Storm Drainage
~f ~ ~ 3 X002
PRELIMINARY
Storm Drainage
Analysis and Report
#02026
Site Location:
Willow Glen Plat
Phase 2
Prepared For:
Yelm Development Co
16106 - 54'h Place West
Edmonds, WA 98026
Prepared By:
SKILLINGS-CONNOLLY, iNC
Consulting Engineers
5016 Lacey Boulevard S.E.
Lacey, Washington 98503
(360)491-3399
TABLE OF CONTENTS
SECTION
PAGE
1. Introduction ....................................................................... .......................1
2. Existing Conditions ........................................................... .......................1
3. Infiltration Rates /Soils Report ......................................... .......................1
4. Wells and Septic Systems ................................................ .......................2
5. Fuel Tanks ........................................................................ .......................2
6. Sub-Basin Description ...................................................... .......................2
7. Analysis of 100-Yr Flood .................................................. ....................... 2
8. Aesthetic Considerations for Facilities .............................. ....................... 2
9. Facility Sizing .................................................................... .......................2
10. Covenants, Dedications, Easements ................................ .......................3
11. Property Owner's Articles of Incorporation ...................... ...................... 3
11. Erosion Control ............................................................... ...................... 3
APPENDICES
A. Project Maps (TO BE INCLUDED IN THE FINAL REPORT)
Vicinity Map
USGS Regional Topography
100-Yr Flood Map (FEMA)
Basin Map
Water Quality Treatment Area Map
B. Calculations & Computer Analysis
Facility Sizing
Waterworks Computer Modeling
C. Supporting Documentation (TO BE INCLUDED IN THE FINAL REPORT)
Soils Data
Soils Map
Soil Log Map
D. Maintenance Schedule (TO BE INCLUDED IN THE FINAL REPORT)
SKILLINGS-CONNOLLY, 1NC. . Middle Road Plaf
Consulting Engineers Storm Drainage Analysis & Report
SECTION 1 INTRODUCTION
The Willow Glen plat is a 45 lot residential development located on the north side of Middle
Road in the City of Yelm. The land is currently pasture with a few large pine trees dispersed
throughout the site and one existing residential home. The project includes the addition of 45
residential lots for single family homes, new roadways and sidewalks, sewer and water services
and stormwater facilities to treat and dispose of the project's stormwater. The proposed
roadway features and utilities will be extended from the Willow Glen phase 1 development.
The project is located in Section 19, Township 17N, Range 2E W.M.. The Thurston County's
tax parcel numbers associated with the project are 64303500400, and 64303500300.
The projecl will add approximately 3.9 acres of impervious area. Increase in stormwater runoff
resulting from the addition of paved surfaces will be treated by bioswales, or other approved
BMP's. The stormwater runoff will be infiltrated using infiltration basins sized to infiltrate 100%
of the 100-yr, 24 hr design storm. This storm drainage and analysis report is being prepared in
accordance with the Washington State Department of Ecology's stormwater Management
Manual for the Puget Sound Basin (The Technical Manual)1992.
SECTION 2 EXISTING CONDITIONS
The existing plat site consists of approximately 8.68 acres. The site is generally flat with a
slight slope to the northeast corner of the project. The area was used as pasture land. The
frontage road, Middle Street, is a 24-foot wide asphalt roadway with a shallow roadside swale,
which is used to collect and infiltrate stormwater.
There is an existing home located on the south end of the site that will remain as a part of this
development. The existing home's wells and septic system will be abandoned and the home
will connect into the proposed sanitary sewer and water mains. The existing home will have
direct access to Middle Rd. while the remaining lots will have access via the proposed interior
roads.
No well-defined downstream drainage courses can be found. It is evident in the existing
condition that storm runoff percolates rapidly and it is highly unlikely that any runoff leaves the
site.
SECTION 3 INFILTRATION RATE /SOILS REPORT
Site soils are identified by the Soil Conservation Service Soil Survey of Thurston County,
Washington as a Spanaway gravelly sandy loam, a Type 'B' soil. This soil is characterized as
very deep, somewhat excessively drained and formed on terraces.
An investigation of the site soils was performed by Skillings-Connolly, Inc. during phase 1 and
in essence verifies the presence of the Type 'B' gravelly sandy loam soil for the site.
Soil test holes were dug in the phase 1 project areas to confirm the soil types match the SCS
soils. A soil log map will be included in the final report. Based on our previous work with
projects in this area, the sandy soil has a subsurrace percolation rate in excess of 30 in / hr. A
conservative rate of 10 in ! hr will be used for design to include a factor of safety for possible
siltation of the pond bottom over time.
SKILLINGS-CONNOLLY, INC. 1 Middle Road Plat
Consulting Engineers Storm Drainage Analysis & Report
SECTION 4 WELL AND SEPTIC SYSTEM
Each lot will be served by City of Yelm STEP collection system. The holding tank is maintained
by the city and is pumped on a regular basis.
Domestic water will be provided by the City of Yelm's water distribution system.
There are two existing wells on the project site. The wells will be abandoned in accordance with
the Thurston County Department of Health and the Washington State Department of Ecology
requirements during construction.
SECTION 5 FUEL TANKS
There are no known underground storage tanks in the immediate area.
SECTION 6 SUB-BASIN DESCRIPTION
Local topography ono the surrounoing roadways preciuoe any orr-site contrioucions or runotr.
The on-site area can be broken into three sub-basins for quantity and quality treatment. The
impervious area was considered to be from back of curb to back of curb. An estimate of 600
sq-ft was used for the contributing area for each driveway from each home. Each home will
have a drywell to handle the roof runoff. The stormwater facilities for the Middle Rd frontage
improvements will treat the stormwater runoff for quantity and quality for the north half of the
roadway for the length of the adjacent proposed development. The contributing impervious
area from the frontage road improvements was considered to be the 16 ft roadway and 0.5 ft
curb. The runoff from the sidewalk was not included and the was considered to infiltrate in the
planter strip.
SECTION 7 ANALYSIS OF THE 100-YR FLOOD
The site is not subject to flooding during a 100-yr, 24-hr storm event, nor will development of
the site contribute to flooding onto downstream property. A copy of the current FEMA Flood
Insurance Map will be included in the appendix for the final report.
SECTION 8 AESTHETIC CONSIDERATIONS FOR FACILITIES
The basins will be grassed and feature gentle side slopes and will be as shallow as possible to
blend into the surrounding environment as much as possible. The use of wet ponds as a
treatment BMP will be avoided due to proximity to residential homes.
SECTION 9 FACILITY SIZING AND DOWNSTREAM ANALYSIS
The basins will be sized and analyzed using StormShed software using the Santa Barbara Unit
Hydrograph method fora 100-yr, 24-hr Thurston County storm event. As previously described,
conservative infiltration rates were used for the design calculations.
A downstream analysis will not be necessary for this site because 100% of the 100-yr, 24-hr
event will be infiltrated.
The biofiltration swales were sized per the DOE Manual based on contributing impervious area
and a 9 minute residence time. The facilities will be checked hydraulically for compliance. The
calculations are included in Appendix B of this report.
SKILLINGS-CONNOLLY, INC. _' Middle Road Plat
Consulting Engineers Storm Drainage Analysis 8 Report
SECTION 10 COVENANTS, DEDICATIONS, EASEMENTS
TO BE INCLUDED IN THE FINAL REPORT
SECTION 11 PROPERTY OWNERS ARTICLES OF INCORPORATION
TO BE INCLUDED IN THE FINAL REPORT
SECTION 12 EROSION CONTROL
Erosion control features and a construction sequence will be included on the construction plans.
If properly administered, the erosion control features will provide sufficient protection from
sedimentation migration. The site is flat, possesses extremely porous soils and will remain
protected along the perimeters while grading activity occurs. A construction entrance will be
included as part of the erasion control features.
SKlLLINGS-CONNOLLY, INC. 3 Middle Road Plat
Consulting Engineers Storm Drainage Analysis & Report
(TO BE INCLUDED IN THE FINAL REPORT)
APPENDIX A
Project Maps
Vicinity Map
USGS Regional Topography
100 Year Flood Map (FEMA)
Basin Map
Water Quality Treatment Area Map
SKILLINGS-CONNOLLY. 1NC. Middle Road Plat
Consulting Engineers Storm Drainage Analysis 3 Report
APPENDIX B
Calculations & Comauter Modelin
Facility Sizing
Waterworks Computer Modeling
SKILLINGS-CONNOLLY, INC. Middle Road Plat
Consulting Engineers Storm Drainage Analysis d Report
62-2 north Event Summary:
BasinlD Peak Q Peak T Peak Vol Area Method Raintype Event
------- (cfs) (hrs) (ac-ft) ac /Loss
B2-2 north 0.68 8.00 0.3024 3.78 SBUH/SCS TYPEIA 2yr
B2-2 north 1.34 8.00 0.5506 3.78 SBUH/SCS TYPEIA 10 yr
B2-2 north 1.69 8.00 0.6839 3.78 SBUH/SCS TYPEIA 25 yr
B2-2 north 2.06 8.00 0.8212 3.78 SBUH/SCS TYPEIA 100 yr
B2-2 north 0.32 5.00 0.1492 3.78 SBUH/SCS TYPEIA 6-month 64% 2yr
Drainage Area: B2-2 north
Hyd Method: SBUH Hyd Loss Method: SC S CN Number
Peak Factor: 484.00 SCS Abs: 0.2 0
Storrs Duc 24.00 hrs Intv: 10. 00 min
Area CN TC
Pervious 2.5400 ac 80.00 0.25 hrs
Impervious 1.2400 ac 98.00 0.17 hrs
Total 3.7800 ac
Supporting Data:
Pervious CN Data:
None Entered 80.00 2.5400 ac
Impervious CN Data:
None Entered 98.00 1.2400 ac
Pervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Fixed None Entered 0.00 ft 0.00% 15.0000 15.00 min
Impervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Fixed None Entered 0.00 ft 0.00% 10.0000 10.00 min
B2-2south Event Summary:
BasinlD Peak Q Peak T Peak Vol Area Method Raintype Event
------- (cfs) (hrs) (ac-ft) ac /Loss
B2-2south 0.49 8.00 0.2141 2.63 SBUH/SCS TYPEIA 2yr
B2-2south 0.95 8.00 0.3878 2.63 SBUH/SCS TYPEIA 10 yr
B2-2south 1.19 8.00 0.4809 2.63 SBUH/SCS TYPEtA 25 yr
B2-2south 1.45 8.00 0.5767 2.63 SBUH/SCS TYPEIA 100 yr
82-2south 0.23 8.00 0.1065 2.63 SBUH/SCS TYPEIA 6-month 64% 2yr
Drainage Area: 62-2south
Hyd Method: SBUH Hyd Loss Method: SC S CN Number
Peak Factor: 484.00 SCS Abs: 0.2 0
Storm Dur: 24.00 hrs Intv: 10. 00 min
Area CN TC
Pervious 1.7300 ac 80.00 0.25 hrs
Impervious 0.9000 ac 98.00 0.17 hrs
Totat 2.6300 ac
Supporting Data:
Pervious CN Data:
None Entered 80.00 1.7300 ac
Impervious CN Data:
None Entered 98.00 0.9000 ac
Pervious TC Data:
Fiew type: Description: Length: Slope: Coeff: Travel Time
Fixed None Entered 0.00 ft 0.00°6 15.0000 15.00 min
Impervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Fixed None Entered 0.00 ft D.00°~° 10.0000 10.00 min
,._ _ Vr'L rc~ea~."CO ,.2025'Nillow Glen?hale _ Drainaoe~oasins or Fr~m Laoc ]5,1T0<
frontage Event Summary:
Basinl0 Peak Q Peak T Peak Vol Area Method Raintype Event
------- (cfs) (hrs) (ac-ft) ac /Loss
frontage 0.06 8.00 0.0192 0.13 SBUH/SCS TYPEIA 2 yr
frontage 0.09 8.00 0.0300 0.13 SBUH/SCS TYPEIA 10 yr
frontage 0.10 8.00 0.0354 0.13 SBUH/SCS TYPEIA 25 yr
frontage 0.12 8.00 0.0408 0.13 SBUH/SCS TYPEIA 100 yr
frontage 0.03 8.00 0.0115 0.13 SBUH/SCS TYPEIA 6-month 64°'0 2yr
Drainage Area: frontage
Hyd Method: SBUH Hyd Loss Method: SCS CN Number
Peak Factor: 484.00 SCS Abs: 0.20
Storrn Uur 24.00 hrs Inty 10.00 rain
Area CN TC
Pervious 0.0000 ac 78.00 0.29 hrs
Impervious 0.1300 ac 98.00 0.08 hrs
Total 0,1300 ac
Supporting Data:
Impervious CN Data:
frontage rd 344 ft x 16.5 ft 98.00 0.1300 ac
Pervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Sheet Prototype tc just t o have some thing 300.00 ft 10.00% 0.1700 16.91 min
Impervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Fixed None Entered 0.00 ft 0.00% 5.0000 5.00 min
North Infiltration Basin
RLPCOMPUTE [north rlp] SUMMARY
2 yr Match O: 0.0000 cfs Peak Out O: 0.6773 cfs -Peak Stg: 338.00 ft -Active Vol: 2.77 cf
10 yr Match CZ: 0.0000 cfs Peak Out O: 0.7564 cfs -Peak Stg: 338.37 ft -Active Vol: 1137.29 cf
100 yr Match Q: 0.0000 c.'s Peak Out C: 0.8917 cfs -Peak Stg: 338.96 ft -Active Vof: 321623 c'
Node ID: north rlp
Desc: rlp
Stad EI: 338.0000 ft Max EI:
Contrib Basin: Contrib Hyd:
Storage Id: north infil basin Discharge Id: north infil
Node ID: north infil basin
Desc. infl pond
Start EI: 338.0000 ft Max Ei:
Contrib Basin: Contrib Hyd:
Length ss1 ss2 Width
65.0000 ft 4AOh:1v 4.OOh:1v 45.0000 ft
Control Structure ID: north infil -Infiltration control structure
Descrip: Multiple Orifice
Start EI Max EI Increment
100.0000 ft 105.0000 ft 0.10
Infil: 10.00 in/hr Multipl ier:
82-Z north E vent Summary:
BasinlD Peak Q Peak T Peak Vol Area
------ (cfs) (hrs) (ac-ft) ac
B2-2 north 0.68 8.00 0.3024 3.78
82-2 north 1.34 8.00 0.5506 3.78
82-2 north 2.06 8.00 0.8212 3.78
Drainage Area: B2-2 north
Hyd Method: SBUH Hyd
Peak Factor: 484.00
Storm Our: 24.00 hrs
Area CN
Pervious 2.5400 ac 80.00
Impervious 1.2400 ac 98.00
Total 3.7800 ac
Supporting Data:
Pervious CN Data:
None Entered 80.00
Impervious CN Data:
Nane Entered 98.00
Pervious TC Da[a:
Fiovo type: Description:
Fixed None Entered
Impervious TC Data:
Flow type: Oescriouon~.
~!xed None Enterea
Loss Method:
SCS Abs:
Inty:
TC
0.25 hrs
0.17 hrs
2.5400 ac
1.2400 ac
Length.
0.00 ft
_ength:
0.00 't
340.0000 ft
340.0000 ft
ss3
4.OOh:1 v
1.00
ss4
4.OOh:1v
Method Raintype Event
!Loss
SBUHISCS TYPEIA 2 yr
SBUH/SCS TYPEIA 10 yr
SBUH/SCS TYPEIA 100 yr
SCS CN Number
0.20
10.00 min
Slope: Coetf: Travel Time
0.00°6 15.0000 15.00 min
Slope: Coeff: Travel Time
JAO°~ '.0.0000 'OAO ruin
. ~~-'o n_ r._CL ~ ~_ !~ is i.3ier ? ~~~'~n _~ 'c Hill aoc
North
Worksheet .or Trapezoidal Channel
Project Description
Project File untitled.fm2
Worksheet Willow Glen 2
Fiow Element Trapezoidal Channe!
Method Manning's Formula
Solve For Bottom Width
Inout Data
~Vlznninas Coeficient 0.240
Channe! Slope 1.6000 ','o
Depth 2.00 in
Left Side Slope 4.000000 H : V
Right Side Slope 4.000000 H V
Discharge 0.32 cfs
Results
Bottom Width 7.87 ft
Flow Area 1.42 ft'
Wetted Perimeter 9.24 ft
Top Width 9.20 ft
Critical Depth 0.04 ft
Critical Slope 2.540135 ft/ft
IsU
O ~ C
~
Velocity 0.22 .
~ L~ USe
qm~~
ft!s 7 ~1~,
Velocity Head ~ 0.79e-3 ft -
Specinc Energy 0.17 ft
Froude Numher 0.10
Flaw is suhcritical.
li°'., ~CK~ 11-,~~
._. ~ -. ~ _ ~-.ro Maser ._. ..
South Infiltration Basin
RLPCOMPUTE [south rip] SUMMARY
2 yr Match CZ: 0.0000 cfs Peak out O: 02579 cfs -Peak Stg: 340.43 ft -Active Vol: 522.83 cf
i 0 yr Match O: 0.0000 cfs Peak Out O: 0.4233 cfs -Peak Stg: 341.26 ft -Active Vol: 1740.48 c`
100 yr Match O: 0.0000 cfs Peak Out O: 0.5946 cfs -Peak Stg: 342.08 ft -Active VoI: 3422.51 c`
Node ID: south rip
Desc: rip
Slart EI: 340.0000 ft Max EI: 344.0000 ft
Contrib Basn: Contrib Hyd:
Storage Id: south infii basin Cischaree Id south infii
Node ID: south infii basin
Desc: infii pond
Start EI: 340.0000 ft Max EI: 342.0000 ft
Contrib Basin: Contrib Hyd:
Stage Area Volume Volume
340.00 824.00 0.00 cf 0.0000 acft
341.00 1595.00 1209.50 cf 0.0278 acft
342.00 2495.00 3254.50 cf 0.0747 acft
Control Structure ID: south in fii -Infiltrati on control structure
Descrip: Multiple Orifice
Start EI Max EI Increment
340.0000 ft 345.0000 ft 0.10
Infil: 10.00 in/hr Multiplier. 1.00
82-2south Event Summary:
BasinlD Peak Q Peak T Peak Val Area Method Raintype Event
------- (cfs) (hrs) (ac-ft) ac /Loss
82-2south 0.49 8.00 0.2141 2.63 SBUH/SCS TYPEIA 2 yr
BZ-2south 0.95 8.00 0.3878 2.63 SBUH/SCS TYPEIA 10 yr
82-2south 1.45 8.00 0.5767 2.63 SBUH/SCS TYPEIA 100 yr
Drainage Area: 62-2south
Hyd Method: SBUH Hyd Loss Method: SCS CN Number
Peak Factor: 484.00 SCS Abs: 0.20
Storm Dur. 24.00 hrs Inty: 10.00 min
Area CN TC
Pervious 1.7300 ac 80.00 025 hrs
Impervious 0.9000 ac 98.00 0.17 hrs
Total 2.5300 ac
Supporting Data:
Pervious CN Data:
None Entered 80.OC 1.?300 ac
Impervious CN Data:
None Entered 98.00 0.9000 ac
Pervious TC Data:
Flow type: Cescnotion _~nnth Slope: Coeff: Travel Time
=!xed None Entered 0.00 ft 7.00°o 15.0000 15.00 min
!mpervious TC Data:
F'owi type: Cesc:ipuon. _annth: Slope: Coetf: -raved ~ ime
~xeo None Enterec C.00 rt C.00°o 10.0000 10.00 min
i~~ ~E_~-^~ -__~.:._ia~ --- -„
_ - ., __., _ ~~~. - - _-_~. -...~ c.._ _. ,,.._
South
Worksheet far Trapezoidal Channel
Project Description
Project File untitled.tm2
Worksheet Willow Glen 2
Flow Element Trapezoidal Channel
Method Manning's Formula
Solve For Channel Depth
Inout Data
^Aannings Coeff dent 0240
Channel Slope 1 .5000 ',6
Left Side Slope 4.000000 H : V
Right Side Slope 4.000000 H : V
Bottom Width 3.00 ft
Discharge 0.23 cfs
Results
Depth 1.66 in
Flow Area 1.18 ft'
Wetted Perimeter 9.14 ft
Top Width 9.11 ft
Critical Depth 0.03 ft
Critical Slope 2.735492 ft/ft
Velocity 0.19 ft/s
Velocity Head 0.59e-3 ft
Specific Energy 0.14 ft
Froude Number 0.09
Flow is subcritical.
res icYeK~2>
-. 7B e-...q .;nu 1 me--. -- r: ,. ~ _,_.;: ~ ..., ..: .:_^' _ 1 _ :ri,q ':ne ~. ~
Frontage
Worksheet for Trapezoidal Channel
Project Description
Project File untitled.fm2
Worksheet Willow Glen 2
Flow Element Trapezoidal Channel
Method Manning's Formula
Solve For Channel Deoth
Inout Data
Manninas CoeRicient 0.240
Channel Slope 1 .5000
Left Side Slope 4.000000 H : V
Right Side Slope 4.000000 H : V
Bottom Width 8.00 ft
Discharge 0.03 cfs
Results
Depth 0.49 in
Flow Area 0.34 ft'
Wetted Perimeter 8.34 ft
Top Width 8.33 ft
Critical Depth 0.01 ft
Critical Slope 4.288150 ft/ft
Velocity 0.09 ft/s
Velocity Head 0.12e-3 ft
Specific Energy 0.04 ft
Froude Numher 0.08
Flow is subcritical.
4rs.~ LF-
use ~ 1,~ ~ ~{ .~„~
... ., .. ... ..0.(18 _~_ in
r1°~~~ence)
Frontage Infiltration Rock Gallery
RLPCOMPUTE [front rlp) SUMMARY
2 yr Match O: 0.0000 cfs Peak Out Q: 0.0577 cfs -Peak Stg: 340.00 ft - AC.ive Vol: 0.00 cf
10 yr Match O: 0.0000 cfs Peak Out O: 0.0694 cfs -Peak Stg: 340.23 ft -Active Vol: 21.05 cf
100 yr Match O: 0.0000 cfs Peak Out C: 0.0694 cfs -Peak Stg: 340.8"1 ft -Active Vol: 73.13 c`
Node ID: front rlp
Desc: rlp
Start EI: 100.0000 ft Max EI:
Contrib Basin: Contrib Hyd:
Storage Id: frontage inr"iI basin Discharge !d
Node ID: frontage infil basin
Desc: infil pond
Start EI: 340.0000 ft Max EI:
Contrib Basin: Contrib Hyd:
Length Width Void Ratio
20.0000 ft 15.0000 ft 30.00
Bottom area only with infiltration
Control Structure ID: front infil -Infiltration control structure
Descrip: Multiple Orifice
Start EI Max EI Increment
100.0000 ft 105.0000 ft 0.10
Infil: 10.00 in/hr Multipl ier.
frontage Eve nt Summary:
BasinlD Peak Q Peak T Peak Vol Area
------- (cfs) (hrs) (ac-ft) ac
frontage 0.06 8.00 0.0192 0.13
frontage 0.09 8.00 0.0300 0.13
frontage 0.12 8.00 0.0408 0.13
Drainage Area: frontage
Hyd Method: SBUH Hyd
Peak Factor: 484.00
Storm Dur. 24.00 hrs
Area CN
Pervious 0.0000 ac 78.00
Impervious 0.1300 ac 98.00
Tolal 0.1300 ac
Supporting Data:
Impervious CN Data:
frontage rd 344 ft x 16.5 ft 98.00
Pervious TC Data:
Flow type: Description:
Sheet Prototype tc just t o have something
Impervious TC Data:
Flow type: Cescription:
Fixed None citered
Loss Method
SCS Abs:
Inty:
TC
029 hrs
0.08 hrs
0.1300 ac
104.0000 ft
front infil
344.0000 ft
1.00
Method Raintype Event
/Loss
SBUH/SCS TYPEIA 2 yr
SBUH/SCS TYPEIA 10 yr
SBUH/SCS TYPEIA 100 yr
SCS CN Number
0.20
10.00 min
Length: Sope: Coeff:
300.00 ft 10.00°6 0. i 700
Leng[h: S~Ope: Coeff:
0.00 a 1~0°~ 5.0000
Travel Time
16.91 min
Travel Time
5.00 min
~c_.,, - _ _ ~._, ,
(TO BE INCLUDED IN THE FINAL REPORT)
APPENDIX C
Supporting Documentation
Soils Map
Soils Data
Soil Log Map
SK/LLINGS-CONNOLLY, ;NC. Middle Road Plat
Cansulting Engineers Storm Drainage Analysis 8 Report
(TO BE INCLUDED IN THE FINAL REPORT)
APPENDIX D
Maintenance Schedule
SK/LLINGS-CONNOLLY, /NC. Middle Road Plat
Consulting Engineers Storm Drainage Analysis 8 Report