any fish must thoroughly and carefully be removed and excluded from the work site before in-stream work begins (including properly screening pump intakes). All Maine Department of

Environmental Protection Best Management Practices for Sediment and Erosion Control should be followed. The existing culvert cannot be left in place during the construction process since the crossing is being decommissioned. Sandbag cofferdams must be placed to control stream flow for pumping around the site. Dirty water must be removed from the work site and filtered in nearby forest to avoid contamination of the stream. Sufficient pump capacity and length of discharge hoses are essential to maintain water control, with backup pumps on hand or readily available. Refer to the map below for likely placement of water control elements.

Removal of existing culvert Dirty water pumped from work site Dirty water filtered in nearby forest

Rock for scour protection and bed features: While some rock should be able to be found on site, the following total volumes must be available:

12-18" sub-angular bank rock @ ≈ 2-3 yards 6-12" rounded rock for stream bed armoring @ ≈ 5 yards

Sandbags for Cofferdams: 30 small, preferrably poly bagged Polyethylene Sheeting (6 mil - for cofferdam sealing as needed)

Pump conveys streamflow

Dirty Water Pump

Clean Water Pump

Block Net

Block Net

Filtration Basins

BM1 - ≈ 60' NW from crossing center BM2 - ≈ 40' E from crossing center BM3 - ≈ 50' SW from crossing center

Yellow-capped Rebar at base of maple Magnetic Nail in base of double birch Magnetic nail in base of spruce

Three "temporary" benchmarks were set at the time of survey in 2015, and their location may be difficult to determine given the passage of time and the likelihood that the (pink) flagging used to mark them may have been degraded beyond recognition. The photos below should help to determine their locations, along with the topographic map images above.

Attachment 4

Site Map - Drainage Area Crossing

Notes:

This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

0.6% Slope

Existing 3' diameter culvert

CrossSection

Wassataquoik Stream

Cross Section

Cross Section 1 - Upstream of Crossing

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Bankfull Width

Bankfull Width: 3.5'

Bankfull Depth: 0.75'

Bankfull XS Area: 2.5 ft2

Substrate: 2' or more of aggraded fines with some gravel

Cross Section 2 - Downstream (Tailwater Control) of Crossing

Notes: This cross-section is not meant as an ideal reference for crossing design.

This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Bankfull Width Bankfull Width: 5.8'

Bankfull Depth: 0.25'

Bankfull XS Area: 1.45 ft2

Substrate:

Gravel/Cobble

Permanent Fill = 50 sq. ft.

Temporary Fill = 80 sq. ft.

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Aggraded material to be partially removed and to erode over time

Overall Restoration Reach Slope = 2.5 %

Existing Stream Bed

Expected Stream Bed

Wassataquoik Stream

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Existing 3' Culvert

7 ft2

6' Bankfull Width

Elevation

657'

Bank Foundation

Rock

NW/Left Bank SE/Right Bank

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Banklines are composed of 6 - 12 inch (average intermediate dimension – not longest or shortest measure) competent, angular to sub-angular foundation rock. Banklines must connect to the natural stream banks to provide a relatively seemless connection to the floodplain. Additional smaller rock is also necessary for filling gaps in the larger material to provde more stable banklines.

"Inlet" Elevation

656.8'

Flow

Plan View

Bank Armor Rocks

Existing Stream Bed

Expected Stream Bed

HY-8 Hydraulic Analysis Program of the U.S. Federal Highway Administration provides results for the above peak flow estimates for the proposed arch design, and indicates that the restored crossing area as proposed will easily pass the expected 1% AEP flow/ storm event.

Note that prediction errors are quite large when using regression equations to estimate flows and bankfull widths based on drainage area. It is best to account for potentially larger flows at these return intervals.

Attribute Value Units Definition References:

Drainage Area 0.16 sq. miles Area that drains to crossing 99 8

Wetlands 3.8 percent Percentage of NWI storage 50 13

Elevation 800 feet Mean basin elevation 20 23

Precipitation 45.6 inches Mean annual precipitation 10 30

Aquifer Unknown percent 4 40

2 49

X-coordinate 514492 State Plane m Basin centroid E/W location 1 58

Y-coordinate 5097741 State Plane m Basin centroid N/S location 0.2 82

Return

Probability (%)

Peak QT

(ft3/s)1

1 Lombard, P.J., and Hodgkins, G.A.,2020, Estimating flood magnitude and frequency ongaged and ungaged streams in Maine: U.S. Geological Survey Scientific

InvestigationsReport 2020–5092, 56 p.

(https://doi.org/10.3133/sir20205092)Percentage of land underlain

AEP

Total Discharge

(cfs)

Headwater Elevation

(ft)

Flow Type

Outlet Depth

(ft)

Outlet Velocity

(ft/s) 99 8.00 657.73 7-H2t 0.59 3.56

50 13.00 658.00 7-H2c 0.74 4.21

20 23.00 658.34 7-JH2c 1.20 2.98

10 30.00 658.34 7-H2c 1.26 3.19

4 40.00 658.45 7-H2c 1.33 3.49

2 49.00 658.55 7-H2c 1.38 3.72

1 58.00 658.63 7-H2t 1.45 3.76

0.2 82.00 658.86 7-H2t 1.73 3.37

It is critical that water be controlled during construction, both allowing free flow of the stream through the site, and eliminating potential sedimentation and erosion. Any fish must thoroughly and carefully be removed and excluded from the work site before in-stream work begins (including properly screening pump intakes). All Maine Department of

Environmental Protection Best Management Practices for Sediment and Erosion Control should be followed. The existing culvert cannot be left in place during the construction process since the crossing is being decommissioned. Sandbag cofferdams must be placed to control stream flow for pumping around the site. Dirty water must be removed from the work site and filtered in nearby forest to avoid contamination of the stream. Sufficient pump capacity and length of discharge hoses are essential to maintain water control, with backup pumps on hand or readily available. Refer to the map below for likely placement of water control elements.

Removal of existing culvert Dirty water pumped from work site Dirty water filtered in nearby forest

Rock for scour protection and bed features: All materials should be able to be found on site

Sandbags for Cofferdams: 20 small, preferrably poly bagged Polyethylene Sheeting (6 mil - for cofferdam sealing as needed) 2" Trash pump for dirty water extraction and filtration - 10-15' screened intake hose, 150' of discharge hose 3" Pump for fresh water bypass - 10-15' screened intake hose, 150' of discharge hose

Pump conveys streamflow

Dirty Water Pump

Clean Water Pump

Block Net

Block Net

Filtration Basins

Cofferdam

Fill Information:

Permanent Fill = 50 sq. ft.

Temporary Fill = 80 sq. ft.

BM1 - ≈ 35' WNW from crossing center BM2 - ≈ 45' NW from crossing center BM3 - ≈ 20' SSE from crossing center

Yellow-capped Rebar at base of maple Magnetic Nail in base of maple Magnetic nail in base of red pine

Three "temporary" benchmarks were set at the time of survey in 2015, and their location may be difficult to determine given the passage of time and the likelihood that the (pink) flagging used to mark them may have been degraded beyond recognition. The photos below should help to determine their

Attachment 5

Site Map - Drainage Area Crossing

Notes:

This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Existing 6' diameter culvert

Cross Section

Aggraded

Wassataquoik Stream

Cross Section 2 Cross Section

Wood

Aggraded

Cross Section 1 - Upstream of Crossing

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Bankfull Width

Bankfull Width: 10.7' Bankfull Max Depth: 0.8' Bankfull XS Area: 7.2 sq ft

Substrate

Cross Section 3 - Downstream of Crossing

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Bankfull Width

Substrate Distribution:

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0%

2%

4%

6%

8%

10%

12%

14%

16%

18%

20%

22%

24%

26%

28%

30%

C u m u la ti ve P e rc e n t

Paricle Size (mm)

P e rc e n t o f

T o ta l P e r

B in

Si ze R a n ge

Cumulative Percent Percent of Total Per Bin d98 = 336.1 mm d84 = 163.5 mm d50 = 83.5 mm

Bankfull Width: 8.9' Bankfull Max Depth: 1.1' Bankfull XS Area: 12 sq ft

Permanent Fill = 50 sq. ft.

Temporary Fill = 100 sq. ft.

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Removed Culvert

Aggraded material to be partially removed and to erode over time

Overall Restoration Reach Slope ≈ 3 %

Existing Stream Bed

Expected Stream Bed

Wassataquoik Stream

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Existing 6' Culvert

28 ft2

11' Bankfull Width

Elevation

647'

Bank Foundation Rock & Stepping Stones

NW/Left Bank SE/Right Bank

Note: This view is vertically exaggerated, reflecting the different scales of units for elevation and distance.

Banklines are composed of 12 - 18 inch (average intermediate dimension – not longest or shortest measure) competent, angular to sub-angular foundation rock.

Banklines must connect to the natural stream banks to provide a relatively seemless connection to the floodplain. Additional smaller rock is also necessary for filling gaps in the larger material to provde more stable banklines.

Stepping stones are flat on top, larger than most bank rocks, and placed to assist pedestrians in crossing the stream.

"Inlet" Elevation

647'

Flow

Plan View

Removed Aggraded Sediments

Bank Armor Rocks

Existing Stream Bed

Expected Stream Bed

Overall Restoration Reach Slope ≈ 3 %

Stepping Stones

HY-8 Hydraulic Analysis Program of the U.S. Federal Highway Administration provides results for the above peak flow estimates for the proposed arch design, and indicates that the

Note that prediction errors are quite large when using regression equations to estimate flows and bankfull widths based on drainage area. It is best to

Total Discharge

(cfs)

Headwater Elevation

(ft)

Flow Type

Outlet Depth

(ft)

Outlet Velocity

(ft/s) 99 20.00 648.08 1-S2n 0.56 5.79

50 34.00 648.48 1-S2n 0.71 6.89

20 56.00 648.65 1-S2n 1.00 7.00

10 72.00 648.79 1-S2n 1.22 5.83

4 95.00 648.97 1-S2n 1.29 6.46

2 113.00 649.09 1-S2n 1.35 6.83

1 133.00 649.23 1-S2n 1.40 7.18

0.2 184.00 648.59 1-S2n 1.53 7.88 649.59

No Fill - For Model Purposes Only

Attribute Value Units Definition References:

Drainage Area 0.58 sq. miles Area that drains to crossing 99 20

Wetlands 7 percent Percentage of NWI storage 50 34

Elevation 800 feet Mean basin elevation 20 56

Precipitation 45.6 inches Mean annual precipitation 10 72

Aquifer 5 percent 4 95

2 113

X-coordinate 519577 State Plane m Basin centroid E/W location 1 133

Y-coordinate 5087445 State Plane m Basin centroid N/S location 0.2 184

Return

Probability (%)

Peak QT

(ft3/s)1

1 Lombard, P.J., and Hodgkins, G.A.,2020, Estimating flood magnitude and frequency ongaged and ungaged streams in Maine: U.S. Geological Survey Scientific

InvestigationsReport 2020–5092, 56 p.

(https://doi.org/10.3133/sir20205092)Percentage of land underlain

It is critical that water be controlled during construction, both allowing free flow of the stream through the site, and eliminating potential sedimentation and erosion. Any fish must thoroughly and carefully be removed and excluded from the work site before in-stream work begins (including properly screening pump intakes). All Maine Department of Environmental Protection Best Management Practices for Sediment and Erosion Control should be followed. The existing culvert cannot be left in place during the construction process since the crossing is being decommissioned. Sandbag cofferdams must be placed to control stream flow for pumping around the site. Dirty water must be removed from the work site and filtered in nearby forest to avoid contamination of the stream. Sufficient pump capacity and length of discharge hoses are essential to maintain water control, with backup pumps on hand or readily available. Refer to the map below for likely placement of water control elements.

Removal of existing culvert Dirty water pumped from work site Dirty water filtered in nearby forest

Rock for scour protection and bed features: All materials should be able to be found on site

Sandbags for Cofferdams: 40 small, preferrably poly bagged Polyethylene Sheeting (6 mil - for cofferdam sealing as needed) 2" Trash pump for dirty water extraction and filtration - 10-15' screened intake hose, 150' of discharge hose 3" Pump for fresh water bypass - 10-15' screened intake hose, 150' of discharge hose

Pump conveys streamflow

Dirty Water Pump

Clean Water Pump

Block Net

Block Net

Filtration Basins

BM1 - ≈ 45' SE from crossing center BM2 - ≈ 45' N from crossing center BM3 - ≈ 35' SW from crossing center

Yellow-capped Rebar at base of white pine Magnetic Nail in base of birch Magnetic nail in base of birch (US/RR)

(DS/RR/Road Edge) (DS/RL/Road Edge)

Three "temporary" benchmarks were set at the time of survey in 2015, and their location may be difficult to determine given the passage of time and the likelihood that the (pink) flagging used to mark them may have been degraded beyond recognition. The photos below should help to determine their