24-08-35 PLANS-Narrows Lane Final Design Stream Restoration.pdf

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STREAM RESTORATION DESIGN

CITY SW PLAN #1038.2

CITY PLANNING #CP23-0002

MARCH 22, 2023

Wetland Studies and Solutions, Inc.R companyaDAVEY R

5450 Peters Creek Road • Suite 110 Roanoke, Virginia 24019

Phone: 540-795-6180 www.wetlands.com

OH UTILITY LINE

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PARCEL BOUNDARIES

EX. CONTOURS (1' C.I.)

EX. SANITARY

EX. STORM DRAINAGE

EX. WATER LINE

EX. EDGE OF PAVEMENT

EX. DITCH

EX. OVERHEAD TELEPHONE LINE

EX. GAS LINE

EX OVERHEAD UTILITIES

EX OVERHEAD ELECTRIC

EX , UG TELEPHONE

BNDRY 2015 TOPO. (SUPPLEMENTED

WITH ADDITIONAL SHOTS)

EX. GUARD RAIL

NEW (2022) WSSI SURVEYED TOPO.

EX. STORMWATER EASEMENTS

EX. RIPRAP

EX. TREELINE

EX. CHAINLINK FENCE

WATER METER, WATER MANHOLE,

HYDRANT, GAS VALVE, MAIL BOX

BUSH, DECIDUOUS TREE, TREE TO BE

REMOVED (SCALED BY SIZE)

FOUND IRON ROD PROPERTY MARKER

EXISTING CONDITIONS LEGEND

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SURVEY NOTES:

1. This existing conditions survey has been horizontally oriented to The Virginia Coordinate System of 1983, South Zone, and vertically referenced to the North American Vertical Datum of 1988 (NAVD88) by field locations of monumentation shown on this drawing provided by The City of Roanoke - Stormwater Division. Wetland Studies and Solutions, Inc. (WSSI) used a Real Time Network (RTN) GPS to field verify the coordinate systems. Horizontal and vertical data is expressed in U.S. Survey Feet. Field locations of the supplemental existing conditions were completed on 08/16/2022.

2. The majority of survey data was collected by WW Associates in 2015 and provided to WSSI by the City of Roanoke. This included property information, utility infrastructure, 2-foot contour interval topography, roadways, and isolated tree locations.

WSSI performed a supplemental existing conditions site survey to augment existing 2-foot contour interval topography and utility survey information. The supplemental data will be used to aid in the proposed stream restoration design.

3. The methodology required and requested for this survey precludes the depiction of all physical improvements, man-made structures and underground features.

4. Contour interval = 1.0 feet

SUPPLEMENTAL TOPO

COLLECTED BY WSSI,

JULY 2022

SUPPLEMENTAL TOPO

COLLECTED BY WSSI,

JULY 2022

VAN WINKLE ROAD

EXISTING STORMWATER

EASEMENTS 15 FT

OFFSET FROM

PROPERTY LINES

APPROXIMATE

LOCATION OF

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Design Narrative I. Background

The Narrows Lane drainage improvement and channel restoration project is located between Old Rocky Mountain Road and Narrows Lane SW east of Route 220. The project begins at the existing roadside ditch/driveway culvert on 4521 Narrows Lane and continues downstream for approximately 700 linear feet before entering into the existing 5-ft diameter road culvert under Narrows Lane near the intersection with Old Rocky Mount Road.

The project is designed to address erosion seen along the south side of the Narrows Lane right-of-way, and includes improvements to storm drain infrastructure along Narrows Lane to address minor flooding associated with driveway culverts. The upstream portion of the project area will remove existing driveway culverts and install approximately 200 linear feet of continuous culvert along the edge of the right-of-way to reduce flooding associated with constrictions and blockages at individual driveway culverts. Additional modifications to the storm drainage network will be necessary to eliminate discontinuous piped channel areas and allow for improved outlet configurations for two (2) storm drainage pipes conveying flow into the project area from the north side of Narrows Lane near the intersection with Van Winkle Road.

Overall topography for the design reach is gently to moderately sloping, with steeper areas associated with the adjacent roadway embankment. The project area encompasses much of the confined floodplain area, bounded tightly by Old Rocky Mount Road and Narrows Lane. Channel slope varies widely, from 1% at the upstream and downstream tie-outs, to 5% in limited areas within the project reach.

II. Preliminary Hydrologic Analysis

A total drainage area for the upstream project boundary of approximately 65 acres was determined by Lumsden Associates, P.C. as part of a 2021 “Channel Analysis Calculations” report prepared for Rockydale Quarries and provided to WSSI by City staff (figure 4, next page).

Hydrologic computations for the upper drainage area were based on the Rational Method, utilizing AutoCAD Civil 3D 2009 Hydraflow Hydrographs extension. Peak flows were computed for the 2- and 10-yr recurrence interval SCS Type II storm, with flows of 75 cfs and 102 cfs, respectively. Additional drainage from along Narrows Lane and Van Winkle Road enters the project reach through two (2) existing 24-in culverts under Narrows Lane, adding an estimated 50 acres of contributing drainage area when taken to the downstream end of the design reach.

The previous hydrologic analysis for the upstream drainage area (65 acres) was supplemented by consideration of the published USGS Non-Urban Regional Curves for the Valley and Ridge Physiographic Province of Virginia (Figure 1). These curves were developed to predict bankfull characteristics for streams with low watershed imperviousness (typically less than 5%) and should be adjusted to consider development in the project watershed. This may be achieved through application of an urban channel enlargement factor. The Center for Watershed Protection published a report on the impact of watershed development on channel enlargement. From this study, it is estimated that ultimate channel enlargement can take 50-75 yrs or longer from the time the watershed is fully developed. A plot depicting the ultimate channel size vs. watershed impervious area is presented in the article and given as Figure 2. The imperviousness in the Narrows Lane watershed (conservatively estimated at 20% for the 115 ac drainage) yields a resulting enlargement factor of approximately 2.0.

Bankfull Channel Geometry as Predicted by the Valley and Ridge Non-Urban Regional Curves:

(For an estimated 115-acre or 0.179 mile drainage area)

Cross-sectional Area = 3.6 sf Bankfull Width = 5.9 ft

Bankfull Flow = 11.04 cfs

III. Channel Sizing To accommodate the expected discharge from the upstream developed and piped watershed the channel was sized using a discharge of 22 cfs, which yielded a channel with a width of 12 ft and depth of 1.2 ft (at a slope of 2%). This yielded a channel with a cross section of

9.36 square feet. While this cross section is slightly larger than that predicted by the Valley and Ridge Regional Curve with an enlargement factor (3.6 sf x 2 EF = 7.2), the additional size allows for added drainage from Tributaries 1 and 2 and a factor of safety when considering the atypical watershed condition (large quarry with pumped discharge). Appropriate dimensions were determined by iteratively solving Manning's open channel flow equation with various geometric configurations.

IV. Discussion of Design Alternatives and Design Narrative When considering the Narrows Lane design reach in the context of Rosgen's channel classification system, the channel exhibits characteristics of a B-type (moderately entrenched, confined valley). The existing channel shows signs of downcutting and ongoing bank erosion. It is anticipated that as the channel evolves the stream will widen to reform a floodplain within the widened entrenched channel.

Left unchecked, the design reach is likely to see continued erosion as the stream widens, impacting the adjacent roadway and potentially the 8" sanitary sewer passing under the stream.

Implementation of a Priority 1 (P1) restoration (Figure 3) would involve reconstructing the stream channel with a size appropriate for the current and predicted watershed conditions, but at an elevation which allows better connection with the adjacent floodplain. A P1 restoration provides the highest degree of channel stability and ecological benefit while limiting disturbance to the existing floodplain corridor. This design option can result in adverse effects on adjacent infrastructure due to elevated floodplain flows. This is not a major concern on this site, as structures previously affected by nuisance flooding have been razed. This approach typically involves significant quantities of fill and/or excavation and installation of grade control structures to establish a stable channel pattern and profile.

A Priority 2 (P2) restoration involves excavation of floodplain material in order to create a bankfull floodplain at a lower elevation where good floodplain connectivity is not otherwise seen. This approach often involves major excavation and haul off, as well as significant disturbance to the surrounding riparian vegetation/trees. Project costs for this strategy can approach those of a P1 design.

A Priority 3 restoration involves the creation of a limited bankfull bench and isolated bank grading to reduce shear stresses and bank erosion. This approach does not seek to achieve long-term stability for the entire reach, but rather focuses resources on areas of highest erosion, thus presenting a more cost-sensitive alternative. However, this strategy is inconsistent with stated project goals and is not applicable on this site.

The goals of this project necessitate use of a design strategy that achieves long-term stability, improves floodplain connectivity to maximize water quality benefits, and enhances stream habitat. Design channel size is based natural channel design principles, with application of the USGS regional curves with an urban channel enlargement factor applied. When sizing the channel, WSSI engineers compared regional curves against flow rates from the Lumsden hydrologic analysis (2021). Based on previous experience with small headwater streams, WSSI has found that traditional hydrologic approaches tend to significantly overestimate flows. Thus, the 75 cfs flow predicted for the 2-yr recurrence interval storm through application of the rational method was considered an upper bound for the design flow. Conversely, strict application of the USGS regional curves without acknowledging watershed development may result in an undersized channel and floodplain scour/instability. WSSI chose to size the channel using Mannings' open channel flow equation based on the adjusted regional curves. Lower slopes in the upper portion of the reach will help to slow velocities exiting the stormwater pipe, while encouraging floodplain access. As the channel profile steepens mid-way through the reach, conveyance capacity increases, while further flow contributions from additional outfalls along Narrows Lane increase the contributing drainage area. The selected design utilizes natural channel design principles to create a channel that is well connected to the surrounding floodplain, yet large enough to promote riparian corridor stability.This channel sizing approach is consistent with the stated design goals of long-term stability and strong floodplain connectivity. Long term stability was confirmed via hydraulic modeling in HEC-RAS, which indicated that overbank velocities in the 2-year (75 cfs) and 10-year storms (102 cfs) do not exceed 2 feet per second (flows from Lumsden study).

The design profile incorporates a degree of channel reconnection (elevating the invert above the currently incised channel), while increasing planform sinuosity, hence it most resembles a priority 1 restoration. These planform adjustments will shift the channel away from Narrows Lane, enhance floodplain connectivity, and allow for stronger pool formation. This approach utilizes various rock and wood grade control structures to maintain a stable planform geometry and profile, while limiting channel erosion through incorporation of an appropriately sized reinforced bed material. Likewise additional channel stability will be afforded via native riparian plantings (including black willow live stakes at the stream edge). These plantings will also provide stream shading and enhance nutrient uptake.

Figure 1. Non-Urban Valley and Ridge Regional Curves for Select Geomorphic Parameters in Maryland, Virginia, and West Virginia

Adapted from: Keaton, Messinger, and Doheny. 2005, Development and Analysis of Regional Curves for Streams in the Non-Urban Valley and Ridge Physiographic Province, Maryland, Virginia, and West Virginia. U.S. Geological Survey Scientific Investigations Report 2005–5076, p. 14-15.

"Ultimate" Channel Enlargement as a Function of Impervious Cover in Alluvial Streams in Maryland, Vermont and Texas (MacRae and DeAndrea, 1999; Brown and Claytor, 2000)

Figure 2. Urban Channel Enlargement Factor

Figure 3. Stream Restoration Design Priority

V. Floodplain Analysis

The proposed design reach does not lie within a FEMA-mapped floodplain and is contained solely within City-owned property.

Thus, formal floodplain modeling was not performed.

Source: Wetland Studies and Solutions, Inc. Graphic

Priority 1 Restoration - Raise and Reconnect to Floodplain

Width of Disturbance

Balanced cut/fill

Lesser Tree Impacts

Priority 2 Restoration - Excavate Floodplain at Lower Elevation

Width of Disturbance

High Cut Volume

Increased Impacts to Existing Riparian Corridor

Priority 3 Restoration - Bankfull Bench (Confined Valley)

Bankfull Bench Limited Disturbance

-Limited Disturbance, higher post-restoration stress, lower ecological lift

DA=0.179 SQ MI

UNADJUSTED

CSA= 3.64 SQ FT

DA=0.179 SQ MI

UNADJUSTED

W= 5.88 FT

DA=0.179 SQ MI

UNADJUSTED

Q= 11.04 CFS

20% IMPERVIOUSNESS

ASSUMED

ENLARGED CSA = 7.2 SQ FT

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APPROXIMATE DRAINAGE AREA TO DOWNSTREAM PROJECT BOUNDARY

(DELINEATION INFORMATION PROVIDED BY CITY STAFF)

SEQUENCE OF CONSTRUCTION

1. NO IN-STREAM WORK SHALL BEGIN UNTIL ALL E&S CONTROLS HAVE BEEN PROPERLY INSTALLED (PERIMETER SILT FENCE AND CONSTRUCTION ENTRANCES, ETC.; SEE E&S PLAN FOR INFORMATION REGARDING PRE CONSTRUCTION MEETING) AND THE SPECIFIED STABILIZATION SEED MIXES AND NATURAL FIBER EROSION CONTROL MATTING ARE ON SITE. ADDITIONALLY, STREAM CENTERLINE AND LIMITS OF DISTURBANCE SHALL BE SURVEYED AND STAKED-OUT PRIOR TO BEGINNING OF WORK.

2. INITIAL SITE ACCESS AND MOBILIZATION SHALL BE FROM NARROWS LANE. SEE SHEET 06.

3. ACCESS WITHIN THE STREAM CORRIDOR SHALL BE VIA THE SOUTH SIDE OF THE STREAM, ALONG THE

PROPOSED ALIGNMENT. SITE ACCESS WILL BE GAINED ACROSS THE EXISTING CULVERT.

4. WORK SHALL PROGRESS FROM DOWNSTREAM TO UPSTREAM (UNLESS OTHERWISE AUTHORIZED BY CITY STAFF), TO ALLOW FOR UTILIZATION OF THE PROPOSED CHANNEL CORRIDOR AS AN ACCESS

PATH.

5. ALL WORK SHALL OCCUR IN THE DRY. THE CONTRACTOR SHALL WORK TO CONSTRUCT THE

PROPOSED CHANNEL WHILE ALLOWING FLOW TO CONTINUE THROUGH THE UNDISTURBED EXISTING

DITCH LINE. WHERE PROPOSED AND EXISTING CHANNELS OVERLAP, WORK AREAS SHALL BE

PROTECTED BY A PUMP AROUND DIVERSION.

6. THE CONTRACTOR SHALL BEGIN BY CUTTING ONLY THOSE TREES NECESSARY FOR PROPOSED

GRADING AS INDICATED ON SHEET 16. ANY TREES NOT INDICATED TO BE REMOVED THAT ARE 6" + IN

DIAMETER SHALL BE APPROVED BY OWNER PRIOR TO REMOVAL.TREES SHOULD BE FELLED SUCH

THAT DAMAGE TO SURROUNDING TREES IS MINIMIZED. IN AREAS WHERE GRADING IS NOT REQUIRED BUT TREES ARE SIGNIFICANTLY IMPACTED, TREES SHOULD BE FLUSH CUT AND THE ROOT BALL LEFT

IN PLACE. LOGS SHALL BE CAREFULLY STOCKPILED DURING CLEARING.

7. ONCE TREES HAVE BEEN REMOVED THE CONTRACTOR SHALL BEGIN BY WORKING ON DOWNSTREAM AREAS, GRADING BANKS BACK AS INDICATED WHILE MINIMIZING DISTURBANCE TO ACCESS AREAS WHEN ADJACENT TO MATURE TREES TO BE LEFT UNDISTURBED. DECK MATS SHALL BE USED NEAR

TREES AND AS NECESSARY TO PREVENT RUTTING IN WET AREAS.

8. FINAL GRADES SHALL BE ACHIEVED THROUGH THE PLACEMENT OF 4 INCHES OF TOPSOIL (SALVAGED OR IMPORTED, SEE SPECIFICATIONS FOR TOPSOIL SALVAGING AND STOCKPILING PROCEDURE). THE

CONTRACTOR SHALL ONLY CLEAR AND GRUB AS MUCH OF THE PROPOSED CHANNEL AND

GRADING AREAS THAT THE CONTRACTOR CAN COMPLETE THE CONSTRUCTION ON AND HAVE

STABILIZED IN THE SAME DAY AS THE CLEARING AND GRUBBING. WHERE SOILS HAVE BEEN

COMPACTED BY CONSTRUCTION TRAFFIC THE CONTRACTOR SHALL SCARIFY SUBGRADE PRIOR TO

TOPSOIL PLACEMENT TO PROMOTE GOOD VEGETATIVE ESTABLISHMENT.

9. CONTRACTOR SHALL WORK PROGRESSIVELY, FINISH GRADING, SPREADING NATIVE SEED, AND

INSTALLING MATTING ALONG PROPOSED CHANNEL AREAS IMMEDIATELY UPON ACHIEVING FINAL

GRADE. THIS WILL MINIMIZE THE AMOUNT OF DISTURBED AREA IN THE EVENT OF A HIGH FLOW EVENT.

10. ALL DISTURBED AREAS SHALL BE SEEDED WITH RIPARIAN SEED MIX UNLESS OTHERWISE SPECIFIED IN THE PLANTING PLAN. NATURAL FIBER MATTING SHALL BE PLACED PER THE TYPICAL RIFFLE DETAIL AND AS OTHERWISE INDICATED IN THE PLAN, STAKED TO MANUFACTURERS SPECIFICATIONS USING

BIODEGRADABLE STAKES. (NOTE: SEED MUST BE SOWN IMMEDIATELY PRIOR TO MATTING

PLACEMENT.)

11. ONCE ALL PROPOSED GRADING IS COMPLETE THE CONTRACTOR SHALL RESTORE UNLESS

OTHERWISE INDICATED BY PLANS ALL STAGING/STOCKPILE AND ACCESS AREAS TO PRE-EXISTING CONDITIONS USING THE APPROPRIATE SEED MIX WHERE INDICATED AS WELL AS STRAW MULCH OR

MATTING PER LOCAL REQUIREMENTS AND THE VIRGINIA E&S HANDBOOK.

12. PLANTINGS SHALL BE INSTALLED PER THE PLANTING PLAN AND SPECIFICATIONS AND ADHERING TO

THE SPECIFIED TIME OF YEAR PLANTING WINDOWS.

13. THE CONTRACTOR SHALL ASSESS THE POST-CONSTRUCTION CONDITIONS OF EXISTING

INFRASTRUCTURE, REPAIRING ANY DAMAGE NOT OTHERWISE SPECIFIED IN THESE PLANS TO

PRE-EXISTING CONDITIONS OR BETTER.

14. CONTRACTOR SHALL REMOVE E&S MEASURES AND RETURN ANY REMAINING DISTURBED AREAS TO A

PRE-CONSTRUCTION CONDITION.

15. CONTRACTOR TO FOLLOW ALL APPLICABLE OSHA REQUIREMENTS.

APPROX.

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Utilization of Fine Particles

The shear stress computations presented on this sheet represent the force required to initiate movement of non-imbricated particles. The reinforced bed mix used in this project shall have fine-grained particles (i.e.

gravel, sand, and topsoil) mixed with the “armor” material to fill the void spaces in the rocks (see the reinforced bed mixture specifications on the Design Narrative sheet). The mixing of the fine grain substrate material with the armor rock will promote imbrication, further enhancing the reinforced bed material stability. In addition to providing enhanced stability, this smaller substrate material will encourage water to flow along the surface of the stream bed as it would in a naturally occurring stream system. Without fines flow would be primarily subsurface until natural detritus buildup could replace the smaller particle size fractions. Further, the variety of substrate particle sizes will increase species diversity by providing aquatic macroinvertebrates, fish, and amphibians with a larger number of niches to colonize. Finally, the smaller bed material fractions will improve the aesthetic properties of the restored stream by allowing "sorting" to occur during the significant flow events following construction. Smaller particles may move out of the riffles and deposit on or form point bars (and other depositional features) and/or deposit in pools. The result is a variety of stream facets and natural gradation of particle sizes created by varying energy environments of the stream system. This creates a more natural appearance than could be practicably graded during construction.

STEP 2: CONSERVATIVE ESTIMATE OF STABLE "ARMOR"

ROCK (CALCULATE THE BOUNDARY SHEAR

STRESS USING THE MAXIMUM RIFFLE DEPTH)An analysis of shear stress is necessary to understand bed mobility. To achieve the desired threshold condition, the size (D50) of the large rock (“armor”) portion of the reinforced bed mix is determined by first calculating the "mean depth" boundary shear stress (i.e. Shield's Equation) for the proposed channel using the hydraulic radius (approximately the mean depth, Equation 1). The "mean depth" boundary shear stress value is then inserted into a regression equation developed by Rosgen (2006) using data from Leopold et. al. (1964) to determine the particle size D50 needed to achieve a stable stream bed (Equation 2). A Factor of Safety greater than or equal to 1.3 is desired and is based on the ratio of the computed rock size versus provided rock size (Equation 3). As a check, the above process is repeated using the "maximum" boundary shear stress (Equation 4). The term “maximum” boundary shear stress is used because typically, boundary shear stress calculations are performed using the hydraulic radius (approximately the mean riffle depth, refer to Equations 1 and 2). Using the "maximum" boundary shear stress as a check of the initial calculation provides a conservative estimate of the required D50 for the "armor" rock. For this conservative estimate, a Factor of Safety greater than or equal to 1.0 is desired and is based on the ratio of the computed rock size versus provided rock size (Equation 6). Calculations are presented for a range of riffle slopes used in the Narrows Lane restoration design.

STEP 1: "ARMOR" SIZE DETERMINATION

Based on the calculations herein (at right), the D50 particle size needed to achieve a stable stream channel for the Narrows Lane stream restoration project is 1.4, 5.1, and 8.3 inches, for the minimum, average, and maximum riffle slopes in this design, respectively. This indicates bed mobility in areas not founded on bedrock and highlights the potential for continued and severe bank erosion. These calculations show the need for import of an appropriately sized reinforced bed mixture, one which will resist erosion while riparian vegetation is reestablished on channel banks. Class 1 rock (D50 = 13.2 in) exceeds the target Factor of Safety and is therefore of sufficient size to be used as the stable armor component in the reinforced bed mixture. The reinforced bed mixture shall be prepared as specified in the Reinforced Bed Mixture Specifications provided in the construction details sheets (Sheet 11).

SEDIMENT SIZING CALCULATIONS

Literature Cited

Leopold, Luna B., Wolman, Gordon M., and Miller, John P. Fluvial Processes In Geomorphology. Dover Publications, New York, 169 - 172, 1964.

Maidment, David R., ed. Handbook of Hydrology. McGraw-Hill, Washington D.C., 12.16 - 12.20, 1993.

Rosgen, Dave. Watershed Assessment of River Stability and Sediment Supply (WARSSS). Wildland Hydrology, Fort Collins, 5-129 - 5-136, 2006.

SECTION OF 5.5% SLOPE IS BOUNDED ON

UPSTREAM AND DOWNSTREAM END BY

GRADE CONTROL STRUCTURES,

SIGNIFICANT EROSION NOT ANTICIPATED.

±16.5' CLEARANCE

LATERAL SEWER LINE

PARCEL BOUNDARIES

EX. CONTOURS (1' C.I.)

EX. SANITARY

EX. STORM DRAINAGE

EX. WATER LINE

EX. EDGE OF PAVEMENT

EX. DITCH

EX. OVERHEAD TELEPHONE LINE

EX. GAS LINE

EX OVERHEAD UTILITIES

EX OVERHEAD ELECTRIC

EX , UG TELEPHONE

BNDRY 2015 TOPO. (SUPPLEMENTED

WITH ADDITIONAL SHOTS)

EX. GUARD RAIL

NEW (2022) WSSI SURVEYED TOPO.

EX. STORMWATER EASEMENTS

EX. RIPRAP

EX. TREELINE

EX. CHAINLINK FENCE

WATER METER, WATER MANHOLE,

HYDRANT, GAS VALVE, MAIL BOX

BUSH, DECIDUOUS TREE, TREE TO BE

REMOVED (SCALED BY SIZE)

FOUND IRON ROD PROPERTY MARKER

EXISTING CONDITIONS LEGEND

PROPOSED GRADING (1' C.I.)

TEMPORARY STOCKPILE

CONSTRUCTION ENTRANCE

LIMIT OF DISTURBANCE

BOULDER POOL WITH

DOWNSTREAM ROCK SILL

PROPOSED CENTERLINE

PROPOSED BANKFULL

IN-STREAM HABITAT LOG SILL

GRADING LEGEND

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WSSI and Roanoke City Digital Data

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STONE CONSTRUCTION ENTRANCE

TO REMAIN IN PLACE AS

MAINTENANCE ACCESS.

CLASS II OUTLET PROTECTION

TOP-DRESSED WITH

SALVAGED BED MATERIAL

~17 LF OF IMBRICATED ROCK WALL

AT 0.5:1 SLOPE (MAX). MAX WALL

HEIGHT OF 42". CONTRACTOR TO

COORDINATE EXACT WALL

PLACEMENT WITH CITY PROJECT

ENGINEER

LOG VANE WITH

ROCK SILL

PROPOSED PIPE INVERT

OUT = 1253.65', STA.

12+35.56' (OUTFALL 1)

GRADING NOTES

1. PROPOSED CONTOURS ARE INTENDED TO DEPICT OVERALL GRADING CONCEPT. DUE TO IRREGULARITY OF ROCK SHAPES, CONTOURS DEPICTING POOL GRADING WITHIN STRUCTURES ARE APPROXIMATE. SPECIFICATIONS FOR GRADING IN VICINITY OF STRUCTURES ARE PROVIDED IN TYPICAL SECTIONS AND CONSTRUCTION DETAILS. THE SPECIFICATIONS IN THE CONSTRUCTION DETAILS TAKE PRECEDENCE OVER THE CONTOURS DEPICTED ON THE

GRADING PLAN.

2. ALL STREAM BEDS REQUIRE 18" OF CLASS I REINFORCED BED MATERIAL EXCEPT WHERE OTHERWISE NOTED. FOR CLARITY, IT IS NOT SHOWN IN THE PLAN VIEW WHERE GRADING IS DEPICTED. FOR ADDITIONAL DETAILS ON

REINFORCED BED MATERIAL PLACEMENT REFER TO THE PROFILE AND DETAILS.

3. ALL PLACED FILL MATERIAL AND REINFORCED BED MATERIAL SHALL BE COMPACTED WITH THE TRACK HOE BUCKET OR TRACKED IN TO A REASONABLE COMPACTION (85% COMPACTION). CITY PROJECT MANAGER MAY REQUEST THE

USE OF TRENCH ROLLER COMPACTION EQUIPMENT FOR THE PLACEMENT OF FILL.

4. FOLLOWING CONSTRUCTION, ALL GRADES (OUTSIDE OF SPECIFIED STREAM RESTORATION AREAS) SHALL BE RETURNED TO EXISTING CONDITIONS AND ANY OTHER DAMAGE TO EXISTING STRUCTURES SHALL BE REPAIRED BY

THE CONTRACTOR.

5. PROPOSED STRUCTURES SHALL BE CHINKED FROM THE UPSTREAM SIDE, SUCH THAT THERE ARE NO SPACES

LARGER THAN 3" X 3".

6. STREAM PROFILE VIEW ON SHEET 07. PROPOSED PIPE PROFILES ON SHEET 08.

EXISTING SANITARY CROSSING,

PROPOSED DESIGN ADDS

APPROXIMATELY 4' OF COVER

END RESTORATION AT EXISTING

48" CULVERT, 1233.55'

LOG VANE

~220 LF EXISTING 24" PIPE

AND ENDWALLS TO BE

REMOVED AND DISPOSED

OF OFF-SITE.

STONE CONSTRUCTION

ENTRANCE TO REMAIN IN

PLACE AS MAINTENANCE

ACCESS.

OUTFALL 2

OUTFALL 3

VAN WINKLE ROAD

SEE SHEET 08 FOR

ADDITIONAL OUTFALL #2

PIPE INFORMATION.

SEE SHEET 08 FOR

ADDITIONAL OUTFALL #1

PIPE INFORMATION.

SEE SHEET 08 FOR

ADDITIONAL OUTFALL #3

PIPE INFORMATION.

MATCHLINE SEE SHEET 8

T.B.R.

T.B.R.

T.B.R. T.B.R. T.B.R.

NOTE - T.B.R. INDICATES FEATURE "TO BE REMOVED"

EXISTING STORMWATER

EASEMENTS 15 FT

OFFSET FROM

PROPERTY LINES

APPROXIMATE

LOCATION OF

EXISTING SANITARY

LINE AND MANHOLE

EXISTING STREAM INVERT

PROJECTED TO PROPOSED

CENTERLINE

PROPOSED STREAM INVERT ALONG

PROPOSED CENTERLINE

STRUCTURE ROCK

(P) POOL

(R) RIFFLE

(W) WEIR

PROFILE LEGEND

EARTH FILL/SALVAGED BED

CLASS I BED MIX

IN-STREAM HABITAT LOG

SILL

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Si ll la be lin g fo r b ou ld er p oo ls N

S

±16.5' CLEARANCELATERAL SEWER LINE

L2

C2

L3

S4 6°

'53

.1 3"

W

2.

TRAV 3

ELEV = 1258.49

N 3606928.9665 E 11058160.8695

PC

2+

.0

PT = 12+85.78

R2

K

OH UTILITY LINE

±18' CLEARANCE

OH UTILITY LINE

±13.9' CLEARANCE

OH UTILITY LINE

±16.5' CLEARANCE

OH UTILITY LINE

±13.1' CLEARANCE

OH UTILITY LINE

±15.5' CLEARANCE

OH UTILITY LINE

±15.8' CLEARANCE

L2

C2

L3

C3

L4

C4

L5

C5

L6 C6

L7

C7 L8

C8

L9

C9 L10

S4 6°

'53

.1 3"

W

2.

S07°06'32.22"E

86.94'

N64°41'54.88"W 35.08'

N59°38'33.29"E 22.43'

TRAV 2

ELEV = 1251.38

N 3607011.1729 E 11057899.7493

TRAV 1

ELEV = 1239.65

N 3607075.5818 E 11057580.6169

S38°03'02.61"E 105.24'

S73°16'18.48"W

147.78'

S88°08'10.77"E

133.97'

PC

2+

.0

PT = 12+85.78

R2

PC = 13+26.71 PT

3+

.1

R3

PC

4+

.0

PT = 14+58.29

R4

PC

= 15+04.19 PT

5+

.0

R5

PC

5+

.5

PT = 16+26.77

R6

PC = 16+64.75 PT

6+

.1

R7

PC

7+

.5

PT = 17+45.46

R8

PC = 17+76.23

PT = 17+93.29

R9

S66°43'04.33"E 119.88'

PARCEL BOUNDARIES

EX. CONTOURS (1' C.I.)

EX. SANITARY

EX. STORM DRAINAGE

EX. WATER LINE

EX. EDGE OF PAVEMENT

EX. DITCH

EX. OVERHEAD TELEPHONE LINE

EX. GAS LINE

EX OVERHEAD UTILITIES

EX OVERHEAD ELECTRIC

EX , UG TELEPHONE

BNDRY 2015 TOPO. (SUPPLEMENTED

WITH ADDITIONAL SHOTS)

EX. GUARD RAIL

NEW (2022) WSSI SURVEYED TOPO.

EX. STORMWATER EASEMENTS

EX. RIPRAP

EX. TREELINE

EX. CHAINLINK FENCE

WATER METER, WATER MANHOLE,

HYDRANT, GAS VALVE, MAIL BOX

BUSH, DECIDUOUS TREE, TREE TO BE

REMOVED (SCALED BY SIZE)

FOUND IRON ROD PROPERTY MARKER

EXISTING CONDITIONS LEGEND

GEOMETRY TABLE

NO. LENGTH RADIUS BEARING/DELTA TANGENT CHORD BEARING CHORD

L2 12.50' -- N 74°31'17" W -- -- -- C2 37.72' 75.00' 28°49'04" 19.27' N 88°55'49" W 37.33' L3 40.93' -- S 76°39'39" W -- -- -- C3 53.40' 50.00' 61°11'49" 29.57' S 72°44'26" E 50.90' L4 37.97' -- N 42°08'32" W -- -- -- C4 40.21' 50.00' 46°04'44" 21.26' N 65°10'54" W 39.14' L5 45.91' -- N 88°13'16" W -- -- -- C5 24.88' 50.00' 28°30'21" 12.70' S 73°58'05" E 24.62' L6 65.50' -- N 59°42'55" W -- -- -- C6 32.21' 55.00' 33°32'58" 16.58' N 76°29'24" W 31.75' L7 37.98' -- S 86°44'07" W -- -- -- C7 17.35' 50.00' 19°53'03" 8.76' S 83°19'21" E 17.27' L8 43.48' -- N 73°22'50" W -- -- -- C8 19.87' 45.00' 25°18'15" 10.10' N 86°01'57" W 19.71' L9 30.77' -- S 81°18'55" W -- -- -- C9 17.06' 55.00' 17°46'37" 8.60' S 89°47'46" E 17.00' L10 28.38' -- N 80°54'28" W -- -- --

RADIUS POINT LOCATION TABLE

NO. NORTHING EASTING

R2 3606851.6609 11058078.7924 R3 3606963.8463 11058010.1308 R4 3606924.8995 11057910.5089 R5 3607026.2764 11057867.7296 R6 3606968.6359 11057758.2193 R7 3607071.3027 11057714.3219 R8 3606992.7083 11057645.4830 R9 3607086.9160 11057599.9685

PROPOSED PIPE OUTFALL LOCATION TABLE

NO. NORTHING EASTING

P1 3606920.62 11058110.89 P2 3606966.46 11057981.08 P3 3607015.04 11057839.71

ELEVATION

1253.65 1250.30 1244.07

M A R

, 2

1"

0'

JAB JAB NAS

09 20

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SUPPLEMENTAL TOPO

COLLECTED BY WSSI,

JULY 2022

SUPPLEMENTAL TOPO

COLLECTED BY WSSI,

JULY 2022

PROPOSED BANKFULL

CHANNEL ALIGNMENT

OUTFALL 1 (P1)

OUTFALL 2 (P2)

OUTFALL 3 (P3)

ALIGNMENT AND

STATIONING FOR

REFERENCE ONLY

BOULDER POOL STAKEOUT TABLE

REACH ID

MAIN

W

*POINT

LA

RA

S

E.

11058082.1117'

STATION

START

12+65.00'

15+00.00'

15+60.00'

16+05.00'

16+70.00'

17+75.00'

SEEOUTFALL 2

N. ELEV.

1253.37'

ANGLE

ARM

N/A

N/A

3606926.5874' 11058077.7214'3606920.6525'

3606932.6090' 3606925.7533'

11058075.8934' 11058067.1600'

1254.48' 1254.45' 1253.07'

11057870.3700'3606976.1703' 11057863.3675'3606970.4465' 11057866.5582'3606982.2915' 11057855.4972'3606977.7958'

1246.55' 1247.58' 1247.64' 1246.05'

N/A

N/A 11057815.8062'3606998.6975' 11057807.8475'3606996.3972' 11057813.8990'3607006.7595' 11057802.8533'3607006.2619'

1243.67' 1245.25' 1245.25' 1243.37'

N/A

N/A 11057776.5039'3607020.5076' 11057771.2063'3607015.8836' 11057772.3961'3607027.9657' 11057761.8560'3607023.5156'

1242.36' 1243.35' 1243.23' 1241.46'

N/A

N/A 11057711.9244'3607021.3602' 11057705.3507'3607016.0259' 11057709.3536'3607027.5841' 11057697.2470'3607024.2194'

1239.52' 1240.54' 1240.62' 1239.02'

N/A

N/A 11057609.4896'3607032.7324' 11057603.9067'3607026.0433' 11057604.5348'3607038.1292' 11057594.5444'3607032.1841'

1235.93' 1236.86' 1236.93' 1235.23'

N/A

N/A

11057973.0760'3606966.3405' 11057969.5675'3606962.2861' 11057969.4446'3606970.2852' 11057963.0180'3606966.1860'

1250.22' 1250.98' 1250.98' 1250.12'

N/A

N/A

STRUCTURE

DROP OVER

0.30'

0.30'

0.90'

0.50'

0.70'

0.00'

0.50'

*W = WEIR, LA = LEFT ARM, RA = RIGHT ARM, S = SILL (ROCK OR LOG)

CHANNEL

W

LA

RA

S W

LA

RA

S W

LA

RA

S W

LA

RA

S W

LA

RA

S

W

LA

RA

S

PLAN

(OUTFALL 1)

LA

LA

LA

LA

LA

LA

RA

RA

RA

RA

RA

RA

W

LA

RA

S W

S

W S

W S

W S

W S

W S

M A

R , 2

A s N ot ed

JTS JTS NAS

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CONSTRUCTION DETAILS.dwg

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RIFFLE NOTES:

REFER TO THE GRADING PLAN AND LONGITUDINAL PROFILE SHEETS FOR PLACEMENT OF ROCK STRUCTURES WITHIN THE RIFFLE SECTIONS SPECIFIED ABOVE.

THE "SUMMARY OF STREAM RESTORATION FEATURES ALONG BASELINE" IS PROVIDED ON THE GRADING AND LONGITUDINAL PROFILE SHEETS. THIS SUMMARY SPECIFIES THE TYPE OF

CROSS-SECTIONS AND STRUCTURES THAT SHALL BE CONSTRUCTED ALONG THE PROFILE.

J IS THE SLOPE OF THE SALVAGED SUBSTRATE. VARIABLES "H" & "J" ARE SLOPES EXPRESSED AS HORIZONTAL:VERTICAL (H:V).

TYPICAL VALUES GIVEN IN TABLE ABOVE. VARIABLES MAY BE ADJUSTED TO MINIMIZE DISTURBANCE TO TREES, BUT THE SPECIFIED SUM OF K AND L MUST BE MET OR EXCEEDED. IF BENCH WIDTHS ARE NOT SPECIFIED OVERBANK AREAS SHOULD BE GRADED WITH A 2% CROSS SLOPE EXTENDING AS FAR AS POSSIBLE WHILE STILL ALLOWING

3:1 (MAX.) TIE OUT SLOPES.

RIFFLE

ORIENTATION LOOKING DOWNSTREAM

BLRIFFLE

NOT TO SCALE

STREAM

INVERT

BANKFULL

A - (BANKFULL WIDTH)

F - (MAX BANKFULL

DEPTH) H - S

LOPE

J - SLOPE J - SLOPE

B - (1/2 BANKFULL WIDTH)

C D

G

K - (RIGHT BANKFULL

BENCH WIDTH)

H - SLOPE E -

(LOW FLOW DEPTH)

SEE REINFORCED

BED MIXTURE

SPECIFICATIONS

BL

2 G

IMPORTANT

CONTRACTOR TO ENSURE

THAT TOPSOIL AND FABRIC

ARE INSTALLED TO ACHIEVE

FINAL GRADE AND CHANNEL

DIMENSIONS. COIR FABRIC

AND TOPSOIL SHALL NOT

BULGE OUT INTO PROPOSED

CHANNEL CONVEYANCE AREA.

IN-SITU MATERIAL

REINFORCED BED MATERIAL

TO EXTEND HALF-WAY UP

SLOPE "H" TO HEIGHT 12 G

SALVAGED COBBLE/GRAVEL/SAND

SUBSTRATE FROM EXISTING STREAM

(4" DEEP IN THALWEG, TAPERED TO

LOW FLOW CHANNEL EDGE)

EARTH FILL

(AS NECESSARY)

COIR FABRIC (ECO MESH CM700 OR EQUIVALENT)

IS PLACED FROM TOP OF REINFORCED BED

MATERIAL TO 12 INCHES BEYOND BANKFULL OR

THROUGH FULL WIDTH OF BENCH TO THE TIE OUT

WITH EXISTING GRADE , WHICHEVER IS GREATER,

AND IS KEYED IN 6 INCHES AT ENDS WITH RIPARIAN

SEED MIX UNDERNEATH. COIR FABRIC TO BE

SECURED WITH WOODEN STAKES.

(ECO-STAKES OR APPROVED EQUIVALENT).

EX. GRADE

TOPSOIL, 4" DEPTH

MINIMUM

TIE OUT TO EXISTING

GRADE AT A MAXIMUM

GRADE OF 2:1

L - (LEFT BANKFULL

BENCH WIDTH)

IN-STREAM HABITAT LOG SILL NOTES:

1. THIS FEATURE IS TO BE PLACED WITHIN A TYPICAL RIFFLE SECTION. CHANNEL SHAPE DEVIATES FROM

THE RIFFLE ONLY WITHIN THE LOW STORM FLOW WIDTH, WHERE THE LOG IS SLOPED ALONG THE BED (MAX SLOPE OF 2%) AND THE STREAM INVERT MAY BE SHIFTED FROM BASELINE. REFER TO THE TYPICAL

RIFFLE CROSS SECTION DETAIL FOR RIFFLE DIMENSIONS.

2. THE IN-STREAM HABITAT LOG SILL MAY INCLUDE AN OPTIONAL LOW FLOW POOL TO BE CONSTRUCTED IMMEDIATELY DOWNSTREAM OF THE LOG. REFER TO GRADING PLAN AND PROFILE SHEETS AND LOW

FLOW POOL DETAIL FOR POOL SPECIFICATIONS.

3. SEE "STRUCTURE NOTES" FOR ADDITIONAL INFORMATION CONCERNING ALL STRUCTURES.

4. SEE GRADING PLAN AND LONGITUDINAL PROFILE FOR STATION AND INVERT ELEVATION.

5. CONTRACTOR SHALL SKEW LOG (5-20°) FROM FLOW DIRECTION. SEE GRADING PLAN FOR STRUCTURE

ORIENTATION.

6. LOG SHALL BE INSTALLED WITH A MAXIMUM SLOPE OF 2%. DIRECTION OF SLOPE SHALL CORRESPOND

WITH PLACEMENT OF LOW FLOW POOL (OPTIONAL).

BL

BL

STREAM

INVERT

EXTEND LOG A MINIMUM OF

2' BEYOND BANKFULL WIDTH

IN-STREAM HABITAT LOG SILL

NOT TO SCALE

TIE OUT TO EXISTING

GRADE AT A MAXIMUM

GRADE OF 2:1

COIR FABRIC (ECO MESH CM700

OR EQUIVALENT) IS PLACED FROM

TOP OF LOW FLOW CHANNEL,

THROUGH FULL WIDTH OF BENCH

TO 12" BEYOND BANKFULL AND IS

KEYED IN 6" AT ENDS WITH

RIPARIAN SEED MIX UNDERNEATH

BANKFULL WIDTH

FLOW

MAX LOW STORM

FLOW WIDTH

NOT TO SCALE

SEE BED

MIXTURE SPECS.

CROSS SECTION VIEW

NOT TO SCALE

30" MINIMUM

DIAMETER

ANCHOR ROCK

MAX 2% SLOPE

FLOW

PROFILE VIEW

NOT TO SCALE

12" MIN.

DIA. LOG

LOG INSTALLED

FLUSH WITH

INVERT

PROP.

STREAMBED

12" MIN.

DIA. LOG

PROFILE VIEW - WITH

LOW FLOW POOL

EX. GRADE

EX. GRADE

EX. GRADE

30" MINIMUM

DIAMETER

ANCHOR ROCK

MAX SCOUR DEPTH

HALF OF LOG DIAMETER

FLOW

NOT TO SCALE

PROP.

STREAMBED

12" MIN.

DIA. LOG

PROFILE VIEW - WITH

SPLASH LOG

EX. GRADE

12" MIN.

DIA. LOG

STRUCTURE DETAIL LEGEND

REINFORCED BED

IN-SITU MATERIAL

FILL MATERIAL

TOPSOIL (4 INCH MIN.)

FILTER FABRIC

COIR MATTING

STAKEOUT/WEIR POINT

HEADER (TOP) ROCK

WEIR ROCK

FOOTER ROCK

SPLASH ROCK

1. ALL HEADER AND FOOTER ROCKS USED IN THE MAIN CHANNEL

SHALL HAVE AN INTERMEDIATE DIMENSION OF AT LEAST 30

INCHES.

2. SILL ROCKS (OUTSIDE OF CHANNEL) SHALL HAVE AN

INTERMEDIATE DIMENSION OF AT LEAST 12 INCHES.

3. THE BOTTOM OF ALL FOOTER ROCKS SHALL BE A MINIMUM OF 18

INCHES BELOW MAX POOL ELEVATION.

4. FOR NARROW STREAMS, THE VANE HEADER ROCKS MAY BE

CONFIGURED TO TAKE THE PLACE OF THE CENTER HEADER ROCK

AS LONG AS ALL DIMENSIONS OF THE STRUCTURE ARE

MAINTAINED.

5. MORE THAN 2 ROWS OF ROCKS MAY BE NECESSARY TO ACHIEVE

PROPER DIMENSIONS.

STRUCTURE ROCK NOTES

6. STRUCTURE ROCKS SHOULD BE PLACED SO AS TO MINIMIZE GAPS BETWEEN ROCKS. (THIS MAY REQUIRE MISSHAPEN ROCKS BE SET ASIDE FOR USE ELSEWHERE.) PRIORITY SHOULD BE GIVEN TO FORMING TIGHT JOINTS AT THE TOP OF ROCKS. ANY GAPS LARGER THAN FIST-SIZED MUST BE CHINKED

ON THE UPSTREAM (BACK SIDE) OF THE STRUCTURE PRIOR TO PLACING FILTER FABRIC AND

BACKFILLING.

1. SEE LONGITUDINAL PROFILE AND STAKEOUT SHEETS FOR ADDITIONAL INFORMATION INCLUDING ELEVATIONS AND SPECIFICS REGARDING POOL ARMORING AND BED MATERIAL THICKNESS. (ANY PORTIONS OF THE CHANNEL WITH SLOPES GREATER THAN 2.0% SHALL HAVE A MINIMUM REINFORCED BED MATERIAL THICKNESS OF 1.5x THE BED MATERIAL ROCK FRACTION D50, UNLESS OTHERWISE SPECIFIED IN

THE PROFILE.)

2. REFER TO THE TYPICAL RIFFLE CROSS-SECTION FOR PLACEMENT OF COIR FABRIC ALONG THE STREAM.

3. STRUCTURES SHALL BE UNDERLAIN WITH WOVEN OR NON-WOVEN POLYPROPYLENE GEOTEXTILE AS

NOTED IN TECHNICAL SPECIFICATIONS.

4. BACKFILL BETWEEN VANES AND BANKS WITH REINFORCED BED USED IN CHANNEL.

5. ALL STRUCTURES SHALL BE KEYED INTO THE BANK, VIA SILL OR STRUCTURE ROCK PLACEMENT, A

MINIMUM OF 3 FT BEYOND BANKFULL AND COMPLETELY ACROSS ANY PLACED FILL (SEE PLAN VIEW FOR

DETAILS).

6. THE PLAN VIEWS OF ALL STRUCTURES LOCATED IN MEANDER BENDS ARE SHOWN AS LEFT MEANDERS (THE OUTER BANK SITUATED ON THE RIGHT LOOKING DOWNSTREAM). FOR A RIGHT MEANDER STRUCTURE (THE OUTER BANK SITUATED ON THE LEFT), THE PLAN VIEW SHOWN IS A MIRROR IMAGE OF WHAT SHOULD

BE CONSTRUCTED. SEE STRUCTURE STAKEOUT SHEETS FOR STAKEOUT POINT INFORMATION.

GENERAL STRUCTURE NOTES

3 PRIMARY DIMENSIONS OF ROCK:

x = LONGEST DIMENSION y = INTERMEDIATE DIMENSION z = SHORTEST DIMENSION

ROCK

MATERIAL

ROCK

GRAVEL

COARSE SAND4

TOPSOIL

BANK RUN3

THE ROCK PORTION OF THE MIXTURE SHALL CONSIST OF RIVER COBBLE (MIN. ALLOWABLE D50 = 12 INCHES) OF COLOR WHITE, TAN, YELLOW, OR BROWN. THE VOIDS WILL BE FILLED WITH A MIXTURE OF SAND, GRAVEL, AND TOPSOIL. THIS COMPOSITION WILL RESULT IN A VERY RESISTANT, ARMORED SUBSTRATE THAT WILL BE CAPABLE OF WITHSTANDING MUCH GREATER SHEAR STRESS THAN THE COMPUTATION OF THE REQUIRED D50 WOULD SUGGEST. CLASS 1 RIPRAP SHALL BE AN ACCEPTABLE ALTERNATE, SUBJECT TO CITY APPROVAL, AS LONG AS IT MEETS THE SPECIFIED SIZE

REQUIREMENTS.

BANK RUN GRAVEL MAY INCLUDE UP TO 5% CLAY, SILT, AND/OR SAND, AND UP TO 25% COBBLE (D50 = 3" TO 8").

GRAVEL MUST HAVE NATURAL COLOR (WHITE, TAN, YELLOW, OR BROWN).

"REINFORCED BED"1 MIXTURE SPECIFICATIONS

SIZE (D )50 PORTION PERCENT (%)

0.04 - 0.08 in (1 - 2 mm)

0.5 BUCKET

0.75 BUCKET

2 BUCKETS

2 BUCKETS

ORGANIC CONTENT

LOAM OR SILT LOAM WITH 3-5%

0.08 - 2.5 in (2 - 64 mm)

13 in (330 mm)

7 - 12%

35 - 40%

35 - 40%

12 - 17%

THE REINFORCED BED SHALL BE A MINIMUM OF 18" IN DEPTH. PORTIONS OF THE STREAM WITH SLOPES GREATER THAN 2.0% SHALL HAVE A MINIMUM REINFORCED BED MATERIAL THICKNESS OF 1.5X THE ROCK FRACTION D50. SEE

LONGITUDINAL PROFILE FOR LOCATIONS AND THICKNESS.

THE SAND PORTION OF THE MIXTURE SHALL CONSIST OF A WELL MIXED SAND PREDOMINANTLY 1.0 MILLIMETERS TO

2.0 MILLIMETERS IN SIZE, SUBJECT TO ENGINEER APPROVAL (I.E. WASHED CONCRETE SAND IS NOT REQUIRED). SAND

MUST BE WHITE, TAN, YELLOW, OR BROWN IN COLOR.

THE REINFORCED BED MIXTURE SPECIFIED BELOW MUST BE APPROVED BY THE PROJECT ENGINEER PRIOR TO BEING

PLACED IN THE STREAM CHANNEL.

THE TOPSOIL PORTION OF THE MIXTURE SHALL CONSIST OF 50% SIFTED, UNWASHED COARSE SAND (WITH FINES ALLOWED), 25% COMPOSTED LEAF/BARK MULCH, 25% MINERAL SILT OR FINER MATERIAL (STONE DUST FROM ROCK

CRUSHING OPERATIONS OR ANY SILT/CLAY).

1. TOPSOIL SHALL BE PLACED ON DESIGNATED AREAS WITHIN THE LOD TO A MINIMUM DEPTH OF 4 INCHES, ON TOP OF 3"

(MINIMUM) OF LOOSENED SUBGRADE.

2. ALL SALVAGED SOIL SHALL BE FROM THE "O" OR "A" HORIZONS (SEE TYPICAL SOIL HORIZON DETAIL - THIS SHEET).

HORIZONS "B" AND "C" SHALL ONLY BE USED FOR FILL MATERIAL.

3. SALVAGED SOIL SHALL ONLY BE HARVESTED FROM AREAS DESIGNATED TO BE GRADED. NO TOPSOIL SHALL BE REMOVED FROM THE SITE AND A SOIL HARVEST CAN HAPPEN AT ANY GIVEN TIME DURING CONSTRUCTION.

4. ALL HARVESTED SOIL MUST BE PROPERLY STORED IN A DESIGNATED STOCKPILE/STAGING AREA WITH APPROPRIATE E&S CONTROLS IN ACCORDANCE WITH THE CONSTRUCTION PLANS AND THE VIRGINIA EROSION AND SEDIMENT

CONTROL HANDBOOK (VESCH).

5. THE TOPSOIL MIXTURE SHALL BE WELL MIXED AND SEEDED PER THE PLANTING PLAN IMMEDIATELY FOLLOWING

INSTALLATION AND PRIOR TO STRAW AND MATTING PLACEMENT.

6. IMPORTED TOPSOIL SHALL MEET THE REQUIREMENTS SPECIFIED IN THE CONSTRUCTION SPECIFICATIONS.

TOPSOIL SPECIFICATIONS

TYPICAL SOIL HORIZON PROFILE

O HORIZON – THE TOP LAYER OF SOIL IS

COMPOSED PRIMARILY OF ORGANIC

MATERIAL, INCLUDING LEAF LITTER,

HERBACEOUS PLANTS, INSECTS, AND

MICROORGANISMS.

A HORIZON – REFERRED TO AS TOPSOIL, WHERE

SEEDS GERMINATE AND PLANT ROOTS THRIVE.

THROUGH ELUVIATION, MINERALS AND CLAYS

HAVE BEEN REMOVED, LEAVING THIS LAYER OF

SAND AND SILT.

B HORIZON – REFERRED TO AS SUBSOIL.

THROUGH PROCESS OF ILLUVIATION, SUBSOIL

CONTAINS MINERAL DEPOSITS THAT HAVE

MIGRATED FROM ABOVE SOIL HORIZON.

C HORIZON – THIS WEATHERING ROCK LAYER

IS REFERRED TO AS REGOLITH AND CONSISTS

OF UNCONSOLIDATED ROCKS AND LITTLE

ORGANIC MATERIAL THAT INHIBIT THE

GROWTH OF PLANT ROOTS

R HORIZON – THE “R” STANDS FOR ROCK AND

IT REFERS TO THE UNCONSOLIDATED ROCK OR

SOLID BEDROCK OF THIS HORIZON.

BEDROCK - R

SUBSTRATUM - C

SUBSOIL - B

SURFACE - A

ORGANIC LAYER - O

SECOND SPLASH LOG

OPTIONAL, PLACEMENT PER

GRADING PLAN AND PROFILE.

SECOND SPLASH LOG

OPTIONAL, PLACEMENT PER

GRADING PLAN AND PROFILE.

TOPSOIL (SEE TYPICAL

RIFFLE DETAIL)

LOW FLOW POOL

NOT TO SCALE

EX. GRADE

CENTER OF LOW

FLOW POOL

EARTH FILL

BANKFULL

LOW FLOW

POOL WIDTH

BL

BL

CROSS SECTION - LOW FLOW POOL

NOT TO SCALE

POOL SHIFT

LOW FLOW

POOL DEPTH

SEE GRADING AND

PROFILE FOR LOW FLOW

POOL LENGTH AND

SPECIFIC ELEVATIONS.

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CONSTRUCTION DETAILS.dwg

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Sheet #

Design Draft Approved

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Computer File Name:

Horizontal Datum:

Boundary and Topo Source:

Vertical Datum:

L:\32000s\32200\32299.01\CADD\04-ENGR\11-Final

C on st ru ct io n D et ai ls 20

C W et la nd S tu di es a nd S ol ut io ns

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P h o n e:

-7

-6 w w w .w et la n d s.

LOG VANE

NOT TO SCALE

NOT TO SCALE

PLAN VIEW

FL

O

W

B C

XS3

D

(E

XP

O

SE

D V

AN

E

LE

N

G

TH

FOOTER LOG

XS2

A1 - (BANKFULL WIDTH)

G

- (BASELIN

E LEN

G

TH

E

BU

R

IE

D

V

AN

E

LE

N G

TH

LOW FLOW

POOL

F

D

EP

AR

TU

R E

AN

G

LE

INNER BANK

VANE

HEADER LOG

ANCHOR ROCK

(TOP FLUSH WITH

CHANNEL GRADE

AT THIS POINT)

BL

BL

BK

F

TAN

G

EN

T

RADIAL LINE

RADIAL LINE

RADIAL LINE

BKF

BAR

XS1

XS1

BANKFULL ELEVATION

L1

SECTION XS1

NOT TO SCALE

B

MM

K - (BOTTOM WIDTH OF CHANNEL)

N1N2

C

A1 - (BANKFULL WIDTH)

INNER BANK OUTER BANKBL

BL

A2 - (POOL BANKFULL WIDTH)

J - MAX

POOL

DEPTH

L2

REFER TO PROFILE AND

STAKEOUT SHEETS FOR

ADDITIONAL INFORMATION

LOG J-HOOK NOTES:

VARIABLE "A1" IS THE BANKFULL WIDTH AT SECTION XS1, AND VARIABLE "A2" IS THE BANKFULL WIDTH AT SECTION XS2.

THE BANKFULL WIDTH CHANGES CONTINUOUSLY THROUGHOUT THE STRUCTURE BASED ON GRADING OF THE BAR.

VARIABLE "E" SHALL BE A MINIMUM OF 50% OF THE EXPOSED LENGTH (VARIABLE "D").

VARIABLE "F" IS IN UNITS OF DEGREES. VARIABLE "V" IS A SLOPE EXPRESSED AS HORIZONTAL:VERTICAL (H:V) AND IN

UNITS OF FT/FT.

SEE PLANVIEW FOR VARIABLE "H" SILL LENGTH AND PLACEMENT.

VARIABLES "L1" AND "J" ARE DEPTHS RELATIVE TO BANKFULL.

VARIABLES "M", "N1", "N2", "R1", & "R2" ARE SLOPES EXPRESSED AS HORIZONTAL:VERTICAL (H:V).

FOOTER LOG

NOT TO SCALE

SECTION XS3

FLOW

BANKFULL ELEVATION

D - (EXPOSED VANE LENGTH)

V - (INCLINE SLOPE OF VANE)

PROJECTED BASELINE

INVERT OF STREAMBED

J

VANE HEADER

LOG

ANCHOR ROCK (TOP

FLUSH WITH CHANNEL

GRADE AT THIS POINT)

E - (BURIED VANE LENGTH)

U

SECTION XS2

NOT TO SCALE

BANKFULL ELEVATION

A2 - (POOL BANKFULL WIDTH)

J

Q

R2

P

S - (BOTTOM

WIDTH OF POOL)

T - MINIMUM

LOG DIAMETER

R1

OUTER BANKINNER BANK

PROPOSED

STREAMBED

U

BL

BL

EXTEND LOG 3'

(MIN) INTO BANK

USE 5/16" STAINLESS STEEL

CABLE AND TWO (2) STAINLESS

CABLE CLAMPS TO BIND LOGS

TOGETHER. THREE (3) CABLE

WRAPS PER LOG STRUCTURE.

FILTER FABRIC

12" DIAM SILL ROCKS

SET AT GRADE

EXTENDING 3' (MIN)

BEYOND BANKFULL.

SEE PLANVIEW.

XS3

XS2

EXTEND LOG 3'

(MIN) INTO BANK

OUTER BANK

VANE

HEADER

LOG

FOOTER LOG

PROPOSED

STREAMBED

FILTER

FABRIC

LOG VANE WITH ROCK SILL

NOT TO SCALE

NOT TO SCALE

PLAN VIEW

12" DIAM SILL ROCKS

SET AT GRADE

EXTENDING 3' (MIN)

BEYOND BANKFULL.

SEE PLANVIEW.

FL

O

W

B

C

XS3

XS3

D

(E

XP

O

SE

D V

AN

E

LE

N

G

TH

FOOTER LOG

XS2

XS2

A1 - (BANKFULL WIDTH)

G

(B

AS

EL

IN

E

LE

N G

TH

E

BU

R

IE

D

V

AN

E

LE

N G

TH

LOW FLOW

POOL

F

D

EP

AR

TU

R E

AN

G

LE

INNER BANK

VANE

HEADER LOG

ANCHOR ROCK

(TOP FLUSH WITH

CHANNEL GRADE

AT THIS POINT)

BL

BL

BK

F

TA

N

G

EN

T

RADIAL LINE

RADIAL LINE

RADIAL LINE

BK

F

BAR

XS1

XS1

A2 - (POOL BANKFULL WIDTH)

J - MAX

POOL

DEPTH

NOT TO SCALE

SECTION XS3

FLOW

BANKFULL ELEVATION

D - (EXPOSED VANE LENGTH)

V - (INCLINE SLOPE OF VANE)

PROJECTED BASELINE

INVERT OF STREAMBED

J

VANE HEADER

LOG

ANCHOR ROCK (TOP

FLUSH WITH CHANNEL

GRADE AT THIS POINT)

E - (BURIED VANE LENGTH)

U

SECTION XS2

NOT TO SCALE

BANKFULL ELEVATION

A2 - (POOL BANKFULL WIDTH)

J

Q

R2

P

S - (BOTTOM

WIDTH OF POOL)

T - AVG. LOG

DIAMETER (MIN.)

R1

OUTER BANK

INNER BANK

PROPOSED

STREAMBED

U

BL

BL

LOG VANE WITH ROCK SILL NOTES:

VARIABLE "A1" IS THE BANKFULL WIDTH AT SECTION XS1, AND VARIABLE "A2" IS THE BANKFULL WIDTH AT SECTION XS2.

THE BANKFULL WIDTH CHANGES CONTINUOUSLY THROUGHOUT THE STRUCTURE BASED ON GRADING OF THE BAR.

VARIABLE "E" SHALL BE A MINIMUM OF 50% OF THE EXPOSED LENGTH (VARIABLE "D").

VARIABLE "F" IS IN UNITS OF DEGREES. VARIABLE "V" IS A SLOPE EXPRESSED AS VERTICAL:HORIZONTAL (V:H) AND IN

UNITS OF FT/FT.

SEE PLAN VIEW FOR VARIABLE "H" (SILL LENGTH AND PLACEMENT).

VARIABLES "L1" AND "J" ARE DEPTHS RELATIVE TO BANKFULL.

VARIABLES "M", "N1", "N2", "R1", & "R2" ARE SLOPES EXPRESSED AS HORIZONTAL:VERTICAL (H:V).

PLAN VIEW DEPICTS A STRUCTURE IN A LEFT MEANDER (WITH

THE OUTER BANK SITUATED ON THE RIGHT LOOKING

DOWNSTREAM). FOR A RIGHT MEANDER STRUCTURE (WITH

THE OUTER BANK ON THE LEFT), THE PLAN VIEW IS A MIRROR

IMAGE OF WHAT SHOULD BE CONSTRUCTED. **THE VANE IS

ALWAYS SITUATED ON THE OUTER BANK.

REFER TO PROFILE AND

STAKEOUT SHEETS FOR

ADDITIONAL INFORMATION

EXTEND FOOTER

LOGS 3' (MIN)

INTO BANK

OUTER BANK

USE 5/16" STAINLESS STEEL

CABLE AND TWO (2) STAINLESS

CABLE CLAMPS TO BIND LOGS

TOGETHER. THREE (3) CABLE

WRAPS PER LOG STRUCTURE.

FOOTER LOG

(MIN. LENGTH = D X 1.25)

FILTER

FABRIC

6BAN…