Preliminary Design of Galvez Estates Subdivision

Summary of Topics Introduction General Site Information Sanitary Sewer Design Design of Subdivision Hydrologic Analysis Traffic Impact References

General Site Location LA 42

General Site Information Development Site: Tracts A & B Development Size: 47.9 Acres Lot Size: 70’x150’ Minimum Number of Lots: 100 Land Cost: $30,000/acre Construction Cost: $450/linear foot of street Profit Goal: >$2.5 million

Sanitary-Sewer Design Pipe Size Design Based on:  Peak Flowrate  Manning’s with PVC Pipes Flowing Half-Full Q peak = 1.69 cfs Diameter = 1.7” ~ 2” Per EBR: Minimum Pipe size = 8”

Sanitary-Sewer Design Velocity Requirements  Minimum Velocity = 2 fps  Maximum Velocity = 10 fps Manning’s with PVC Pipes Flowing Half-Full V = 2.4 fps

Sanitary-Sewer Design

Design of Subdivision

Lot size of 70’x 150’ Lot frontage along Curved Right of Ways held to 70’ at building line Building Lines held to 25’ 122 lots Curb and gutter with subsurface drainage

Design of Subdivision Road Design  12 feet utility servitude outside 50 ft right-of-way  Surfaced with 3”asphalt cement over 12” soil cement sub base  Road designed above Base Flood Elevation of 18’  Minimum road slope of 0.4%

Road Cross Section

Preliminary Earthwork CUTFILL POND96,500 C.Y ROADWAYS8,700 C.Y.1,900 C.Y. LOTPADS T.B.D.

Drainage Design Site Conditions  Topography  Soil Types  Flood Zone Pre-Development Drainage Post-Development Drainage Fill Mitigation Design Storm

Soil Types Calhoun Silt Loam  81.1% of Site Deerford-Verdun Complex  17.9% of Site Olivier Silt Loam  1% of Site Predominately Hydrologic Group D

FEMA F.I.R.M. FIRM Panel# 2205C0035E Flood Zones “AE” & “X” BFE=18.0’

Pre-Development

Catchment Area 1Discharge Rational Method  Weighted Runoff Coefficient, C = 0.32  Intensity, I = 4.0 in/hr (EBR Drainage Manual)  Area, A = 47.2 Ac (Includes 7 Ac of adjacent land) Pre Development Discharge, Q = 60.4

Post Development

Fill Mitigation Not an Issue Majority of Site is above Base Flood Elevation  1,100 C.Y. of Storage Loss due to Fill Pond Normal Pool Below B.F.E.  B.F.E.=18.0’  Normal Pool = 13.75’  Potential for >30,000 C.Y. of Storage Offsets Loss due to Fill

Design Storm 10 yr, 24 hr Event Total Rainfall = 8.5” (EBR Drainage Manual) Modeled in HydroCAD  SCS - Type III Event

Post-Development Hydrograph

Current Site Conditions Route: LA0042 milepoint: station: Year – ADT 2007 – Route: LA0933 milepoint: 0.82 station: Year – ADT

Traffic Impact Analysis (Per Institute of Transportation Engineers’ Trip Generation Model)

Design Vehicle S-Bus36 Minimum Design Turning Radius = 38.9’ Centerline Turning Radius = 34.9’ Minimum Inside Radius = 23.8’

Galvez La 932 La 932 Galvez Boulevard

Permits Lousiana DOTD  Right Of Way Permits  Highway Access, Utilities, Vegetation Department of Health And Hospitals  Sanitary Sewer, Onsite Treatment Ascension Parish  Subdivision Permit

References East Baton Rouge Parish Unified Development Code Trip Generation – Institute of Transportation Engineers - 6 th Edition Google Maps AASHTO Guide for Design of Pavement Structures