City of Lincoln
Watershed Stormwater Master Plans

Stevens Creek

Table of Contents
Volume I - Study Report

Cover Page (238 K)

Executive Summary (1.29 M)

Section 1 - Introduction and Purpose (564 K)

• 1.1 Introduction
  • 1.1.1 Project Team
  • 1.1.2 Watershed Location
• 1.2 Goals and Objectives
• 1.3 Public Participation Process
  • 1.3.1 Questionnaire Survey
  • 1.3.2 Open House Events
  • 1.3.3 Citizen Advisory Committee
  • 1.3.4 Property Owner Meetings and Stakeholder Sessions
  • 1.3.5 Website and Newsletter
  • 1.3.6 Watershed Bus Tours

Section 2 - Data Collection and Development (515 K)

• 2.1 Watershed Inventory
• 2.2 Drainage Structure Field Survey
• 2.3 Base Mapping/Triangular Irregular Network
• 2.4 Longitudinal Profile Survey
• 2.5 Geomorphic Investigation
  • 2.5.1 Geomorphic Background Investigation
  • 2.5.2 Geomorphic Field Investigation

Section 3 - Hydrologic Model Development (1.44 M)

• 3.1 Introduction
• 3.2 Hydrology Methodology
  • 3.2.1 Subarea Delineation
  • 3.2.2 Rainfall
  • 3.2.3 Runoff Volume (SCS CN)
  • 3.2.4 Runoff Hydrographs (Lag Time)
  • 3.2.5 Routing (Muskingum-Cunge)
  • 3.2.6 Watershed Storage
  • 3.2.7 Flow Diversions
• 3.3 Model Calibration
  • 3.3.1 Historical Storm Event Calibration
  • 3.3.2 Peak Flow Verification
• 3.4 Stream Gauge Statistical Analysis
• 3.5 Modeling Results

Section 4 - Hydraulic Model Development (226 K)

• 4.1 Introduction
• 4.2 HEC-RAS Model Development
  • 4.2.1 Stream Network, Cross Sections and Reach Lengths
  • 4.2.2 Manning's n-Values
  • 4.2.3 Roadway Crossings and Dams
  • 4.2.4 Expansion and Contraction Coefficients
  • 4.2.5 Boundary Conditions
  • 4.2.6 Ineffective Flow Areas
  • 4.2.7 Channel Bank Stations
• 4.3 Special Modeling Cases
  • 4.3.1 Stevens Creek Overflow Channel
  • 4.3.2 Split Flow Occurrences
• 4.4 Floodway Determination
• 4.5 Model Verification

Section 5 - Floodplain Management Tools (2.45 M)

• 5.1 Flood Prone Areas
  • 5.1.1 Flood Insurance Certificates
  • 5.1.2 Floodplain Delineation Process
  • 5.1.3 Study Floodplain and Floodway Maps
• 5.2 Floodplain Management Strategy

Section 6 - Water Quality and Stream Stability (928 K)

• 6.1 Background
• 6.2 Regulatory Compliance
• 6.3 Evaluation Approach
• 6.4 Biological Assessment
  • 6.4.1 Methodology
  • 6.4.2 Summary and Recommendations
• 6.5 Stream Sustainability Analysis
  • 6.5.1 Methodology
  • 6.5.2 Watershed Management Scenarios
  • 6.5.3 Modeling Results
• 6.6 Evaluation Results
  • 6.6.1 Major Conclusions
  • 6.6.2 Recommendations
• 6.7 Implementation Methods
  • 6.7.1 Method 1 - Regional Stormwater Facilities
  • 6.7.2 Method 2 - Revised Standards for Site-Specific Stormwater Facilities
  • 6.7.3 Comparison Evaluation
  • 6.7.4 Recommendations

Section 7 - Drainage Criteria Manual Review (551 K)

• 7.1 Background
• 7.2 Integrating Stormwater Detention with Structural BMPs
  • 7.2.1 Extended Dry Detention Basin
  • 7.2.2 Extended Wet Detention Basin
  • 7.2.3 Water Quality Control Volume
• 7.3 Alternative Design Approaches
• 7.4 Facility Ownership and Maintenance
  • 7.4.1 Maintenance Ordinance
  • 7.4.2 Maintenance Agreement
  • 7.4.3 Maintenance Plan

Section 8 - Geomorphic Evaluation (895 K)

• 8.1 Fundamentals of Fluvial Geomorphology
  • 8.1.1 Major Models
  • 8.1.2 Temporal and Spatial Implications
  • 8.1.3 Sediment Transport
• 8.2 Results: Evaluation of Process Indicators
  • 8.2.1 Geometrics
  • 8.2.2 Boundary Material
  • 8.2.3 Hydraulics
  • 8.2.4 Sediment Transport Competency
• 8.3 Physical Stability of the Watershed
  • 8.3.1 Existing Channel Process
  • 8.3.2 Erosion Hazard
• 8.4 Methods of Management
  • 8.4.1 Watershed-Scale Stability
  • 8.4.2 Local Stability
  • 8.4.3 Conclusions

Section 9 - Capital Improvement Projects (3.15 M)

• 9.1 Problem Identification
  • 9.1.1 Drainage Infrastructure
  • 9.1.2 Habitable Buildings
  • 9.1.3 Natural Streams
  • 9.1.4 Summary
• 9.2 Recommended Improvements
  • 9.2.1 Methodology
  • 9.2.2 Stream Interventions
• 9.3 Capital Improvement Projects
• 9.4 Other Areas of Concern

Section 10 - Implementation (340 K)

• 10.1 Setting Priorities
  • 10.1.1 Evaluation Criteria
  • 10.1.2 Other Considerations
• 10.2 Implementation Issues
  • 10.2.1 Maintenance Funding
  • 10.2.2 Policy and Ordinances
  • 10.2.3 Education Program
  • 10.2.4 Coordination Efforts
• 10.3 Areas of Interest

Section 11 - Digital Deliverables (36 K)

• 11.1 Electronic Files
• 11.2 GIS Shapefiles

Section 12 - Glossary of Terms and References (96 K)

• 12.1 Glossary of Terms
• 12.2 References