Hydraulics Report.pdf

Final

Hydraulics Report Sacramento Island Trailhead

CA FLAP RED 2017(3)

Shasta County, California

Federal Highway Administration Central Federal Lands Highway Division

12300 West Dakota Avenue Lakewood, Colorado 80228

Prepared by:

July 2021

Final Hydraulics Report Sacramento Island Trailhead i

Contents

Acronyms and Abbreviations ......................................................................................................................................... iii

1. Introduction

1.1 Existing Conditions

1.1.1 General

1.2 Floodplain

1.3 Wetlands

2. Drainage Design Criteria and Methodology

2.1 General

2.2 Hydrology

2.2.1 Major Basin Analysis

2.2.2 Minor Basin Analysis

2.3 Hydraulics

2.3.1 Culverts

2.3.2 Ditches

2.3.3 Floodplain

2.3.4 Floodway

2.4 Pavement Drainage

2.5 Erosion Control

2.6 Miscellaneous

3. Hydrologic Analysis

3.1 Minor Culverts

3.2 Ditches

3.3 Sacramento River

4. Hydraulic Analysis

4.1 Minor Culverts

4.2 Ditches

4.3 Floodway

4.4 Sub Drains

5. Recommended Improvements

5.1 Minor Culverts

5.2 Ditches

5.3 Floodway

6. Erosion and Sediment Control

6.1 Construction BMPs

6.2 Permanent BMPs

7. References ii

Appendixes

Appendix A FEMA Floodplain Mapping Appendix B Hydrologic Calculations Appendix C Hydraulic Calculations Appendix D Floodway Area Analyses Appendix E Site Photos Appendix F Field Report

Tables

3-1 Rational Method Results for Driveway Culverts 4-1 Summary of HY8 Hydraulic Analysis 4-2 Summary of FlowMaster Ditch Hydraulic Analysis 4-3 Results of Floodway Area Blockage Analysis

Figures

1 Location Map and Vicinity Map 2 Project APE Map 3 Looking Toward Proposed Parking Lot 4 Existing Footpath Along River 5 100-Year Sacramento River Flows iii

Acronyms and Abbreviations

APE Area of Potential Effects

BMP best management practice

CFLHD Central Federal Lands Highway Division cfs cubic feet per second

CMP Corrugated Metal Pipe

CVFPB Central Valley Flood Protection Board

FEMA Federal Emergency Management Agency

FIRM Flood Insurance Rate Map fps feet per second

HW/D headwater depth/diameter

I # Interstate #

PDDM Project Development and Design Manual

1. Introduction

This Hydraulics Recommendations Report describes the hydrologic and hydraulic design recommendations for the Sacramento Island Trailhead project, which consists of constructing a new recreational trail and parking area in the Riverland Open Space along the Sacramento River in Shasta County, California (Figure 1). The project area is approximately 7.9 miles south-southeast of the City of Redding. The project would be constructed in one phase and construction activities would include site preparation, clearing, grading and compacting, drainage improvements in the parking area, and construction of an asphalt parking lot and trail. The parking amenities would include a precast restroom facility, parking delineations, signage, striping, and other typical items.

The project is located 0.5 mile south of the intersection of Interstate 5 (I-5) and Knighton Road, off southbound Riverland Drive, which is the interstate frontage road. The proposed parking facility will be accessed off Riverland Drive. The parking lot will have a one-way southbound flow and exited on the south end with a second lot access.

The proposed trail begins at the south end of the proposed parking facility and heads southward. Once the trail meets the Sacramento River, the proposed alignment roughly follows the river and existing footpath westward for approximately 3,900 feet. The trail will end at the Bureau of Land Management property line.

The proposed area of potential effects is shown on Figure 2.

1.1 Existing Conditions

1.1.1 General

The site is accessed from Riverland Drive, approximately 0.5 mile south of the interchange of I-5 and Knighton Road. An existing ditch runs parallel to Riverland Drive. A reinforced concrete culvert is located under Riverland Drive near the project site and conveys flows from the east side of the road to the west.

Jersey barriers were set up at the outlet of the culvert to serve as energy dissipation and flow training to direct the flow into the roadside ditch, which conveys flow toward the Sacramento River.

There is an existing driveway from Riverland Drive to a property adjacent to the proposed parking lot, which can be used for one of the new parking lot accesses. The area for the proposed parking lot is currently undeveloped land covered with native grass. There is a gravel parking area in the vicinity of the proposed parking area. An existing dirt/gravel path runs from the existing parking area, along a chain link fence, to a non-paved path running through a wooded area (Figures 3 and 4). The path eventually parallels the Sacramento River; meandering though the wooded overbanks of the river. See site photos in Appendix E.

Figure 1. Location Map and Vicinity Map

Figure 2. Project APE Map

Figure 3. Looking Toward Proposed Parking Lot

Figure 4. Existing Footpath Along River

1.2 Floodplain

The project is located within a Zone AE and Zone AO Federal Emergency Management Agency (FEMA)-regulated floodplain according to the Flood Insurance Rate Map (FIRM) for Shasta County, California and Incorporated Areas, Panel 1564 of 2325, Map Number 06089C1564G, Community Number 060358, Panel Number 1564, Effective Date March 17, 2011. See floodplain map in Appendix B. The 100-year water surface elevation through the project area ranges from approximately 427.6 to 428 feet.

The elevation of the trail ranges from 419 to 430.

The majority of the proposed trail is located along and within the fringe of the Sacramento River floodway.

1.3 Wetlands

An Aquatic Resources Delineation Report was prepared for this project, dated July 2019. There were no wetlands or waters of the US identified within the project study area.

2. Drainage Design Criteria and Methodology

2.1 General

The drainage design for the project is in accordance with the Central Federal Lands’ Project Development and Design Manual (PDDM) Chapter 7.

A project site visit was conducted on April 10, 2019. Representatives from Central Federal Lands Highway Division (CFLHD), the City of Redding, and Jacobs walked the proposed trail alignment and the proposed parking area. Existing site conditions were documented through photographs and notes.

2.2 Hydrology

Hydrology was not evaluated for the Sacramento River or along the proposed trail. The Rational Method was used to analyze small drainage basins tributary to parking lot ditches and new driveway culverts.

2.2.1 Major Basin Analysis

The project is located within the Sacramento River basin with the proposed parking lot located in the floodplain and the proposed trail located mostly within the Sacramento River floodway. Hydrology for the Sacramento River was obtained from published sources. The FEMA Flood Insurance Study states that the 100-year flow upstream of the site is 79,000 cubic feet per second (cfs) at Keswick Dam and 112,000 cfs downstream of the site above the confluence with Churn Creek (Figure 5).

Figure 5. 100-Year Sacramento River Flows

2.2.2 Minor Basin Analysis

Minor basins consist of basins tributary to new culverts and drainage ditches adjacent to the parking lot and driveways. Basins tributary to the culverts are relatively small and runoff can be analyzed using the Rational Method based on a 10-year design flow.

A culvert will be added under the trail where an area on the upstream side of the trail will be excavated to balance earthwork. No hydrologic analysis was performed for this culvert.

2.3 Hydraulics

2.3.1 Culverts

FHWA’s HY-8 Culvert Hydraulic Analysis Program (HY-8) was used to determine the size, type, and conveyance of new culverts along the parking lot based on a 10-year design flow.

Culvert slopes are a minimum of 0.5 percent where there are cover issues and to minimize outlet velocities.

New culverts will have a minimum service life of 50 years. The gage of pipe is of a thickness to achieve the required minimum service life. Plastic pipes are not proposed because of the potential for wildfire damage.

Minimum pipe size for driveway culverts is 18 inches.

Outlet energy dissipation is based on CFLHD standard for placed riprap.

2.3.2 Ditches

Ditch hydraulics were analyzed using the Manning’s Equation within Bentley’s FlowMaster. Ditches were evaluated for depth, velocity and stability for the 10-year design event, with water surface not exceeding the bottom of the pavement aggregate base layer.

2.3.3 Floodplain

The approving jurisdiction for work within the FEMA Floodplain and Floodway is the Shasta County floodplain administrator. The floodplain administrator stated that the fill work for the parking lot, which is in the floodplain and not the floodway, would be acceptable with no submittals required through FEMA.

2.3.4 Floodway

The Shasta County floodplain administrator stated that any work within the floodway, which includes portions of the trail, would need to be designed for a net zero fill to avoid the need for a FEMA review. See Field Report in Appendix F.

A floodway encroachment permit application was filled out and submitted to the Central Valley Flood Protection Board (CVFPB), along with appropriate fees. It is anticipated that the trail will create less than 1 percent blockage within the floodway, as described and calculated in Section 5 of this memorandum.

2.4 Pavement Drainage

The parking lot will sheet flow to adjacent ditches. No curbs are anticipated within the parking area. For the trail, it is anticipated that drainage will sheet flow across the paved trail, thereby not requiring ditches or culverts.

2.5 Erosion Control

Temporary best management practices (BMP) as shown in the standard CFLHD details will be used for control of erosion during construction. Riprap will serve as permanent erosion control at culvert outlets following CFLHD standard details.

2.6 Miscellaneous

Increase in peak discharge because of project improvements will be insignificant and thus, will not be mitigated through detention or retention. No stormwater quality facilities are proposed for this project.

3. Hydrologic Analysis

3.1 Minor Culverts

The Rational Method was used to determine the 10-year flow to the driveway culverts along the parking area. A summary of the results is shown in Table 3-1. Hydrologic calculations are included in Appendix B.

Table 3-1. Rational Method Results for Driveway Culverts

C Tc (minutes) i10 (inches/hour) A (acres) Q10 (cfs)

North Culvert 0.45 5.1 4.26 3.15 6.0

South Culvert 0.45 7.8 3.61 4.82 7.8

An existing 36-inch RCP culvert crosses Riverland Drive south of the parking area culverts. This culvert will be extended by others during work on Riverland Drive.

3.2 Ditches

Hydrology for ditches along the parking area used the same values calculated for the minor culverts. The 10-year flow for the north and south ditches is the same as for the north and south culverts, respectively.

For the ditch downstream of the parking area culverts, its hydrology was conservatively derived by adding the 10-year flow from the south culvert (7.8 cfs) to the capacity of the Riverland Drive culvert allowing for one foot of freeboard at the upstream end (44 cfs) to equal 51.8 cfs.

3.3 Sacramento River

No new hydrologic analysis was performed for the Sacramento River. The FEMA Flood Insurance Study states that the 100-year flow upstream of the site is 79,000 cfs at Keswick Dam and 112,000 cfs downstream of the site above the confluence with Churn Creek.

4. Hydraulic Analysis

4.1 Minor Culverts

HY8 was used to determine the size of the driveway culverts along the parking area and the existing 36” culvert under Riverland Dr. A summary of the results is shown in Table 4-1. Output reports are in Appendix C.

Table 4-1. Summary of HY8 Hydraulic Analysis

Q10

(cfs) Slope

(feet/foot) HW D (ft) HW/D

Outlet Velocity (fps)

North Culvert (Sta. 55+71) 6.0 0.0075 1.41 2 0.71 2.8

South Culvert (Sta. 50+35) 7.8 0.0050 1.72 2 0.86 3.3

Riverland Culvert (Sta. 45+35) 44 0.0073 3.56 3 1.19 8.79 fps = feet per second HW/D = headwater depth/diameter

The hydraulic capacity of the existing 36-inch RCP culvert under Riverland Drive is approximately 44 cfs, assuming 1 foot of freeboard between the headwater elevation and the roadway overtopping elevation at the upstream end of the culvert. No hydraulic analysis was performed for the 24” equalization pipe near station 26+78.

4.2 Ditches

V-ditches along the parking area and a trapezoidal ditch downstream of the Riverland Drive culvert were analyzed using the Manning’s Equation within FlowMaster. The hydraulic results for ditches are included in Table 4-2. Output reports are included in Appendix C.

Table 4-2. Summary of FlowMaster Ditch Hydraulic Analysis

Q10 (cfs) Slope

(feet/foot) Z1* Z2* Depth Velocity (fps)

North Ditch 6.0 0.005 2 2 1.29 1.82

South Ditch 7.8 0.005 2 2 1.42 1.94

Downstream Ditch 51.8 0.0014 2 2 1.86 1.77

*The foreslope along the County Road is 1:2 and the backslope varies between 1:2 and 1:8. 1:2 was used for both foreslope and backslope in the calculations to compute maximum flow depth.

4.3 Floodway

The majority of the proposed trail is located within the Sacramento River floodway and was evaluated in accordance with the Shasta County and CVFPB guidelines.

Shasta County states that there should be no rise in water surface elevation within the floodway from the improvements so that a FEMA review for a Conditional Letter of Map Revision would not be required. It was agreed with the County that a net zero fill within the floodway would demonstrate no adverse impacts and meet the requirement for no rise in water surface elevation. The proposed trail surface was designed to be as close to the existing ground surface as possible, but areas of cut and fill were also needed. One area near station 26+00 required additional cut on the uphill side of the trail to balance the earthwork. A 24-inch culvert was placed at this location to drain the cut area. Other cut areas are minor in comparison and allow drainage to pass over the trail. The output of the earthwork balancing analysis is included in Appendix D.

CVFPB follows the U.S. Army Corps of Engineers guidance from the Categorical Permission Blockage Calculation Procedures, Categorical Permission for Section 408 Requirements Sacramento District, dated January 2019. According to this document, “The blockage is calculated as a percentage by dividing the blockage area by the total cross-sectional area of the floodway conveyance up to the design water surface elevation (DWSE) or discharge elevation at the encroachment location” and “if the blockage screening calculation indicates a floodway conveyance blockage of less than 1% at the design discharge, typically no additional analysis will be required.” A channel cross section through the narrowest width of floodway in the project area was evaluated to determine the 100-year flow area within the floodway at that section.

The section was at Section V of the floodplain model documented in the Flood Insurance Study, which has a floodway width of 893 feet. The trail cross sections were then evaluated to determine the maximum fill area that would occur along the project. The results of the estimated areas are included in Table 4-3 conservative estimate using the maximum trail fill and the minimum floodway area revealed a blockage of approximately 0.5%, which requires no additional analysis for CVFPB. See floodway area analysis in Appendix D.

A balance of cut and fill was designed along the trail so that there would be a net zero fill within the floodway.

Table 4-3. Results of Floodway Area Blockage Analysis

Cross-sectional Area

Floodway portion of sample cross section 14,390 sf

Maximum fill section along trail 77 sf

Percent blockage 0.5%

4.4 Sub Drains

No need for sub drains has been identified for this project.

5. Recommended Improvements

5.1 Minor Culverts

Although minor culverts at the parking lot accesses can be a minimum of 18 inches in diameter, 24-inch pipe culverts are recommended to improve conveyance and maintainability of the culverts with minimum slopes of 0.005 feet/foot. The 24-inch driveway culverts are designed to convey the 10-year flow.

5.2 Ditches

A shared ditch between the parking lot and Riverland Drive will be established to provide drainage away from the paved section. Providing positive drainage away from the surfacing section will provide a longer design life for the pavement. Ditches were evaluated for capacity with respect to the requirement that the design peak flow water surface elevation be below the bottom of the parking lot base section.

5.3 Floodway

The trail was designed so that there was a balance of earth material along the trail alignment so that it results in a net zero fill within the floodway, which meets Shasta County floodway requirements where FEMA involvement would not be required. See earthwork balancing results in Appendix D. A floodway area analysis revealed that the location of the maximum trail fill along the alignment would create an approximate 0.5 percent blockage across the floodway, which is less than the 1 percent maximum blockage allowed by CVFPB. See analysis results in Appendix D. Work within the floodway meets the local government requirements.

6. Erosion and Sediment Control

6.1 Construction BMPs

Fiber roll, riprap or gravel bag check dams may be utilized in disturbed cut ditches and immediately upstream of existing and proposed culvert crossings to minimize the amount of sediment leaving the project within concentrated flows. Silt fencing or fiber rolls will be used at the base of disturbed slopes to minimize sediment leaving the project via sheet flow. To minimize soil tracking off the project site from vehicles, a stabilized construction exit will be used where construction traffic is leaving the disturbed area.

6.2 Permanent BMPs

Native seed and mulch mix will be used for permanent erosion control. Riprap or rolled erosion control product may be required along steeper side slopes of the ditches. Riprap will be installed at culvert outlets.

7. References

American Association of State Highway and Transportation Officials (AASHTO). 2011. A Policy on Geometric Design of Highways and Streets.

Federal Highway Administration (FHWA). July 2018. “Federal Lands Highway Project Development and Design Manual”, U.S. Department of Transportation, Washington, DC.

Federal Emergency Management Agency (FEMA). Flood Map Service Center.

https://msc.fema.gov/portal/home

State of California Central Valley Flood Protection Board (CVFPB). “Central Valley Flood Protection Board Permitting.” http://cvfpb.ca.gov/permitting/

U.S. Army Corps of Engineers Sacramento District. 2019. Categorical Permission Blockage Calculation Procedures. January.

Appendix A FEMA Floodplain Mapping

USGS The National Map: Orthoimagery. Data refreshed October 2017.

National Flood Hazard Layer FIRMette

0 500 1,000 1,500 2,000250 Feet

Ü

2°

'35

.55 "W

40°30'7.95"N

122°19'58.09"W

40°29'40.59"N

SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT

SPECIAL FLOOD

HAZARD AREAS

Without Base Flood Elevation (BFE) Zone A, V, A99

With BFE or Depth Zone AE, AO, AH, VE, AR Regulatory Floodway

0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mile Zone X Future Conditions 1% Annual Chance Flood Hazard Zone X Area with Reduced Flood Risk due to Levee. See Notes. Zone X Area with Flood Risk due to Levee Zone D

NO SCREEN Area of Minimal Flood Hazard Zone X

Area of Undetermined Flood Hazard Zone D

Channel, Culvert, or Storm Sewer Levee, Dike, or Floodwall

Cross Sections with 1% Annual Chance

17.5 Water Surface Elevation

Coastal Transect

Coastal Transect Baseline Profile Baseline Hydrographic Feature

Base Flood Elevation Line (BFE)

Effective LOMRs

Limit of Study Jurisdiction Boundary

Digital Data Available No Digital Data Available Unmapped

This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below.

The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 12/3/2018 at 5:34:20 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time.

This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes.

Legend

OTHER AREAS OF

FLOOD HAZARD

OTHER AREAS

GENERAL

STRUCTURES

OTHER

FEATURES

MAP PANELS

1:6,000

B 20.2

The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location.

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dstewar1 Highlight dstewar1 Highlight dstewar1 Callout Project Site dstewar1 Callout Downstream of Churn Creek dstewar1 Highlight dstewar1 Highlight

Table 6 - Summary of Discharges

Chance Chance Chance Chance

Sacramento River

Sacramento River

Moody Creek

Rancheria Creek

Churn Creek

At Barney Street 1.32 428 698 463 974

Below Battle Creek 8,800.00 131,000 219,000 281,000 525,000

Regulated by Shasta Dam

FLOODING SOURCE

AND LOCATION

DRAINAGE

AREA

(sq. miles)

PEAK DISCHARGES (cfs) 10% Annual 2% Annual 1% Annual 0.2% Annual

OLNEY CREEK

At Anderson Cottonwood 13.36 1 1 3,8802 1 Canal At Market Street (SH 273) 13.40 2,390 3,190 2 4,300 At Confluence with 14.70 3,000 4,750

3,490

5,600 7,700

OREGON GULCH

At Confluence with 3.50 700 920 1,000 1,200

RANCHERIA CREEK

Upstream of Rancheria Creek 0.89 450 690 780 950North Branch Downstream of Rancheria 2.12 1,000 1,600 1,900 2,300Creek North Branch Upstream of confluence with 2.13 1,000 1,600 1,900 2,300

RANCHERIA CREEK

NORTH BRANCH

Upstream of confluence with 1.22 650 1,100 1,200 1,500

RICH GULCH CREEK

Upstream of confluence with 0.67 300 500 570 710

3SACRAMENTO GULCH

At State Highwy 273 1.28 377 435 851 951

3SACRAMENTO RIVER

4At Keswick 6,498.00 79,000 79,000 79,000 318,000

Above Clear Creek 6,500.00 79,000 79,000 79,000 319,000 Above Churn Creek 6,800.00 88,000 102,000 112,000 351,000

1 Data not Available 2 Differences in 1% annual chance dishcarges due to different hydrologicl models used in the 1989 study (at Market St) and the 1994 study (at canal).

See Figure 1 - Frequency-Discharge, Drainage Area Curves

Appendix B Hydrologic Calculations

NOAA Atlas 14, Volume 6, Version 2 Location name: California, USA*

Latitude: 40.5004°, Longitude: -122.3404° Elevation: 432.22 ft**

* source: ESRI Maps ** source: USGS

POINT PRECIPITATION FREQUENCY ESTIMATES

Sanja Perica, Sarah Dietz, Sarah Heim, Lillian Hiner, Kazungu Maitaria, Deborah Martin, Sandra Pavlovic, Ishani Roy, Carl Trypaluk, Dale Unruh, Fenglin Yan, Michael Yekta, Tan Zhao, Geoffrey

Bonnin, Daniel Brewer, Li-Chuan Chen, Tye Parzybok, John Yarchoan

NOAA, National Weather Service, Silver Spring, Maryland

PF_tabular | PF_graphical | Maps_&_aerials

PF tabular

PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hour)1

Duration Average recurrence interval (years)

1 2 5 10 25 50 100 200 500 1000

5-min 2.62

(2.26-3.06) 3.07

(2.65-3.61) 3.72

(3.19-4.38) 4.28

(3.64-5.09) 5.09

(4.16-6.29) 5.75

(4.58-7.28) 6.46

(5.00-8.42) 7.24

(5.42-9.76) 8.36

(5.98-11.8) 9.30

(6.38-13.7)

10-min 1.87

(1.61-2.19) 2.20

(1.90-2.59) 2.67

(2.29-3.14) 3.07

(2.61-3.64) 3.65

(2.98-4.51) 4.12

(3.29-5.22) 4.63

(3.59-6.04) 5.19

(3.89-6.99) 5.99

(4.28-8.48) 6.67

(4.58-9.82)

15-min 1.51

(1.30-1.76) 1.78

(1.53-2.08) 2.15

(1.85-2.53) 2.47

(2.10-2.94) 2.94

(2.40-3.63) 3.32

(2.65-4.21) 3.73

(2.89-4.87) 4.18

(3.14-5.64) 4.84

(3.45-6.84) 5.38

(3.69-7.92)

30-min 1.02

(0.882-1.20) 1.20

(1.04-1.41) 1.46

(1.25-1.71) 1.67

(1.42-1.99) 1.99

(1.63-2.46) 2.25

(1.79-2.85) 2.53

(1.96-3.30) 2.83

(2.12-3.82) 3.27

(2.34-4.63) 3.64

(2.50-5.36)

60-min 0.719

(0.620-0.841) 0.847

(0.730-0.993) 1.02

(0.880-1.21) 1.18

(1.00-1.40) 1.40

(1.15-1.73) 1.58

(1.26-2.01) 1.78

(1.38-2.32) 1.99

(1.49-2.69) 2.30

(1.65-3.26) 2.56

(1.76-3.77)

2-hr 0.505

(0.436-0.591) 0.576

(0.497-0.676) 0.680

(0.584-0.799) 0.770

(0.656-0.916) 0.907

(0.742-1.12) 1.02

(0.816-1.30) 1.15

(0.892-1.50) 1.30

(0.972-1.75) 1.52

(1.08-2.15) 1.71

(1.17-2.51)

3-hr 0.396

(0.342-0.464) 0.449

(0.387-0.526) 0.525

(0.451-0.618) 0.593

(0.505-0.705) 0.696

(0.569-0.860) 0.784

(0.625-0.993) 0.881

(0.683-1.15) 0.992

(0.744-1.34) 1.16

(0.829-1.64) 1.31

(0.897-1.93)

6-hr 0.263

(0.227-0.308) 0.298

(0.256-0.349) 0.347

(0.298-0.408) 0.390

(0.332-0.464) 0.456

(0.373-0.563) 0.512

(0.408-0.648) 0.574

(0.445-0.748) 0.644

(0.483-0.868) 0.751

(0.536-1.06) 0.844

(0.579-1.24)

12-hr 0.168

(0.145-0.197) 0.196

(0.169-0.230) 0.234

(0.201-0.276) 0.267

(0.227-0.317) 0.312

(0.255-0.386) 0.349

(0.278-0.442) 0.388

(0.301-0.506) 0.430

(0.322-0.579) 0.489

(0.349-0.691) 0.537

(0.369-0.791)

24-hr 0.107

(0.095-0.124) 0.131

(0.115-0.152) 0.161

(0.142-0.188) 0.186

(0.162-0.218) 0.219

(0.185-0.265) 0.245

(0.203-0.301) 0.270

(0.219-0.340) 0.297

(0.235-0.382) 0.332

(0.253-0.445) 0.359

(0.265-0.496)

2-day 0.069

(0.060-0.079) 0.084

(0.073-0.097) 0.103

(0.091-0.120) 0.119

(0.104-0.139) 0.141

(0.119-0.170) 0.157

(0.130-0.193) 0.174

(0.141-0.219) 0.191

(0.151-0.247) 0.215

(0.164-0.288) 0.233

(0.172-0.322)

3-day 0.053

(0.046-0.061) 0.064

(0.056-0.074) 0.079

(0.069-0.092) 0.091

(0.079-0.106) 0.107

(0.091-0.130) 0.120

(0.100-0.148) 0.133

(0.108-0.167) 0.147

(0.116-0.189) 0.165

(0.126-0.221) 0.180

(0.133-0.248)

4-day 0.045

(0.039-0.052) 0.054

(0.047-0.063) 0.066

(0.058-0.077) 0.077

(0.067-0.090) 0.090

(0.077-0.109) 0.101

(0.084-0.124) 0.112

(0.091-0.141) 0.124

(0.098-0.159) 0.139

(0.106-0.186) 0.151

(0.112-0.209)

7-day 0.032

(0.028-0.037) 0.038

(0.034-0.044) 0.047

(0.041-0.055) 0.054

(0.047-0.063) 0.064

(0.054-0.077) 0.071

(0.059-0.088) 0.079

(0.064-0.099) 0.086

(0.068-0.111) 0.097

(0.074-0.129) 0.105

(0.077-0.145)

10-day 0.025

(0.022-0.029) 0.031

(0.027-0.036) 0.038

(0.033-0.044) 0.043

(0.038-0.051) 0.051

(0.043-0.062) 0.057

(0.047-0.070) 0.063

(0.051-0.079) 0.069

(0.054-0.088) 0.076

(0.058-0.102) 0.082

(0.061-0.114)

20-day 0.017

(0.015-0.019) 0.021

(0.018-0.024) 0.026

(0.022-0.030) 0.029

(0.026-0.034) 0.034

(0.029-0.042) 0.038

(0.032-0.047) 0.042

(0.034-0.053) 0.046

(0.036-0.059) 0.050

(0.038-0.067) 0.054

(0.040-0.074)

30-day 0.013

(0.012-0.016) 0.017

(0.015-0.019) 0.021

(0.018-0.024) 0.024

(0.021-0.028) 0.028

(0.023-0.033) 0.031

(0.025-0.038) 0.033

(0.027-0.042) 0.036

(0.029-0.047) 0.040

(0.030-0.053) 0.043

(0.031-0.059)

45-day 0.011

(0.010-0.013) 0.014

(0.012-0.016) 0.017

(0.015-0.020) 0.020

(0.017-0.023) 0.023

(0.019-0.028) 0.025

(0.021-0.031) 0.028

(0.022-0.035) 0.030

(0.024-0.038) 0.033

(0.025-0.044) 0.035

(0.025-0.048)

60-day 0.010

(0.009-0.011) 0.012

(0.011-0.014) 0.015

(0.013-0.018) 0.017

(0.015-0.020) 0.020

(0.017-0.024) 0.022

(0.018-0.027) 0.024

(0.020-0.030) 0.026

(0.020-0.033) 0.028

(0.021-0.038) 0.030

(0.022-0.041)

1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).

Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.

Please refer to NOAA Atlas 14 document for more information.

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Page 1 of 4Precipitation Frequency Data Server

9/9/2019https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=40.5004&lon=-122.3404&dat...

PF graphical

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Page 2 of 4Precipitation Frequency Data Server

Maps & aerials

Small scale terrain

Large scale terrain

Large scale map

3km

2mi

100km

60mi

100km

60mi

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US Department of Commerce National Oceanic and Atmospheric Administration

National Weather Service National Water Center

1325 East West Highway Silver Spring, MD 20910

Questions?: HDSC.Questions@noaa.gov

Disclaimer

100km

60mi

Page 4 of 4Precipitation Frequency Data Server

Sacramento Island Trail Parking Lot North Culvert/Ditch Hydrologic Calculation Rational Method

Area Tributary to Ditch (Area estimated from Google Earth) Length = 914 ft Width = 150 ft Assumed velocity = 3.0 fps Area 137,100 sq. ft.

Area (A) 3.15 ac

Time of Concentration and Intensity TOC 5.1 min Tc i10

Intensity (i10) 4.26 in/hr 10-year 5 4.28

5.1 x 10 3.07

Weighted Runoff Coefficient Pavement Grass

0.9 0.4 13,710 123,390

Cw 0.45

10-year Runoff Q = Cwi10A Q10 6.0 cfs

Parking Lot South Culvert/Ditch Hydrologic Calculation Rational Method

Area Tributary to Ditch (Area estimated from Google Earth) Length = 1400 ft Width = 150 ft Assumed velocity = 3.0 fps Area 210,000 sq. ft.

Area (A) 4.82 ac

Time of Concentration and Intensity TOC 7.8 min Tc i10

Intensity (i10) 3.61 in/hr 10-year 5 4.28

7.8 x 10 3.07

Weighted Runoff Coefficient Pavement Grass

0.9 0.4 21,000 189,000

Cw 0.45

10-year Runoff Q = Cwi10A Q10 7.8 cfs

Appendix C Hydraulic Calculations

HY-8 Culvert Analysis Report

Crossing Discharge Data

Discharge Selection Method: Specify Minimum, Design, and Maximum Flow Minimum Flow: 0 cfs Design Flow: 6 cfs Maximum Flow: 10 cfs

North Culvert

Table 1 - Summary of Culvert Flows at Crossing: North Culvert Headwater Elevation (ft)Total Discharge (cfs)Culvert 1 Discharge

(cfs) Roadway Discharge

(cfs) Iterations

10.50 0.00 0.00 0.00 1

11.03 1.00 1.00 0.00 1

11.27 2.00 2.00 0.00 1

11.45 3.00 3.00 0.00 1

11.62 4.00 4.00 0.00 1

11.77 5.00 5.00 0.00 1

11.91 6.00 6.00 0.00 1

12.04 7.00 7.00 0.00 1

12.17 8.00 8.00 0.00 1

12.31 9.00 9.00 0.00 1

12.44 10.00 10.00 0.00 1

14.00 17.15 17.15 0.00 Overtopping

Rating Curve Plot for Crossing: North Culvert

Table 2 - Culvert Summary Table: Culvert 1 Total

Discharg e (cfs)

Culvert Discharg e (cfs)

Headwate r

Elevation (ft)

Inlet Control Depth (ft)

Outlet Control Depth (ft)

Flow Type

Normal Depth (ft)

Critical Depth (ft)

Outlet Depth (ft)

Tailwater Depth (ft)

Outlet Velocity

(ft/s)

Tailwater Velocity

(ft/s)

0.00 0.00 10.50 0.000 0.000 0-NF 0.000 0.000 0.000 0.000 0.000 0.000

1.00 1.00 11.03 0.491 0.532 3-M1t 0.404 0.340 0.656 0.656 1.114 1.160

2.00 2.00 11.27 0.702 0.767 3-M1t 0.573 0.485 0.851 0.851 1.569 1.380

3.00 3.00 11.45 0.869 0.954 3-M1t 0.709 0.601 0.991 0.991 1.932 1.527

4.00 4.00 11.62 1.014 1.117 3-M1t 0.829 0.697 1.104 1.104 2.249 1.641

5.00 5.00 11.77 1.151 1.267 3-M1t 0.941 0.783 1.200 1.200 2.540 1.735

6.00 6.00 11.91 1.275 1.407 3-M1t 1.049 0.865 1.285 1.285 2.812 1.816

7.00 7.00 12.04 1.390 1.543 3-M1t 1.156 0.939 1.362 1.362 3.073 1.887

8.00 8.00 12.17 1.500 1.674 3-M1t 1.264 1.006 1.432 1.432 3.324 1.951

9.00 9.00 12.31 1.610 1.805 3-M1t 1.378 1.069 1.496 1.496 3.570 2.010

10.00 10.00 12.44 1.721 1.938 3-M1t 1.506 1.126 1.557 1.557 3.812 2.063

Straight Culvert

Inlet Elevation (invert): 10.50 ft, Outlet Elevation (invert): 10.00 ft

Culvert Length: 67.00 ft, Culvert Slope: 0.0075

Culvert Performance Curve Plot: Culvert 1

Water Surface Profile Plot for Culvert: Culvert 1

Site Data - Culvert 1 Site Data Option: Culvert Invert Data Inlet Station: 0.00 ft Inlet Elevation: 10.50 ft Outlet Station: 67.00 ft Outlet Elevation: 10.00 ft Number of Barrels: 1

Culvert Data Summary - Culvert 1 Barrel Shape: Circular Barrel Diameter: 2.00 ft Barrel Material: Corrugated Steel Embedment: 0.00 in Barrel Manning's n: 0.0240 Culvert Type: Straight Inlet Configuration: Mitered to Conform to Slope Inlet Depression: None

Table 3 - Downstream Channel Rating Curve (Crossing: North Culvert) Flow (cfs) Water Surface

Elev (ft) Depth (ft) Velocity (ft/s) Shear (psf) Froude Number

0.00 10.00 0.00 0.00 0.00 0.00

1.00 10.66 0.66 1.16 0.20 0.36

2.00 10.85 0.85 1.38 0.27 0.37

3.00 10.99 0.99 1.53 0.31 0.38

4.00 11.10 1.10 1.64 0.34 0.39

5.00 11.20 1.20 1.74 0.37 0.39

6.00 11.29 1.29 1.82 0.40 0.40

7.00 11.36 1.36 1.89 0.42 0.40

8.00 11.43 1.43 1.95 0.45 0.41

9.00 11.50 1.50 2.01 0.47 0.41

10.00 11.56 1.56 2.06 0.49 0.41

Tailwater Channel Data - North Culvert Tailwater Channel Option: Triangular Channel Side Slope (H:V): 2.00 (_:1) Channel Slope: 0.0050 Channel Manning's n: 0.0400 Channel Invert Elevation: 10.00 ft

Roadway Data for Crossing: North Culvert Roadway Profile Shape: Constant Roadway Elevation Crest Length: 50.00 ft Crest Elevation: 14.00 ft Roadway Surface: Paved Roadway Top Width: 24.00 ft

Discharge Selection Method: Specify Minimum, Design, and Maximum Flow Minimum Flow: 0 cfs Design Flow: 7.8 cfs Maximum Flow: 10 cfs

South Culvert

Table 1 - Summary of Culvert Flows at Crossing: South Culvert Headwater Elevation (ft)Total Discharge (cfs)Culvert 1 Discharge

(cfs) Roadway Discharge

(cfs) Iterations

10.25 0.00 0.00 0.00 1

10.82 1.00 1.00 0.00 1

11.07 2.00 2.00 0.00 1

11.26 3.00 3.00 0.00 1

11.43 4.00 4.00 0.00 1

11.58 5.00 5.00 0.00 1

11.72 6.00 6.00 0.00 1

11.84 7.00 7.00 0.00 1

11.97 7.80 7.80 0.00 1

12.13 9.00 9.00 0.00 1

12.26 10.00 10.00 0.00 1

14.00 18.46 18.46 0.00 Overtopping

Rating Curve Plot for Crossing: South Culvert

Total

Discharg e (cfs)

Culvert Discharg e (cfs)

Headwate r

Elevation (ft)

Inlet Control Depth (ft)

Outlet Control Depth (ft)

Flow Type

Normal Depth (ft)

Critical Depth (ft)

Outlet Depth (ft)

Tailwater Depth (ft)

Outlet Velocity

(ft/s)

Tailwater Velocity

(ft/s)

0.00 0.00 10.25 0.000 0.000 0-NF 0.000 0.000 0.000 0.000 0.000 0.000

1.00 1.00 10.82 0.490 0.569 3-M1t 0.446 0.340 0.656 0.656 1.114 1.160

2.00 2.00 11.07 0.700 0.818 3-M1t 0.636 0.485 0.851 0.851 1.569 1.380

3.00 3.00 11.26 0.866 1.012 3-M1t 0.790 0.601 0.991 0.991 1.932 1.527

4.00 4.00 11.43 1.011 1.180 3-M1t 0.929 0.697 1.104 1.104 2.249 1.641

5.00 5.00 11.58 1.148 1.332 3-M1t 1.061 0.783 1.200 1.200 2.540 1.735

6.00 6.00 11.72 1.271 1.475 3-M1t 1.191 0.865 1.285 1.285 2.812 1.816

7.00 7.00 11.84 1.386 1.591 3-M1t 1.326 0.939 1.362 1.362 3.073 1.887

7.80 7.80 11.97 1.475 1.716 3-M2t 1.443 0.994 1.418 1.418 3.274 1.939

9.00 9.00 12.13 1.606 1.877 3-M2t 2.000 1.069 1.496 1.496 3.570 2.010

10.00 10.00 12.26 1.717 2.010 3-M2t 2.000 1.126 1.557 1.557 3.812 2.063

Inlet Elevation (invert): 10.25 ft, Outlet Elevation (invert): 10.00 ft

Culvert Length: 50.00 ft, Culvert Slope: 0.0050

Site Data Option: Culvert Invert Data Inlet Station: 0.00 ft Inlet Elevation: 10.25 ft Outlet Station: 50.00 ft Outlet Elevation: 10.00 ft Number of Barrels: 1

Culvert Data Summary - Culvert 1 Barrel Shape: Circular Barrel Diameter: 2.00 ft Barrel Material: Corrugated Steel Embedment: 0.00 in Barrel Manning's n: 0.0240 Culvert Type: Straight Inlet Configuration: Mitered to Conform to Slope

Table 3 - Downstream Channel Rating Curve (Crossing: South Culvert )

Elev (ft) Depth (ft) Velocity (ft/s) Shear (psf) Froude Number

0.00 10.00 0.00 0.00 0.00 0.00

1.00 10.66 0.66 1.16 0.20 0.36

2.00 10.85 0.85 1.38 0.27 0.37

3.00 10.99 0.99 1.53 0.31 0.38

4.00 11.10 1.10 1.64 0.34 0.39

5.00 11.20 1.20 1.74 0.37 0.39

6.00 11.29 1.29 1.82 0.40 0.40

7.00 11.36 1.36 1.89 0.42 0.40

7.80 11.42 1.42 1.94 0.44 0.41

9.00 11.50 1.50 2.01 0.47 0.41

10.00 11.56 1.56 2.06 0.49 0.41

Tailwater Channel Data - South Culvert Tailwater Channel Option: Triangular Channel Side Slope (H:V): 2.00 (_:1) Channel Slope: 0.0050 Channel Manning's n: 0.0400 Channel Invert Elevation: 10.00 ft

Roadway Data for Crossing: South Culvert Roadway Profile Shape: Constant Roadway Elevation Crest Length: 50.00 ft Crest Elevation: 14.00 ft

Roadway Top Width: 24.00 ft

Project Description

Friction Method Manning Formula

Solve For Normal Depth

Input Data

Roughness Coefficient 0.040

Channel Slope 0.00500 ft/ft

Left Side Slope 2.00 ft/ft (H:V)

Right Side Slope 2.00 ft/ft (H:V)

Discharge 7.80 ft³/s

Results

Normal Depth 1.42 ft

Flow Area 4.02 ft²

Wetted Perimeter 6.34 ft

Hydraulic Radius 0.63 ft

Top Width 5.67 ft

Critical Depth 0.99 ft

Critical Slope 0.03421 ft/ft

Velocity 1.94 ft/s

Velocity Head 0.06 ft

Specific Energy 1.48 ft

Froude Number 0.41

Flow Type Subcritical

GVF Input Data

Downstream Depth 0.00 ft

Length 0.00 ft

Number Of Steps 0

GVF Output Data

Upstream Depth 0.00 ft

Profile Description

Profile Headloss 0.00 ft

Downstream Velocity Infinity ft/s

Upstream Velocity Infinity ft/s

Normal Depth 1.42 ft

Critical Depth 0.99 ft

Channel Slope 0.00500 ft/ft

Critical Slope 0.03421 ft/ft

Worksheet for South V-Ditch

9/17/2020 8:20:08 AM

Bentley Systems, Inc. Haestad Methods Solution CenterBentley FlowMaster V8i (SELECTseries 1) [08.11.01.03]

27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 2of1Page

Messages

Notes

Conservatively assuming both side slopes are 1:2 to determine greatest depth. Actual side slopes vary from 1:2 to 1:8.

Worksheet for South V-Ditch

9/17/2020 8:20:08 AM

Bentley Systems, Inc. Haestad Methods Solution CenterBentley FlowMaster V8i (SELECTseries 1) [08.11.01.03]

27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 2of2Page

Discharge Selection Method: User Defined

Riverland Culvert

Table 1 - Summary of Culvert Flows at Crossing: Riverland Culvert Headwater Elevation (ft)

Discharge NamesTotal Discharge (cfs)

Culvert 1 Discharge (cfs)

Roadway Discharge (cfs)

Iterations

430.50 44 44.00 44.00 0.00 1

431.07 51.8 51.80 51.80 0.00 1

431.50 Overtopping 56.90 56.90 0.00 Overtopping

Rating Curve Plot for Crossing: Riverland Culvert

Discharg e Names

Total Discharg e (cfs)

Culvert Discharg e (cfs)

Headwate r

Elevation (ft)

Inlet Control Depth (ft)

Outlet Control Depth (ft)

Flow Type

Normal Depth (ft)

Critical Depth (ft)

Outlet Depth (ft)

Tailwater Depth (ft)

Outlet Velocity

(ft/s)

Tailwater Velocity

(ft/s)

44 44.00 44.00 430.50 3.555 2.918 5-S2n 1.826 2.158 1.949 1.697 8.787 1.684

51.8 51.80 51.80 431.07 4.131 3.834 5-S2n 2.052 2.338 2.164 1.860 9.229 1.772

Inlet Elevation (invert): 426.94 ft, Outlet Elevation (invert): 426.65 ft

Culvert Length: 40.00 ft, Culvert Slope: 0.0073

Site Data Option: Culvert Invert Data Inlet Station: 0.00 ft Inlet Elevation: 426.94 ft Outlet Station: 40.00 ft Outlet Elevation: 426.65 ft Number of Barrels: 1

Culvert Data Summary - Culvert 1 Barrel Shape: Circular Barrel Diameter: 3.00 ft Barrel Material: Concrete Embedment: 0.00 in Barrel Manning's n: 0.0120 Culvert Type: Straight Inlet Configuration: Square Edge with Headwall

Table 3 - Downstream Channel Rating Curve (Crossing: Riverland Culvert)

Elev (ft) Depth (ft) Velocity (ft/s) Shear (psf) Froude Number

44.00 428.35 1.70 1.68 0.15 0.25

51.80 428.51 1.86 1.77 0.16 0.25

Tailwater Channel Data - Riverland Culvert Tailwater Channel Option: Trapezoidal Channel Bottom Width: 12.00 ft Side Slope (H:V): 2.00 (_:1) Channel Slope: 0.0014 Channel Manning's n: 0.0400 Channel Invert Elevation: 426.65 ft

Roadway Data for Crossing: Riverland Culvert Roadway Profile Shape: Constant Roadway Elevation Crest Length: 50.00 ft Crest Elevation: 431.50 ft

Roadway Top Width: 26.00 ft

Project Description

Friction Method Manning Formula

Solve For Normal Depth

Input Data

Roughness Coefficient 0.040

Channel Slope 0.00140 ft/ft

Left Side Slope 2.00 ft/ft (H:V)

Right Side Slope 2.00 ft/ft (H:V)

Bottom Width 12.00 ft

Discharge 51.80 ft³/s

Results

Normal Depth 1.86 ft

Flow Area 29.24 ft²

Wetted Perimeter 20.32 ft

Hydraulic Radius 1.44 ft

Top Width 19.44 ft

Critical Depth 0.80 ft

Critical Slope 0.02697 ft/ft

Velocity 1.77 ft/s

Velocity Head 0.05 ft

Specific Energy 1.91 ft

Froude Number 0.25

Flow Type Subcritical

GVF Input Data

Downstream Depth 0.00 ft

Length 0.00 ft

Number Of Steps 0

GVF Output Data

Upstream Depth 0.00 ft

Profile Description

Profile Headloss 0.00 ft

Downstream Velocity Infinity ft/s

Upstream Velocity Infinity ft/s

Normal Depth 1.86 ft

Critical Depth 0.80 ft

Channel Slope 0.00140 ft/ft

Worksheet for Trapezoidal Channel - 1

9/24/2020 7:57:43 AM

Bentley Systems, Inc. Haestad Methods Solution CenterBentley FlowMaster V8i (SELECTseries 1) [08.11.01.03]

27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 2of1Page

Worksheet for Trapezoidal Channel - 1 GVF Output Data

Critical Slope 0.02697 ft/ft

9/24/2020 7:57:43 AM

Bentley Systems, Inc. Haestad Methods Solution CenterBentley FlowMaster V8i (SELECTseries 1) [08.11.01.03]

27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 2of2Page

Appendix D Floodway Area Analyses

Triangle Volume Report Report Created: 9/24/2020

Time: 11:43am

Mode: Fence Input Grid Factor: 1.000000

Original Surface: Original Topo Description: Description Preference: Default

Type: Existing Design Surface: BP

Description: Created from roadway designer Preference: Default

Type: Design Cut Factor: 1.00 Fill Factor: 1.00

Cut: 4498.0 cu ft Fill: 15678.7 cu ft Net: -11180.8 cu ft

Cut: 166.6 cu yd Fill: 580.7 cu yd Net: -414.1 cu yd

Original Surface: Original Topo Description: Description Preference: Default

Type: Existing Design Surface: VolMitigationGrading_SouthCut

Description:

Preference: Default

Type: Existing Cut Factor: 1.00 Fill Factor: 1.00

Cut: 8393.7 cu ft Fill: 0.0 cu ft Net: 8393.7 cu ft

Cut: 310.9 cu yd Fill: 0.0 cu yd Net: 310.9 cu yd

Page 1 of 1Triangle Volume Report

9/24/2020file:///C:/Users/nl058442/AppData/Local/Temp/InRoadsReport.htm

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Triangle Volume Report Report Created: 9/24/2020

Time: 11:39am

Mode: Entire Surface Input Grid Factor: 1.000000

Original Surface: Original Topo Description: Description Preference: Default

Type: Existing Design Surface: VolumetricMitigationGrading_NorthCut

Description:

Preference: Default

Type: Existing Cut Factor: 1.00 Fill Factor: 1.00

Cut: 6934.9 cu ft Fill: 35.3 cu ft Net: 6899.6 cu ft

Cut: 256.8 cu yd Fill: 1.3 cu yd Net: 255.5 cu yd

Page 1 of 1Triangle Volume Report

9/24/2020file:///C:/Users/nl058442/AppData/Local/Temp/InRoadsReport.htm

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Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community

0 1,000500 Feet́

Approx. FEMA Floodway (per above FEMA Plan View)

Area = 14,390 Sq. Ft.

427.6

Cross-Section V

430� r T T T

425 ----+== ---- -- 425 j

77.5 SF

420--+-- -- 420 j

41+50 i i t j j j j i i f 415 415- -70 -60 -so -40 -30 -20 -10 0 10 20 30 40 50 60 70

Maximum fill along trail

Appendix E Site Photos

TR1011161141BOI 7-1

Appendix E Site Photos

Sacramento Island Trail - Photos

Trailhead Near Parking Lot – Looking North

Culvert Under Riverland Drive

Barrier downstream of road culvert

Ditch between Riverland Drive and trail

Trailhead Near Parking Lot – Looking South

Existing trail near future parking area

Existing trail near future parking area

Existing trail

Existing trail

View from existing trail

Existing trail

Existing trail

Existing trail

View from existing trail

View from existing trail

Existing trail

Existing trail

Existing trail

Sacramento River adjacent to existing trail

Sacramento River adjacent to existing trail

Existing trail

Sign along existing trail

Bench along existing trail

Existing trail

Existing trail

View from existing trail

Existing trail

Sacramento River adjacent to existing trail

Existing trail

View from existing trail

Sign along existing trail

End of Trail

Signs near Parking Lot

View near future parking area

Access to future parking area

Existing features near future parking area

View near future parking area

View near future parking area

View near future parking area

Barrier downstream of roadway culvert

Existing Access from Riverland Drive

Access on the left and trail on the right

Appendix F Field Report

U.S. DEPARTMENT OF TRANSPORTATION

FEDERAL HIGHWAY ADMINISTRATION

MEETING REPORT

REGION

Redding, CA

REPORT ON: Sacramento Island Trailhead

30% Meeting & Field Review

DIVISION:

CFLHD

DATE:

10/29/2019

ATTENDEES:

See Below

PROJECT NO.:

CA FLAP

RED 2017(3)

Federal Highway Administration (FHWA), Central Federal Lands Division (CFLHD) Matt Ambroziak, Project Manager

Jacobs, A/E consultant for CFLHD Ed Henderson, A/E Project Manager Travis Howard, Design Manager Nicole Lapp, Trail Design Lead Ashley Kellogg, Parking Lot Design Lead

City of Redding, Community Services Travis Menne, Community Projects Manager

Shasta County, Public Works Josh Cannan, Floodplain Manager William Miller, Engineering Don Renz, Encroachment Permits

California Fish and Wildlife Services Adam McKannay

Action items are captured throughout this document in bold italics and also summarized at the end in the action register.

Decisions are captured throughout this document in bold underline and also summarized at the end of the action register.

ONSITE 30% SUBMITTAL REVIEW MEETING

1. Project Overview:

a) Self-introductions

b) Agenda overview (meeting and site visit)

c) CFLHD project delivery and construction management overview

d) Federal Lands Access Program overview. Construction funding available Fiscal Year

2020.

e) Project schedule milestones:

• 30% Design submitted in October 2019

• NEPA completion in November/December 2019

• 95% Design submittal: Spring 2019

• 100% Design submittal: Summer 2020

• Advertise Construction: Fall/Winter 2020/2021

• Construction: Summer 2021

Estimate:

a) Discussed overall project budget relative to what’s programmed. CFLHD communicated that they could cover minor increases, but the City would still need to come up with an 11.47% match.

b) City and CFLHD were comfortable with the current EE and did not see a need to cut scope at this time. Additionally, scope adds, such as solar lighting and a shade structure are going to be considered, with an understanding that the project cost will increase.

c) CFLHD requested partnering be added into the EE. Jacobs will add partnering to the EE for the 90 percent submittal.

d) Due to the relatively shallow excavations and high quality of the native soil from a planting perspective, Jacobs will eliminate bid items for conserve and stockpile topsoil and placement of topsoil. This won’t impact the design or overall earthwork quantities, but will reduce the amount of material handling, which should result in a cost savings.

Seeding will be applied to finished cuts and fills without advanced placement of topsoil.

e) Items such as the restroom, bollards, solar lights, and shade structure will most likely be off the shelf items with a preferred manufacturer. CFLHD to provide Jacobs with their preference on how items with a single manufacturer should be bid.

2. County Coordination Items:

a) County had no comments on parking lot design. Driveways as shown are acceptable.

b) County was ok with a guide sign to be placed within their right-of-way north of the parking lot entrance notifying potential users of the upcoming driveway. City to provide desired message for guide sign north of parking lot entrance.

c) Schedule of County road widening project relative to Sac Island project discussed.

Definitive timing of County project is unknown. It was decided that the Sac Island Project should design around the future widening, but the construction package should be put together as if the widening project is constructed after the Sac Island Project. This will result in additional paving at driveway conforms, and additional riprap and grading at the existing culvert outlet. County to provide the latest set of plans for their widening project.

d) County was satisfied with the proposed drainage ditch that will be receiving flows from the existing 36” RCP that is discharging from the County Right of Way into the project area. The project team walked the proposed ditch alignment and also reviewed against the adjacent property line. Both of which were staked in the field.

e) Future County widening will be shown on plan only, but not on cross sections. Grading from parking lot construction may encroach into the county Right of Way. This grading will be rolled into the encroachment permit for the driveways.

3. Floodplain/Floodway:

a) Discussed hydraulics memo. Josh Cannan provided clarifying comments with regards to the analysis methods used. Although the CVFPB required the 1% blockage analysis outlined in the memo, that would not satisfy the requirements needed for approval by the Shasta County Floodplain administrator.

b) It was recommended that the team perform a cut/fill analysis within the portion of the project inside the floodway to demonstrate no increase in flood elevation.

c) Providing localized excavations adjacent to the path within the floodway were deemed acceptable, if necessary, to create a project that had no net fill within the floodway.

d) The property line along the eastern edge of the proposed drainage ditch will be confirmed by Jacobs survey team and incorporated into the drawings. The City to provide the property boundary description for their parcel.

4. Parking Lot:

a) Overall parking lot design was acceptable by County, City, and CFLHD. Key items agreed upon were number of stalls, driveway locations and landscaping concept.

b) Proposed restroom location was acceptable

c) The city would like solar lighting incorporated into the project. The city to provide information on details/specs/cost data and preferred location of lights within the parking lot.

d) The city would like to incorporate a shade structure into the project. Two potential locations are shown on the consolidated redlines. The city to provide information on details/specs/cost data and preferred location of shade structure within the parking lot.

e) Landscaping can be irrigated with well water available onsite from the City’s tenant. A stub-out onsite has been identified. The City to provide pressure and flow information for the waterline.

f) All salvageable materials removed during construction need to be salvaged for use by the City. These include items such as gates, k-rail, fencing, and signs.