1. Storm Sewer Assessment for South Newport Subdivision
Waterworks, LLC.
Storm Sewer Assessment for
South Newport Subdivision
Crosby, Texas
May 5, 2015

2. Project Limits Goal: Design a Storm Water management system.
Cover the development south of Jolly Boat Drive and encompassed by Golf Club Drive and Broken Back Drive.
Goal: Design a Storm Water management system.
Lower risk of flooding.
Use SCS method to estimate runoff volume.
EPA SWMM to direct runoff to proposed area.
DENISE
Location of Outfall

3. Project Limits Subdivison in Crosby, Texas South of Jolly Boat Drive.
Approximately 55 acre for single family homes
Area slopes from the north west to the south east.
JILLIAN
Location of Outfall

4. Preliminary Design Procedures
Existing elevations were determined from the LiDAR topographic map in AutoCAD
Subcatchment areas were found using closed polylines and the “Area” command in AutoCAD once the allowable area for a 10-foot and 15-foot inlet were calculated using the Rational Method
Pipe lengths were found by using the “Distance” command in AutoCAD
Project conformed to the standards in City of Houston Infrastructure Design Manual
A few velocities did not meet the 3 fps specification
Backfill requirements were met, with a range of 3-5 feet

5. Proposed Design 22 Subcatchment Areas 25 inlets
22 15-foot inlets
3 10-foot inlets
12 additional junctions to accommodate transitions to RCPs
Reinforced Concrete Pipes (RCPs)
3925 LF of 1-foot dia.
2965 LF of 1.5-foot dia.
1300 LF of 2-foot dia.
Outfall located at the southeast corner of the development

6. Preliminary Cost Estimate
Description
Unit
Qty
Unit Cost
Total Cost
CLEARING AND GRUBBING: 1
Clearing and Grubbing AC 8
$3,000.00
$24,000
TRENCHING AND BACKFILL: 2
Excavation CY
3640
$3.50
$12,740 3
Backfill
1500
$35.00
$52,500
STORMWATER DRAINAGE SYSTEM: 4
12" RCP drain pipe LF
3925
$34.00
$133,450 5
18" RCP drain pipe
2965
$38.00
$112,670 6
24" RCP drain pipe
1300
$48.00
$62,400 7
10-ft Inlets EA
$1,300
$3,900
15-ft Inlets 22
$1,500
$33,000 9
Manhole-Standard Depth 12
$1,800
$21,600
LANDSCAPING AND SURFACE RESTORATION: 10
Hydromulch Seeding
$1,000
$8,000 11
Stormwater Pollution Prevention Plan
$50,000
Subtotal
$514,260.00
Contingencies (15%)
$77,139.00
Engineering (15%)
$88,709.85
TOTAL
$680,108.85