29-3A  Hydrologic Symbols and Definitions

29-5A  Design Frequency (Return Period — Years)

29-6A  Selection of Discharge Computation Method

29-7A  Methods for Calculating Time of Concentration

29-7B  Roughness Coefficients (Manning’s n) for Sheet Flow

29-7C  Values of N for Kerby’s Formula

29-8A  Runoff Coefficients for the Rational Formula

29-8B  Runoff Coefficients for the Rational Formula

29-9A  Areas for Selecting Flood-Frequency USGS Estimating Equations

29-9B  Mean Annual Precipitation (1941-1970)

29-9C  Two-Year, 24-Hour Precipitation

29-9D  Major Hydrologic Soil Groups

29-9E  Prediction Equations, Standard Errors of the Estimate (SEE) and Equivalent Years of Record (EY)

29-9F  Ranges of Area Basin Characteristics for USGS Regression Equations

29-10A  Huff Distribution of Design Rainfall (50% Probability of Design Rainfall)

29-10B  NRCS Relation Between Direct Runoff, Curve Number and Precipitation

29-10C  Runoff Curve Numbers — Urban Areas

29-10D  Runoff Curve Numbers — Undeveloped Areas

29-10E  Runoff Curve Numbers — Agricultural Lands

29-10F  Conversion From Average Antecedent Moisture Conditions

29-10G  Rainfall Groups for Antecedent Soil Moisture Conditions During Growing and Dormant Seasons

29-10H  Factors for Adjusting Lag
(When Impervious Areas Occur in Watershed)

29-10 I  Factors for Adjusting Lag (When Main Channel Has Been Hydraulically Improved)

29-10 J  TR-20 Example Problem