NP ROCR 503(1) 24(2) SWM Report_100.pdf

Stormwater Management Report Project: ROCR 503(1), 24(2)

SWM Plan # 8053

Date: March 2025

Applicants:

National Park Service Rock Creek Park 3545 Williamsburg Lane NW Washington, D.C.

20008

Federal Highway Administration Eastern Federal Lands Highway Division 22001 Loudoun County Parkway Building E2, Suite 200 Ashburn, VA 20147

ROCR 503(1), 24(2) Page 2

Table of Contents

1.0 Purpose

2.0 Background

3.0 Drainage Areas

4.0 Stormwater Retention Volume

5.0 BMP selection process – MEP implementation

6.0 Conclusions

Appendix A: Compliance Calculator

Appendix B: Soil Survey

Appendix C: Site Drainage Area Maps

Appendix D: Water Quality Catch Basin Constraints

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1.0 Purpose

This is the Stormwater Management Report for the 100% Plan Submittal for Project ROCR 503(1), 24(2), Resurfacing and Restoration of Piney Branch Parkway and Waterside Drive, and 17th Street Pedestrian Facilities. This project is in Rock Creek Park, in the National Capitol Region of the National Park Service, District of Columbia. The project has two distinct work areas – one each along Piney Branch Parkway and Waterside Drive.

The Waterside Drive segment is a 0.41-mile long two-lane paved roadway which provides access to Rock Creek Parkway (North and South) from Massachusetts Avenue NW. The scope of work on Waterside Drive consists of complete full-depth reconstruction of Waterside Drive from the southern intersection with Rock Creek and Potomac Parkway to Massachusetts Avenue NW and full depth reconstruction from Massachusetts Avenue NW to the northern intersection with Rock Creek and Potomac Parkway. Work will include roadway full depth reconstruction, milling and overlay, curb and gutter replacement, guardrail replacement, light post replacement, drainage improvements, and other miscellaneous work.

The Piney Branch Parkway segment is a 0.84-mile-long two-lane paved roadway located in Rock Creek Park, which provides access from Arkansas Avenue to Beach Drive, and follows Piney Branch Creek, a tributary to Rock Creek. The scope of work on Piney Branch Parkway consists of resurfacing and rehabilitation of Piney Branch Parkway from Arkansas Avenue to Beach Drive in Northwest Washington DC. Work will include roadway milling and overlay, and full depth patching in certain areas, drainage improvements, and other miscellaneous work. Work also includes construction of a new 680 foot sidewalk and boardwalk along southbound 17th Street NW and milling and paving along the same length. This work will need to tie into the recently constructed DDOT Multi-Trail Project.

National Park Service (NPS) is the property owner and will oversee maintenance of any SWM BMPs. Due the several constraints discussed below in the report, the Maximum Extent Practicable (MEP) methodology is being applied.

2.0 Background

The SWM requirements for improvement projects involving land disturbances are based on guidance outlined in “Stormwater Management Guidebook” (SWMG), January 2020 for DOEE, as governed by Chapter 5, Title 21 of the DC Municipal Regulations (DCMG). The project is located within the existing public right of way (PROW) of West Basin Drive and Piney Branch Parkway and is thus governed according to 521.2(c) which states that Best Management Practices (BMP) to the address Stormwater Retention Volume (SWRv) on site shall be provided to the MEP, as it is outlined in Appendix B of the SWMG.

3.0 Drainage Areas

A new storm sewer system with various inlets will be installed along Waterside Drive south of Massachusetts Avenue in order to direct runoff to the bioretention facility at the Rock Creek and Potomac

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Parkway interchange. This system redirects area from the southern portion of the road to the new outfall point. No changes are proposed to the existing inlets or systems on Waterside Drive north of Massachusetts Avenue.

Supplemental inlets have been added along Piney Branch Parkway to address issues with the roadway flooding. They are located upstream of and connect into the existing inlets.

New inlets are proposed on 17th Street NW to direct runoff to the bioretention basin located at the corner of Piney Branch Parkway and 17th Street NW.

4.0 Stormwater Retention Volume

The stormwater retention volume was computed according to the following per SWMG guidance outlined in Section 4.0. See Appendices for details.

SWRv = ([𝑃 × [(𝑅𝑣𝐼 × %𝐼) + (𝑅𝑣𝐶 × %𝐶) + (𝑅𝑣𝑁 × %𝑁)] × 𝑆𝐴]) / 12 where

SWRv = volume required to be retained on site (cu. ft.)

P = variable percentile rainfall event, for this project it is 1.2 inches RvI = 0.95 (runoff coefficient for impervious cover) RvC = 0.25 (runoff coefficient for compacted cover) RvN = 0.00 (runoff coefficient for natural cover) %I = percent of site in impervious cover (decimal) %C = percent of site in compacted cover (decimal) %N = percent of site in natural cover (decimal) SA = surface area (sq. ft.)

This project consists of full-depth roadway reconstruction, resurfacing and restoration of asphalt pavement, including milling and overlaying and pavement marking; resetting select concrete curbs; drainage improvements along Waterside Drive and Piney Branch Parkway.

The site area for the project encompasses those areas where construction will expose the soil. It includes the full depth pavement reconstruction and patches, but not the mill and overlay. The construction staging areas are located on existing impervious surface: at old tennis courts off Park Road for Piney Branch Parkway and below Taft Bridge for Waterside Drive.

Here is the breakdown of the areas in the proposed condition for the entire project.

Impervious and BMP Cover

(sq. ft.)

Compacted Cover

(sq. ft.)

Total Disturbed Area

(sq. ft.)

Target SWRv

(cu. ft.)

82,039 23,694 105,733 8,386

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5.0 BMP selection process – MEP implementation

The table shows the areas associated with each Site Drainage Area (SDA) and the contributing drainage area to this site area.

The project involves reconstruction of the existing roadway to address the deteriorated pavement.

The horizontal alignment will not be changed. The proposed profile grade line will be same as the existing profile grade line. Any changes made to road layout will be adjusted to match the existing roadway. Per DCMG 521.3(b)(2), the available footprint of the disturbed area in which to place BMPs is confined to the areas immediately adjacent to the road prism.

Data from the United States Department of Agriculture (USDA) National Cooperative Soil Survey (NCSS) was used to obtain soil information in the upper layers within the limits of the project area.

The Web Soil Survey was used to determine the major map units and their Hydrologic Soil Group (HSG) ratings. Soils encountered on Waterside Drive corridor were:

Joppa gravelly sandy loam, 15 to 40 percent slopes (JtD) – A soil, Sassafras gravelly sandy loam, 15 to 40 percent slopes (ScD) – B soil, Neshaminy silt loam, 15 to 40 percent slopes (NeD) – C soil, ROCR 503(1), 24(2) Page 6

Udorthents, deep 0 to 8 percent slopes (U11B) – C soil, Manor-Urban land complex, 15 to 40 percent slopes (MdD) - D soil, Urban land – Manor complex, 0 to 8 percent slopes (UsB) – D soil, and Urban land – Sassafras, 8 to 15 percent slopes (UxC) – D soil

Soils encountered on Piney Branch Parkway corridor were:

Joppa gravelly sandy loam, 15 to 40 percent slopes (JtD) – A soil, Codorus- Urban land complex (Cn) – D soil, and Udorthents (U1) – D soil

This Level 1 project within Public Right of Way (PROW) is inside the right of way.

BMP Feasibility Considerations

The Piney Branch Parkway, 17th Street, and Waterside Drive corridors are lined with trees.

Therefore, it was considered whether BMP T-2, Tree Preservation, could be used to address the SWRv requirements of the project. However, since the trees are not otherwise within the site area, it was determined that the SWRv credit provided was less than the additional requirement imposed by the increase in site area around each tree. So, while the tree line nature of the corridors will be maintained, this does not contribute any formal SWRv credit.

Two other BMP types that were considered in detail are the surface facility B-1, Traditional Bioretention, and the underground facility F-3, Three Chamber Underground Sand Filter. Two locations were identified for installation of a B-1 facility. Both facilities are Standard Bioretention, so provide 60% of their storage volume as retention volume.

A new storm drain system conveys the portion of Waterside Drive south of Massachusetts Avenue NW to a facility at the southern end of the project. Due to restrictions on the open space from archaeology, grading limits between road/ramp, impacts to trees, and vertical restrictions to tie underdrain into storm inlets, only partial treatment of the target SWRv is attained.

New inlets on 17th Street NW convey runoff to a facility at the corner of 17th Street NW and Piney Branch Parkway. Due to restrictions on the depth form the existing storm drain system at the outfall and grading limits to fit within the open space without impacting sight lines, only partial treatment of the target SWRv is attained.

Other applications of a B-1 facility, and any application of an F-3 facility, were limited by the various restrictions detailed below.

Utility Conflicts – Underground utilities including electric, water, sanitary run behind the curb line throughout the project. Any BMP option would need to be established around these utilities with minimum clearances.

Trees – Even though there are no trees within the project area, trees are present along either side of both roads. BMP options would need to be installed outside the dripline to avoid negatively impacting the root systems. The tree lined nature of the corridor therefore significantly restricts the potential locations for the surface BMPs.

Additional Construction Impacts – The scope of the project is limited to pavement rehabilitation and spot repairs. Residential and commercial entrances around the project

ROCR 503(1), 24(2) Page 7 area results substantial maintenance of traffic. Constructing additional BMP facilities or structures would expand the disturbed area to locations that would otherwise be left in their current condition, resulting in additional SWRv requirements.

Lack of Horizontal Space – There are sidewalks and trails that run alongside one side of Waterside Drive, so any surface facility would need to be located behind these pedestrian facilities.

The table below shows summarizes which of these considerations limit BMP placement in each

SDA.

SD

A

BMP Considerations

U til ity C on fli ct s

T re es

A dd iti on al C on st ru ct io n

Im pa ct s

L ac k of

H or iz on ta l S pa ce

B-1 Traditional Bioretention ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓

B-1 Traditional Bioretention ✓ ✓ ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓ ✓

B-1 Traditional Bioretention ✓ ✓ ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓ ✓

B-1 Traditional Bioretention ✓ ✓ ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓ ✓

B-1 Traditional Bioretention ✓ ✓ ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓ ✓

B-1 Traditional Bioretention ✓ ✓ ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓ ✓

B-1 Traditional Bioretention ✓ ✓ ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓ ✓

B-1 Traditional Bioretention ✓ ✓ ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓ ✓

B-1 Traditional Bioretention ✓ ✓ ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓ ✓

B-1 Traditional Bioretention ✓ ✓ ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓ ✓

B-1 Traditional Bioretention ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓

12 B-1 Traditional Bioretention ✓ ✓ ✓ ✓

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F-3 Three chamber underground sand filter ✓ ✓ ✓

B-1 Traditional Bioretention ✓ ✓ ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓ ✓

B-1 Traditional Bioretention ✓ ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓ ✓

B-1 Traditional Bioretention ✓ ✓ ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓ ✓

B-1 Traditional Bioretention ✓ ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓

B-1 Traditional Bioretention ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓

B-1 Traditional Bioretention ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓

B-1 Traditional Bioretention ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓

B-1 Traditional Bioretention ✓ ✓ F-3 Three chamber underground sand filter ✓ ✓

The project has multiple SDAs along the length of the roadway that outlet to the receiving waters through a series of short storm drain systems

The B-1 bioretention on Waterside Drive provides storage volume for 29% of the retention volume received, resulting in 37% retention provided towards the overall SWRv requirements for the various SDAs (#1-2) along Waterside Drive.

The B-1 bioretention at the corner of Piney Branch Parkway and 17th Street provides storage volume for 64% of the retention volume received, resulting in 59% retention provided towards the overall SWRv requirements for the various SDAs (#3-20) along Piney Branch Parkway and 17th Street.

The standard for those SDAs not directly treated by either bioretention basin is to either retain at least 50% of the SWRv or remove 80% of total suspended solids (TSS). However, as documented above, the installation of additional standard BMP facilities to meet either of these standards is not feasible within the project restrictions. Two additional methods were considered to provide some measure of local water quality:

DOEE directed that for locations where existing inlets are being replaced, to consider using water quality catch basins. These are three-chambered structures with internal sumps and baffles to capture debris and promote settlement of sediment. The existing inlets are being replaced and supplemented at multiple locations along Piney Branch Parkway, each of which was evaluated to see if a water quality catch basin could be added. The table of constraints for each location, including pictures, is included as Appendix D.

o The project proposes standard EFL Type 6A grate inlets, so it was considered whether water quality catch basins could be installed in the same alignment with the grate as the inlet point. However, the roadway section has a narrow one foot gutter and 11 foot lanes, so the access manholes would be partly in the gutter and partly in the travel lane. So, only curb opening water quality catch basins, which

ROCR 503(1), 24(2) Page 9 locate the structure and access behind the curb, were considered feasible.

o Portions of the corridor, especially on the south side of the road west of 17th Street, abut directly to a steep wooded hillside. Installing water quality catch basins in such conditions would require either retaining walls or extensive grading, including tree impacts. As such water quality catch basins were excluded from these locations.

o Throughout the corridor runoff from the adjacent wooded hillside drains directly into the road. As such substantially more debris, such as leaves, sticks, and displaced rocks, will reach the inlets as compared to a typical urban area. While this will increase the maintenance frequency for these structures, they will still function to provide treatment. The additional interception provided by the water quality inlets was not considered when evaluating roadway flooding, so there are no additional safety concerns even if the water quality inlets end up fully clogged between maintenance cycles. Whether a location receives runoff from a wooded area is noted, but did not disqualify the use of a water quality inlet.

o A recently installed shared use path runs along the corridor north of the road, and is frequently curb abutted or has a narrow buffer. Installing a structure that encroaches into this path is a potential obstruction and safety hazard, which would be aggravated over time as the trail and structure experience differential settling.

As such water quality catch basins were excluded from these locations.

o Various utilities run throughout the corridor, most notably a buried electric line that runs behind the curb south of the road. There is limited opportunity to relocate this line behind a potential water quality catch basin, as such activity would have additional slope grading and tree impacts. There is also limited information available, with the utility size and typical depth unknown. As such water quality catch basins were excluded from these locations.

o Based on these constraints, four locations were identified to install water quality catch basins: one in SDA #5 as structure D01-5B, two in SDA #12 as structures D04-1C and D04-1D, and one in SDA #18 as structure D05-7B.

For those SDAs served by neither a bioretention basin nor a water quality catch basin, the project proposes to install trash screens in the inlets that receive runoff from the site area.

While the benefit provided is less than the other improvements, they are not subject to the constraints noted above, and can be implemented within the scope of the project. This is the area where such practices will be most cost effective, since the various storm drain systems outfall directly to Rock Creek or Piney Branch and there is no other downstream location where the trash could be collected before polluting the natural environment.

Additionally, the following table shows the water table conflict, bedrock conflict, hot spot concerns along with the soil group of each site drainage area.

SDA # Water Table Conflict per SDA (Y/N)

Bedrock conflict per SDA (Y/N)

Hydro Soil Group per SDA

Hotspot Concern Noted (Y/N)

1 N N A, D N 2 N N A, B, C, D N 3 N N A, D N 4 N N A N 5 N N A N 6 N N A N

ROCR 503(1), 24(2) Page 10

7 N N A N 8 N N A N 9 N N A N 10 N N A N 11 N N A N 12 N N A N 13 N N A, D N 14 N N A, D N 15 N N A, D N 16 N N A, D N 17 N N A, D N 18 N N A, D N 19 N N D N 20 N N D N

Two infiltration tests were conducted for the Piney Branch BMP which returned rates of 0.05 and

0.37 inches/hour, which require the use of underdrain for the B-1 bioretention facility. Excerpts from the Geotechnical and Pavement Engineering Report dated July 5, 2024 are show below:

ROCR 503(1), 24(2) Page 11

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Additionally, three infiltration tests were previously completed for the Waterside Drive BMP.

Excerpts from the Subsurface Exploration and Infiltration Evaluation dated October 7, 2015 are shown below. While these do show high infiltration rates, they were conducted at the top of the slope, and so are approximately 30 feet above the bottom of the facility. They therefore cannot be relied on when determining facility infiltration, and the design assumes infiltration is limited.

ROCR 503(1), 24(2) Page 14

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6.0 Conclusions

This pavement restoration and repair project is subject to the MEP process. As part of the design, several BMP types are considered, specifically B-1, F-3, T-2, water quality catch basins, and inlet trash screens. B-1 bioretention is appropriate and has been proposed for both the reconstruction of Waterside Drive south of Massachusetts Avenue and the construction of sidewalk along 17th Street NW. For Waterside Drive north of Massachusetts Avenue and Piney Branch Parkway, and for Piney Branch Parkway corridor, the maximum practicable treatment within these constraints is to install water quality catch basins at appropriate locations and trash screens at the remaining untreated discharge points.

ROCR 503(1), 24(2) Page 20

Appendix A: Compliance Calculator

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Appendix B: Soil Survey

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Appendix C: Site Drainage Area Maps

NO. DATE BY REVISIONS

ASHBURN, VIRGINIA

EASTERN FEDERAL LANDS HIGHWAY DIVISION

FEDERAL HIGHWAY ADMINISTRATION

U.S. DEPARTMENT OF TRANSPORTATION ROCK CREEK PARK

NPS PMIS No. 213558/211875 NPS Drawing No. 821/193873

PROJECT

NUMBER

SHEET

DC NP ROCR 503(1), 24(2)

:3

P

M

J u n e

D I m p e r ia l S h e e t c b m s \w s p p b u s p w

\w s p h ie p .d in h \d

\N

P R

O C

R W a te r s id e P in e y B r a n c h b d r .d g n

DRAINAGE AREA MAP

STORMWATER

PINEY BRANCH PARKWAY

Legend

Limit of Disturbance

Drainage Area N

100 200050100

Scale in feet

M A

T C

H P

L A

N S

H E

E T C

C01

CDA to BMP 5-1

SDA#9

SDA#8

SDA#6

SDA#5

SDA#4

SDA#3

SDA#7

NO. DATE BY REVISIONS

ASHBURN, VIRGINIA

EASTERN FEDERAL LANDS HIGHWAY DIVISION

FEDERAL HIGHWAY ADMINISTRATION

U.S. DEPARTMENT OF TRANSPORTATION ROCK CREEK PARK

102.4

TP

ED

E

E

EOI

EOI EOI

EOI

EOI

EOI

EOI

EOI

EOI

EOI

A

C

L A

Y

N E F

UP

UP

UP

E

E

E

E

DI

SC F

OUND

M O

N F

O U

N D

NPS PMIS No. 213558/211875 NPS Drawing No. 821/193873

PROJECT

NUMBER

SHEET

DC NP ROCR 503(1), 24(2)

:3

J u n e

D I m p e r ia l S h e b m s \w s p p b u s p w

\w s p h ie p .d in h \d

\N

P R

O C

R W a te r s id e P in e y B r a n c h b d r .d g n

5'-1.7"19'-9.2"19'-3.2"4'-1"84'-6.2"9'-5.6"24'-1"16'-8.6"4.2'7.8'244.4'

Piney Branch Bioretention

BMP 17-1

CDA to BMP 17-1

BMP 12-2

CDA to

CDA to BMP 12-1

SDA#11

SDA#10

SDA#15

SDA#14

SDA#12

SDA#13

SDA#16

DRAINAGE AREA MAP

STORMWATER

PINEY BRANCH PARKWAY100 200050100

Scale in feet

Legend

Limit of Disturbance

Drainage Area

N

M A

T C

H P

L A

N S

H E

E T C

C02

M A

T C

H P

L A

N S

H E

E T C

MATCH PLAN ON THIS SHEET

MATCH PLAN ON THIS SHEET

NO. DATE BY REVISIONS

ASHBURN, VIRGINIA

EASTERN FEDERAL LANDS HIGHWAY DIVISION

FEDERAL HIGHWAY ADMINISTRATION

U.S. DEPARTMENT OF TRANSPORTATION ROCK CREEK PARK

100 200050100

Scale in feet DRAINAGE AREA MAP

STORMWATER

PINEY BRANCH PARKWAY

Legend

Limit of Disturbance

Drainage Area

N

NPS PMIS No. 213558/211875 NPS Drawing No. 821/193873

PROJECT

NUMBER

SHEET

DC NP ROCR 503(1), 24(2)

M A

T C

H P

L A

N S

H E

E T C

C03

M A T C

H P

L A

N S

H E E T C

:3

J u n e

D I m p e r ia l S h e b m s \w s p p b u s p w

\w s p h ie p .d in h \d

\N

P R

O C

R W a te r s id e P in e y B r a n c h b d r .d g n

244.4'

CDA to BMP 18-1

SDA#17

SDA#18

SDA#19

EO

I

EO

I

W M

W M

W M W

M W M W

M W M

W M

S S

M H

S S

M H

S D

M H

S D

M H

W M

W

W

W

WWW

WWWW

M

NO. DATE BY REVISIONS

ASHBURN, VIRGINIA

EASTERN FEDERAL LANDS HIGHWAY DIVISION

FEDERAL HIGHWAY ADMINISTRATION

U.S. DEPARTMENT OF TRANSPORTATION ROCK CREEK PARK

Legend

Limit of Disturbance

Drainage Area

N

DRAINAGE AREA MAP

STORMWATER

PINEY BRANCH PARKWAY100 200050100

Scale in feet

NPS PMIS No. 213558/211875 NPS Drawing No. 821/193873

PROJECT

NUMBER

SHEET

DC NP ROCR 503(1), 24(2)

M A

T C

H P

L A

N S

H E

E T C

C04 :3

J u n e

D I m p e r ia l S h e b m s \w s p p b u s p w

\w s p h ie p .d in h \d

\N

P R

O C

R W a te r s id e P in e y B r a n c h b d r .d g n

SDA#19

SDA#20

23.5 24.5

23.99

W

W

W

W W

W W

S

S

S

R

E

R

R

E

E

E

E

E

R

R R

R

R

R

R

R

R

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

W

R

R

R

E

E

R

R R R

R

E

E

E

E

E

E

E

E

E

E

R

E

J

P

P J

R

E

Ga bio n w all s

12"

W

W

W

W

W

W

W

W

W

W

W

W

W

EH

H

EV

' x

10 2010

N

SDA#1

WATERSIDE DR

AVE

MASSACHUSETTS

AVE

MASSACHUSETTS

ROCK CREEK PKWY

Bioretention

Waterside

BMP 1-1

CDA to BMP 1-1

NO. DATE BY REVISIONS

ASHBURN, VIRGINIA

EASTERN FEDERAL LANDS HIGHWAY DIVISION

FEDERAL HIGHWAY ADMINISTRATION

U.S. DEPARTMENT OF TRANSPORTATION ROCK CREEK PARK

DRAINAGE AREA MAP

STORMWATER

WATERSIDE DRIVE200 400050100

Scale in feet

Legend

Limit of Disturbance

Drainage Area

NPS PMIS No. 213558/211875 NPS Drawing No. 821/193873

PROJECT

NUMBER

SHEET

DC NP ROCR 503(1), 24(2) C05

:3

J u n e

D I m p e r ia l S h e b m s \w s p p b u s p w

\w s p h ie p .d in h \d

\N

P R

O C

R W a te r s id e P in e y B r a n c h b d r .d g n

E

E

E

O I

E O I

0 5

0 10

0 4

SDA#2

N

W A

T E

R S I D

E D

R

AVE

MASSACHUSETTS

R O

C K C

R E E

K P

K W

Y

NO. DATE BY REVISIONS

ASHBURN, VIRGINIA

EASTERN FEDERAL LANDS HIGHWAY DIVISION

FEDERAL HIGHWAY ADMINISTRATION

U.S. DEPARTMENT OF TRANSPORTATION ROCK CREEK PARK

DRAINAGE AREA MAP

STORMWATER

WATERSIDE DRIVE100 200050100

Scale in feet

W A

T E

R S I D

E D

R

R O

C K

C R

E E

K P

A R

K W

A Y

B E

L M

O N

T R

D

Legend

Limit of Disturbance

Drainage Area

NPS PMIS No. 213558/211875 NPS Drawing No. 821/193873

PROJECT

NUMBER

SHEET

DC NP ROCR 503(1), 24(2) C06

:3

J u n e

D I m p e r ia l S h e b m s \w s p p b u s p w

\w s p h ie p .d in h \d

\N

P R

O C

R W a te r s id e P in e y B r a n c h b d r .d g n

ROCR 503(1), 24(2) Page 48

Appendix D: Water Quality Catch Basin Constraints

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