Preliminary Design of Galvez Estates Subdivision

Preliminary Design of Galvez Estates Subdivision

Summary of TopicsIntroductionGeneral Site InformationSanitary Sewer DesignDesign of SubdivisionHydrologic AnalysisTraffic ImpactReferences

General Site Location

LA 42

General Site InformationDevelopment Site: Tracts A & BDevelopment Size: 47.9 AcresLot Size: 70x150Minimum Number of Lots: 100Land Cost: $30,000/acreConstruction Cost: $450/linear foot of streetProfit Goal: >$2.5 million

Sanitary-Sewer DesignPipe Size Design Based on:Peak Flowrate

Mannings with PVC Pipes Flowing Half-Full

Qpeak = 1.69 cfs

Diameter = 1.7 ~ 2Per EBR: Minimum Pipe size = 8

Sanitary-Sewer DesignVelocity Requirements

Minimum Velocity = 2 fpsMaximum Velocity = 10 fps

Mannings with PVC Pipes Flowing Half-Full

V = 2.4 fps

Sanitary-Sewer Design

Design of Subdivision

Design of SubdivisionLot size of 70x 150Lot frontage along Curved Right of Ways held to 70 at building lineBuilding Lines held to 25122 lotsCurb and gutter with subsurface drainage

Design of SubdivisionRoad Design

12 feet utility servitude outside 50 ft right-of-way

Surfaced with 3asphalt 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 EarthworkCUTFILLPOND96,500 C.Y.-------ROADWAYS8,700 C.Y.1,900 C.Y.LOTPADS--------T.B.D.

Drainage DesignSite ConditionsTopographySoil TypesFlood ZonePre-Development DrainagePost-Development DrainageFill MitigationDesign Storm

Soil TypesCalhoun Silt Loam 81.1% of SiteDeerford-Verdun Complex 17.9% of SiteOlivier Silt Loam 1% of Site

Predominately Hydrologic Group D

FEMA F.I.R.M.

FIRM Panel#2205C0035EFlood Zones AE & XBFE=18.0

Pre-Development

Catchment Area 1DischargeRational MethodWeighted Runoff Coefficient, C = 0.32Intensity, I = 4.0 in/hr (EBR Drainage Manual)Area, A = 47.2 Ac (Includes 7 Ac of adjacent land)

Pre Development Discharge, Q = 60.4Post Development

Fill MitigationNot an Issue

Majority of Site is above Base Flood Elevation1,100 C.Y. of Storage Loss due to Fill

Pond Normal Pool Below B.F.E.B.F.E.=18.0Normal Pool = 13.75Potential for >30,000 C.Y. of Storage Offsets Loss due to FillDesign Storm10 yr, 24 hr EventTotal Rainfall = 8.5 (EBR Drainage Manual)Modeled in HydroCADSCS - Type III Event

Post-Development HydrographCurrent Site ConditionsRoute: LA0042milepoint: 19.61station: 205510Year ADT2007 12566

Route: LA0933milepoint: 0.82station: 205530Year ADT2007 - 5684

Traffic Impact Analysis

(Per Institute of Transportation Engineers Trip Generation Model)Design Vehicle S-Bus36Minimum Design Turning Radius = 38.9Centerline Turning Radius = 34.9Minimum Inside Radius = 23.8

Galvez Boulevard @ La 932

La 932Galvez BoulevardPermitsLousiana DOTD Right Of Way PermitsHighway Access, Utilities, Vegetation

Department of Health And HospitalsSanitary Sewer, Onsite Treatment

Ascension ParishSubdivision Permit

ReferencesEast Baton Rouge Parish Unified Development CodeTrip Generation Institute of Transportation Engineers - 6th EditionGoogle Mapswww.DOTD.Lousiana.govAASHTO Guide for Design of Pavement Structures

Sheet1Column1Column2Column3Column4Column5Column6Column7Column8Single Family Detached Housing - 122 Dwelling UnitsAvg. Trip Ends on a:Trip EndsInOutWeekday, between 7 and 9 a.m.T = 0.700(X) + 9.477952471Weekday, between 4 and 6 p.m.Ln(T) = 0.901 Ln(X) + 0.5271298247Saturday, peak hourT = 0.886(X) + 11.0651176354Sunday, peak hourT = 0.756(X) + 23.8151166254

Sheet2

Sheet3