Guidelines

• Design Guidance Memorandum
  • DGM No. 1-15: Use of Personnel Safety Grates on Pipe Inlets
  • DGM No. 1-17: Corrugated Polyethylene Pipe - Superseded by DGM 1-20
  • DGM No. 1-20: Pipe Materials - REVISED
• Sample Drainage Report

Manuals

• Design of Urban Highway Drainage
• NRCS Engineering Field Handbook 
• Performance of Flexible Ditch Linings 
• HDS Manuals
  • HDS No. 02 - Highway Hydrology
  • HDS No. 03 - Design Charts for Open-Channel Flow
  • HDS No. 04 - Introduction to Highway Hydraulics
  • HDS No. 05 - Hydraulic Design of Highway Culverts
• HEC Manuals
  • HEC No. 05 - Hydraulic Charts for the Selection of Highway Culverts
  • HEC No. 10 - Capacity Charts for the Hydraulic Design of Highway Culverts
  • HEC No. 11 - Design of Riprap Revetment - SI Units
  • HEC No. 12 - Drainage of Highway Pavements
  • HEC No. 13 - Hydraulic Design of Improved Inlets for Culverts
  • HEC No. 14 - Hydraulic Design of Energy Dissipaters for Culverts and Channels
  • HEC No. 15 - Design of Roadside Channels with Flexible Linings
  • HEC No. 22 - Urban Drainage Design Manual, 3^rd Edition
  • TR-20 User Guide
  • Win TR-55 User Manual
• Pipe Video Inspection Manual

Design Aids

Maximum Pipe Deflections at Drainage Inlets
File Name	Date Updated	Description
Arched RCP Deflections	04/19/2007	Maximum deflections for Arched RCP Pipe
Circular RCP Deflections	04/19/2007	Maximum deflections for Circular RCP Pipe
Horizontal Elliptical RCP Deflections	04/19/2007	Maximum deflections for Horizontal Elliptical RCP Pipe

Miscellaneous
File Name	Date Updated	Description
Channel Lining Selection Chart	11/10/2010	Chart to be used as an aid when selecting Soil Retention Blanket Mulch (SRBM) for swales and ditches
Map of New Castle County Watersheds	04/24/2007	Watersheds Map - New Castle County
IDF Curves	09/12/2008	IDF Rainfall curves for Delaware

Related Links

SCS Soil Classifications 

This web link redirects you to the Delaware Department of Agriculture's Map Server web page. To view the SCS Soil classifications click on "GIS Maps" on the left and then select "SCS Soils" map profile from the menu located at the upper right corner of the page.

FHWA Hydraulic Engineering Toolbox V1.0.0  

This web link redirects you to the Federal Highway Administration’s (FHWA) Hydraulics Engineering website where you can download the FHWA Hydraulic Engineering Toolbox. This toolbox provides five calculators for analyzing channels, weirs, curb and gutter, rational method and detention basins.