CFLHD_NM_FLAP_52000(1)_100__Drainage_Report_signedsealed.pdf

nd

Street Southwest Corridor Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000(1) / Final Drainage

Recommendations Report

Street Southwest Corridor

Valle de Oro National Wildlife Refuge

NM FLAP 52000(1)

Final Drainage

Federal Highway Administration

Central Federal Lands Highway Division

Prepared by

HDR Engineering, Inc.

August 18, 2017

08/24/2017

Street Southwest Corridor Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

TABLE OF CONTENTS

Page

1. INTRODUCTION

1.1. Scope and Purpose

1.2. Project Location

1.3. Project Description

1.4. Drainage Criteria

2. HYDROLOGY

2.1 Drainage Basin Descriptions

2.2 Prediction of Design Discharge

2.2.1 Simplified Peak Flow Method

2.2.2 Existing Studies

2.2.3 FEMA

3. DESIGN DISCUSSION

3.1. Design Criteria

3.2. Existing Structures

3.3. Hydraulic Analysis

3.3.1. Roadway Drainage

3.3.2. Culvert Design

4. RECOMMENDED DESIGN

4.1. Roadway Drainage

4.2. Culverts

4.3. Ditches

4.4. Irrigation

4.5. Water Quality

5. SUMMARY

6. REFERENCES

APPENDIX A – DESIGN CRITERIA MEMO ............................................................................................... I

APPENDIX B – HYDROLOGY ................................................................................................................ II

APPENDIX C – FEMA .......................................................................................................................... III

APPENDIX D – HYDRAULICS .............................................................................................................. IV

Street Southwest Corridor Central Federal Lands Highway Division

APPENDIX E – WATER QUALITY ......................................................................................................... V

APPENDIX F – PHOTO LOG ................................................................................................................ VI

Street Southwest Corridor 1 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report

1. INTRODUCTION

1.1. Scope and Purpose

This report summarizes the hydrologic and hydraulic analyses performed for the 2

Street Southwest Corridor, project number NM FLAP 52000(1), located near

Albuquerque, in Bernalillo County, New Mexico and provides access to the Valle de Oro

National Wildlife Refuge.

The drainage design for this project was prepared in accordance with Bernalillo County;

City of Albuquerque “Albuquerque Development Process Manual” Chapter 22 Drainage, Flood Control and Erosion Control, March 1982; and the Federal Lands Highway “Project

Development and Design Manual”, Hydrology and Hydraulics Chapter, December 2012.

1.2. Project Location

The 2nd Street Southwest (SW) corridor is located west of Interstate 25 (I-25) and east of the Rio Grande River between Salida Sandia SW/ Valle de Oro National Wildlife

Refuge on the south and South Diversion Channel on the north.

Figure 1. Location Map

Street Southwest Corridor 2 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report

1.3. Project Description

2nd Street is an urban paved two lane collector and minor arterial roadway that serves a residential and industrial area, and visitors to the Refuge. The project has been broken into two segments.

Segment 1 is a planned local street located on the south side of the project anticipated to be a rural section leading from the Refuge (Station 47+00) to the intersection of

Desert Road (Station 85+00). This segment of the road has low traffic volumes. From

Station 47+00 to Station 81+75 the roadway section is a 24 foot paved section, aggregate shoulder and 12 foot multimodal trail. From Station 81+75 to 84+30 the roadway section is 22 foot traveled way, 5 foot paved shoulder and 12 foot multimodal trail. There are two irrigation structures that cross and canals that run adjacent to 2nd

Street.

Segment 2 is a planned urban collector from Desert Road (Station 85+00) to South

Diversion Channel (Station 127+50). The roadway section on the west is residential and includes a 5 foot sidewalk with curb and gutter, 10 foot turn lane and 11 foot traveled way. The east side includes an 11 foot traveled way, 3 foot shoulder, curb and gutter, 8 foot landscape buffer and 12 foot multimodal trail. This segment also includes the reconstruction of Desert Road intersection.

2nd Street is located within flat terrain just west of the Rail Runner high speed rail line.

The ADT is projected at 500 ADT for segment 1 and 12,800 for segment 2 in the design year of 2034. The posted speed varies between 35, 40 and 45 miles per hour.

The general scope of roadway improvements is programmed as pulverize and reclaim the existing pavement and portion of the existing subgrade for use as a new base course and overlay with a new asphalt concrete pavement section as well as widening for additional turn lanes and a 12 foot wide multi-modal trail for 5.5 miles of 2nd Street SW.

Included in the project are segments of milling and overlay with widening, curb and gutter, intersection improvement, utility relocation, drainage infrastructure, pedestrian bridge and Right of Way acquisitions. Guardrails are also to be upgraded to meet standards.

There currently are no curb and gutter sections or drainage systems within the project.

There are two irrigation structures between the Refuge and Desert Road and an existing drainage structure at Desert Road. The area has known flooding concerns and the culvert at Desert Road is significantly undersized. Bernalillo County is part of a regional master plan that includes this area in its study. The Barr Main Canal crosses 2 nd

Street

South of Desert Road.

Drainage improvements for the purposes of 2nd Street will be addressed in the project.

Proposed drainage improvements in the regional Stormwater Management Plan (SMP)

Street Southwest Corridor 3 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report prepared by Wilson & Company were evaluated during the preliminary design. These include upstream storm systems between Broadway Boulevard and 2 nd

Street and channel improvements downstream of the Desert Road culvert. These were evaluated during preliminary design and upstream systems are outside the scope of this project.

Albuquerque Metropolitan Arroyo Flood Control Authority (AMAFCA) is currently working on channel improvements downstream of Desert Road beginning at Barr Road that will convey flow to the Refuge.

1.4. Drainage Criteria

The 2nd Street project is located within Bernalillo County and funding from Federal

Highway Administration (FHWA), Central Federal Lands Highway Division (CFLHD) through the Federal Lands Access Program (FLAP). Both criteria will be followed, but will be primarily based on Bernalillo County Criteria. Drainage requirements for Bernalillo

County are based on the procedures outlined in the “City of Albuquerque’s

Development Process Manual” (DPM) Chapter 22, Drainage, Flood Control and Erosion

Control. Exceptions to the Bernalillo County criteria will defer to the FHWA “Project

Development and Procedure Manual” (PDDM). A summary of drainage design criteria can be found in Appendix A.

2. HYDROLOGY

2.1 Drainage Basin Descriptions

The project location has been previously studied in a regional Stormwater Management

Plan (SMP) with participation from Bernalillo County and has provided the major drainage basins contributing to the site. The “Southeast Valley Drainage and Stormwater Quality

Management Plan”, Wilson and Company, June 2012 has provided hydrology for offsite flows to the Desert Road existing culvert crossing, existing culvert analysis and proposed alternatives. The project area is located in the Far Southeast Valley Watershed and drains toward 2 nd

Street from east to west from the Mesa Top east of I-25 toward the Refuge.

Local roadway basins were delineated with project topography.

The area is located within an arid region with little vegetation. Vegetation and percent coverage is determined using aerial photography and site photos. Soil types and classifications are determined using the United States Department of Agriculture (USDA)

National Resources Conservation Service (NRCS) Web Soil Survey for Bernalillo County and parts of Sandoval and Valencia Counties, New Mexico. The hydrologic soil groups found for the area vary from Type A, B and C soils with fine sandy loams, Gila complex, and Glendale loam soils. The site is 1% Type A, 19% Type B, and 80% Type C soils. The terrain is flat without well defined roadside swales and intersection of irrigation canals. Irrigation canals that intersect the watershed include: Barr Main Canal, Barr Interior Drain and Albuquerque

Riverside Drain. The major basin draining toward 2 nd

Street overall drains east to west and slopes from 1 to 15% with the least grade change surrounding the project area, 0 to 4%. The

Street Southwest Corridor 4 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report existing drainage basin map from the SMP is included for reference (Figure 3-7) in Appendix

B. The area east of 2 nd

Street consists primarily of industrial development and to the west of nd street is a combination of residential and agricultural land uses. North of Desert Road is primarily urban and south of Desert Road is rural. The Far Southeast Valley Watershed is broken into six sub-basins, also identified on Figure 3-7. Sub-basin 1, which is 937 acres, contributes to the existing culvert located at Desert Road. Flooding within the watershed is common because of undersized channels, canals and culvert crossings.

The Existing Offsite Basin Map developed for the SMP and the delineated roadway basin areas are presented in Appendix B. Also included is the Valle de Oro Wildlife Refuge

Drainage from the Valle de Oro National Wildlife Refuge Site Plan Report, AMAFCA, March

2015.

2.2 Prediction of Design Discharge

2.2.1 Simplified Peak Flow Method

The Simplified Peak Flow Method in the DPM Section 2, Part A Procedure for 40 Acre and Smaller Basins was used to compute peak flows for onsite drainage areas that include roadway basins along the corridor. The simplified method was developed based on initial abstractions/uniform infiltration precipitation losses and Rational Method procedures. Based on Table A-1, Precipitation Zones and Figure A-1 (map), 2 nd

Street is located in Zone 2 of Bernalillo County. The 1-hour, 100-year rainfall depth is 2.01 inches.

This reference is included in Appendix B. The principal design storm is the 100-year 6-hour event defined by the NOAA Atlas 2, Precipitation-Frequency Atlas of the Western

United States, Volume IV – New Mexico, assuming an AMC II condition (a normally dry watershed).

Based on Table A-4, Land Treatments, land conditions for the project were identified as

Treatment C and D. Land treatment C includes areas of soil compacted by human activity, minimal vegetation, unpaved roads (railroad), native grasses, weeds and shrubs. This area is located between the east edge of trail and the center line of railroad.

Treatment D is described as impervious areas, pavement and roofs. This will include the roadway, sidewalks and trail. Table A-4, Land Treatments is included in Appendix B.

Peak discharges were calculated using Table A-9, Peak Discharge (cfs/acre) based on the

Zone and Land treatment. This table was developed based on a 0.2-hour (12 minute) time of concentration, peak discharge (Qp) per acre is the volume of excess precipitation in the heaviest 12 minute portion of the storm, divided by the time increment 12 minutes and multiplied by the attenuation factor. Section A.6 Peak

Discharge Rate for Small Watersheds is included in Appendix B.

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Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report

To determine peak discharge rate multiply each treatment by the respective basin area and sum to compute the total QP.

Total QP = QPAAA + QPBAB + QPCAC + QPDAD (equation a-10, City of Albuquerque

(COA))

Table 1 – DPM Table A-9 Peak Discharge (cfs/acre)

Zone Treatment

2 A B C D

2-year 0.00 0.08 0.60 1.86

10-year 0.38 0.95 1.71 3.14

100-year 1.56 2.28 3.14 4.70

Basin maps are included in Appendix B to show roadway basins between Valle de Oro

National Wildlife Refuge and the South Diversion Channel. Below is a summary of basins and peak flows. Hydrologic calculations are included in Appendix B.

Table 2 - Basin Area and Simplified Peak Flow Method Peak Discharges

Basin

Designation Station Area (acres)

2-Year flow

(cfs)

10-Year flow

(cfs)

100-Year flow (cfs)

B-47 47+00 Rt 0.20 0.16 0.38 0.67

B-48 48+05 Rt 1.06 0.84 2.04 3.58

B-49 47+57 Lt 1.10 2.06 3.47 5.19

B-54 53+87 Rt 1.94 1.53 3.74 6.54

B-65 64+72 Rt 3.10 2.78 6.34 10.87

B-66 65+22 Lt 2.21 2.38 4.98 8.25

B-79 78+51 Lt 0.59 0.59 1.27 2.14

B-81 81+22 Lt 1.10 1.11 2.39 4.01

B-85 84+79 Rt 0.46 0.56 1.11 1.79

B-88 87+24 Rt 4.86 4.18 9.74 16.81

B-89 86+93 Lt 0.16 0.31 0.52 0.77

B-91 89+37 Lt 0.11 0.21 0.35 0.53

B-92L 91+36 Lt 0.08 0.14 0.24 0.36

B-92R 88+00 Rt 0.25 0.38 0.69 0.83

B-93L 92+45 Lt 0.17 0.31 0.53 0.79

B-93R 92+23 Rt 0.22 0.32 0.58 0.71

B-95 95+28 Lt 0.05 0.09 0.16 0.24

B-96L 95+95 Lt 0.16 0.29 0.49 0.74

B-96R 92+82 Rt 0.21 0.30 0.56 0.68

B-98 98+72 Lt 0.05 0.10 0.17 0.26

B-99L 99+25 Lt 0.16 0.30 0.50 0.75

B-99R 99+15 Rt 0.20 0.28 0.52 0.63

B-102 101+97 Lt 0.06 0.10 0.17 0.26

B-103L 102+59 Lt 0.16 0.30 0.51 0.76

B-103R 102+53 Rt 0.20 0.29 0.53 0.64

B-105 105+24 Lt 0.06 0.10 0.18 0.26

B-106L 105+90 Lt 0.15 0.28 0.47 0.71

Street Southwest Corridor 6 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report

Basin

Designation Station Area (acres)

2-Year flow

(cfs)

10-Year flow

(cfs)

100-Year flow (cfs)

B-106R 105+84 Rt 0.20 0.29 0.54 0.65

B-108 108+40 Lt 0.07 0.12 0.21 0.31

B-109L 109+22 Lt 0.15 0.29 0.48 0.72

B-109R 109+21 Rt 0.20 0.30 0.54 0.66

B-112 111+80 Lt 0.07 0.12 0.21 0.32

B-113L 112+66 Lt 0.14 0.27 0.45 0.68

B-113R 112+66 Rt 0.19 0.28 0.52 0.63

B-115 114+98 Lt 0.07 0.12 0.21 0.31

B-116L 115+87 Lt 0.10 0.19 0.31 0.47

B-116R 115+79 Rt 0.12 0.18 0.33 0.39

B-118R 117+85 Rt 0.55 0.80 1.47 1.77

B-118L 117+52 Lt 0.11 0.20 0.34 0.51

B-119 119+24 Lt 0.40 0.74 1.26 1.88

2.2.2 Existing Studies

A detailed study for the Southeast Valley and Mesa del Sol Watershed in the

Albuquerque area was completed by Wilson & Company for Albuquerque Metropolitan

Arroyo Flood Control Authority (AMAFCA) in June 2012 “Southeast Valley Drainage and

Stormwater Quality Management Plan” to provide drainage and water quality alternatives for future development. Several jurisdictions have interest in the area including AMAFCA, Bernalillo County, New Mexico Department of Transportation

(NMDOT), City of Albuquerque (COA), Mesa del Sol, Middle Rio Grande Conservancy

District (MRGCD) and Pueblo of Isleta and private stakeholders. The project is located in one of the four watersheds included in the study, Far Southeast Valley Watershed. The basin map produced for the study is included in Appendix B. 100-year peak flows were reported for existing and future conditions. Peak flows were calculated using the Arid-lands Hydrologic Model 1997 (AHYMO_97). Table 3 summarizes the existing conditions peak discharges to existing drainage structures within the project.

Table 3 – Master Plan Peak Discharges

Basin ID Station Area

(acres)

100-Year flow (cfs)

Desert Road/

Basin 1 86+57 937 1,120

2.2.3 FEMA

The project is located near an effective floodplain and is identified on Flood Insurance

Rate Map (FIRM) panels 0531H and 0343H Bernalillo County, New Mexico and

Incorporated Areas Revised August 16, 2012.

Street Southwest Corridor 7 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report

At the south rural section of the project the floodplain is located west of 2 nd

Street adjacent to the project. The proposed bike trail at the south end of the project in

Segment 1 may be located within the limits of the floodplain.

At the north end of the project a pedestrian bridge is proposed over the South Diversion

Channel which has a defined floodplain. The proposed bridge will span the concrete channel and no work is proposed in the channel and will not impact the floodplain limits.

The MDP floodplain map, Figure 3-5 and a portion of the effective FEMA FIRM panels are included in Appendix C.

3. DESIGN DISCUSSION

3.1. Design Criteria

The design criteria for the project follows procedures outlined in the “City of

Albuquerque’s Development Process Manual” (DPM) Chapter 22 unless otherwise noted. The criteria listed below in the CFLHD Criteria will be used in place of the

Bernalillo County Criteria where noted.

Table 4 – Roadway Hydraulic Design Storm Values

Roadway Hydraulic Design Storm Values

Bernalillo County Criteria CFLHD Criteria

Street Hydraulics

Minor 10-year not to exceed depth of 0.5 feet in any collector or arterial with 1 lane free of standing or flowing water in each traffic direction

Major 100-year not to exceed 0.2 feet above curb height and shall be contained within the street right-of-way

Manning’s roughness coefficients

Streets 0.017

RCP 0.013

CMP 0.025

Arroyo channels 0.030

Medium weight dumped riprap 0.045

Pipes Design as flowing full

Minimum Pipe Size ▪Connector pipe : 18”

▪Areas of high sediment : 36”

Minimum Pipe Slope 0.10%

Minimum Pipe Velocity 3 fps for 10-year design flow

Closed Conduits Angle of

Confluence Between Main

Line and Lateral

▪Not to exceed 45°

▪If peak flow in proposed lateral exceeds 10% of mainline peak flow should not exceed 30°

Manhole Spacing ▪450 feet

▪300 feet for pipe diameter 30” or less

Inlets Type A, B or C (curb inlets)

Culvert Design 100-year

Segment 1, Low

Standard, 25-year

Segment 2, High

Street Southwest Corridor 8 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report

Roadway Hydraulic Design Storm Values

Bernalillo County Criteria CFLHD Criteria

Standard, 50-year

HW/D

New culvert: WSEL ≤ bottom of aggregate base layer

Exiting culvert: WSEL ≤ shoulder hinge point

Diameter ≤ 48” 1.5

Diameter > 48” 1.2

3.2. Existing Structures

nd

Street has only one existing drainage structure and two irrigation structures that intersect the alignment. The existing drainage structure is located at Desert Road and is a 60 inch by 48 inch corrugated metal pipe (CMP). The Rail Runner timber 5 span bridge is just upstream of this crossing. The Barr Main Canal runs parallel to 2 nd

Street south of

Desert Road and crosses north of the Refuge at the Barr Spur Drain.

The existing culvert at Desert Road restricts runoff and causes flooding in the northeast corner of the 2 nd

Street and Desert Road intersection. A poorly defined channel downstream of the existing culvert restricts flow. The channel drains on the west side of nd street south of Desert Road and then intersects the Barr Spur Drain where it overtops Barr Road and overflows into the irrigation canal. The two irrigation structures are both siphons. Table 5 is a list of existing structures.

Table 5 – Existing Culvert Summary

Basin

ID

Station

Existing

Feature

Upstream

Invert (ft)

Downstream invert (ft)

Length

(ft)

1 86+57 60” X 48”

CMP

4940.17 4939.78 77

N/A 65+36 36” CSP 4926.11 4924.90 48

N/A 30+08 24” RCP 4914.77 4913.70 43

3.3. Hydraulic Analysis

The following is a summary of the hydraulic analysis for the design of the various roadway hydraulic structures within the limits of the project. Hydraulic calculations are included in Appendix D. Figure 4-3 Alternative 1 Pond Option A, AMAFCA, June 2012 is also included to show proposed storm improvements for the Far Southeast Valley

Watershed. Figure 6-1, Structure Inventory Map, from the MDP is also included in

Appendix D.

3.3.1. Roadway Drainage

The addition of curb and gutter will be evaluated to determine whether a storm system will be a viable solution and can be drained given the flat terrain.

Street Southwest Corridor 9 Central Federal Lands Highway Division

3.3.2. Culvert Design

Analysis of the existing culvert crossing at Desert Road will be reviewed to determine existing capacities, whether it meets criteria and evaluate the alternatives presented in the SMP. The drainage crossing at Desert Road as well as the irrigation crossings will be evaluated to determine if culvert extensions or replacements will be needed due to the changes in the proposed roadway section and addition of trail.

4. RECOMMENDED DESIGN

4.1. Roadway Drainage

Following the 70% review changes were requested through the urban section from the

County and through public meetings. Previously the urban section had curb and gutter only on the west side of 2 nd

Street. Southbound right turn lanes were also removed after the preliminary design. Based upon 70% plan review curb and gutter was added on the east side of 2 nd

Street and right turn lanes were added back into the design in the south bound lanes. The County also requested additional inlets at every intersection instead of using cross pans.

Curb and gutter on the west side of 2

Street from Cam Siete SW to the school entrance will be captured by inlets (COA Type A). Two storm lines will be required to drain the west curb and gutter; West Storm Line and East Storm Line. The East Storm Line will drain the west curb line inlets from Shirk Lane (Station 119+00) to Cam Seis SW (Station

99+00) in a mainline between the east edge of pavement and proposed trail centered in the 8 foot buffer and will outfall into the drainage swale on the east between the proposed trail and the railroad just north of the Desert Road culvert.

The east side of 2

Street now is collected by curb and gutter and drains to curb cuts with a rundown to a grate inlet (FLH Type 7) located in the 8 foot buffer. The buffer has side slope of 6:1 and 10:1 and 6 inches of depth. There are two low points in the 8 foot buffer at Station 92+45 and 118+75. The 8 foot buffer will also serve as a landscaping area. If the capacity of the swale is exceeded it will overtop the trail and drain to the existing vegetated swale between the trail and railroad. The swale between Stations

88+00 and 92+21 maximum capacity at 0.24% is 1.9 cfs. The swale between Stations

92+25 to 117+85 at 0.45% is 2.6 cfs. To design the storm system for the 10 year storm event with the additional flows from the east pavement the downstream segments were upsized to 24 inch equivalent pipes (27 inch by 21 inch) with grading to accommodate the lowered invert to drain to the Desert Road crossing. If a larger storm event occurs and the system surcharges flow will drain over the trail and to the

Street Southwest Corridor 10 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report vegetated swale between the trail and railroad. This swale will be graded to drain toward the proposed culvert at Desert Road.

The West Storm Line will drain the west curb line from the roadway low point at Station

92+45, and will outfall via connection to the box culvert into the downstream channel of the Desert Road concrete box culvert.

The storm line will be constructed with pipe recommended by the County as best suited for the site conditions. Due to limited cover on the south end of the urban section and minimal grade change the minimum pipe size will be 18 inch equivalent laterals and mainline pipes. The County prefers to use Ultra Flow® Storm Sewer Pipe galvanized, aluminized steel or equivalent. Minimum pipe size is 18 inch. 18 inch equivalent (20 inch wide by 16 inch tall) will be used for mainline and lateral pipes and up to 24 inch equivalent (27 inch wide by 21 inch tall) for a portion of the mainline. Information on

Ultra Flow® is included in Appendix D. The project is located in the valley and therefore has site constraints that limit the capacity of the storm system. The County has agreed to design the system for a smaller storm event than required by criteria. The system will surcharge in the 100-year event. Design calculations are included in Appendix D.

Table 6 –Storm Line Pipe Analysis, 10-year

Pipe ID Pipe Size

(inches)

Q10

(cfs)

Capacity

(cfs)

Slope

(ft/ft) Velocity

(fps)

Flow

Depth

(ft)

East Line

P119L 20x16 1.14 7.07 0.003 2.94 0.37

P119 20x16 1.14 7.49 0.004 3.05 0.36

P118 20x16 2.61 8.17 0.004 4.13 0.52

P116L 20x16 0.29 7.07 0.003 *1.94 0.19

P116 20x16 3.23 9.13 0.005 4.75 0.55

P113L 20x16 0.38 7.07 0.003 *2.11 0.21

P113 20x16 4.14 9.13 0.005 5.09 0.71

P109L 20x16 0.45 7.07 0.003 *2.21 0.23

P109 20x16 5.18 9.13 0.005 5.39 0.72

P106L 20x16 0.42 7.07 0.003 *2.17 0.22

P106 20x16 6.16 9.13 0.005 5.63 0.80

P103L 20x16 0.46 7.07 0.003 *2.24 0.23

P102 20x16 7.21 12.91 0.010 7.59 0.71

P99L 20x16 0.41 7.07 0.003 *2.15 0.22

P99 20x16 8.21 12.91 0.010 7.85 0.77

P96L 20x16 0.41 7.07 0.003 *0.23 1.33

P96 20x16 9.23 7.07 0.003 5.29 1.33

P92 27x21 10.63 13.75 0.003 3.44 1.75

P89 27x21 10.63 13.75 0.003 3.44 1.75

P88 27x21 10.63 13.75 0.003 4.95 1.15

West Line

P93 20x16 0.53 7.07 0.003 *2.33 0.25

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Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report

Pipe ID Pipe Size

(inches)

Q10

(cfs)

Capacity

(cfs)

Slope

(ft/ft) Velocity

(fps)

Flow

Depth

(ft)

P90 20x16 0.88 7.07 0.003 *2.72 0.32

P87 20x16 0.88 7.07 0.003 *2.72 0.32

*indicates design exception

Historically the runoff from the centerline of 2

Street to the west right of way (ROW) sheet flows off the roadway and through the residential area to the west of 2 nd

Street toward the Barr Main Canal. This area has known flooding concerns, however there were no drainage improvements proposed in the SMP for this area. The addition of inlets and curb and gutter will reduce some of the drainage into this area. This change will add 4.0 cfs and 6.0 cfs for the 10-year and 100-year design storm to the culvert located at Desert Road. Runoff will still drain toward the Barr Main Canal with a shorter travel time. The west pavement section is a 1 foot gutter, 10 foot turn lane and 11 foot traveled way. For the minor event flows are not to exceed 0.5 feet of depth and leave 1 lane free of standing water in each traffic direction. The typical section allows for up to

11 feet of spread in the minor event and up to 22 feet in the major event for the southbound lane. The east pavement section is 11 foot traveled way, 3 foot shoulder and 1 foot gutter. The northbound section allows for 4 feet of spread in the minor and

15 feet for major event with maximum depth of 0.5 feet. Due to the minimal longitudinal slopes, the minor storm spread criteria will be exceeded in some locations by approximately 1 foot, but will still leave a 10 foot travel lane open. Additional curb cuts were added to alleviate the spread and allow runoff to reach the landscape area for water quality treatment.

An existing swale is located between the proposed trail and railroad but currently drains to the roadway low point near Clark Road SW (Station 92+00) and in some events, runoff encroaches onto 2 nd

Street. Runoff between the centerline of 2 nd

Street and the railroad centerline currently drains to this swale. The swale will be graded to eliminate the low point in the swale so that it will continue to drain south toward the Desert Road culvert.

Design exceptions for the storm system will be required and have been accepted by the

County. These exceptions include: 10-year minimum pipe velocity of 3 feet per second

(fps), east curb line minor storm spread criteria will be exceeded at some locations and the storm design will not meet the 100-year storm event.

Table 7 –Inlet Analysis

Basin ID

INLET

ID

Station

Structure

Type

10-Year

Flow

(cfs)

Spread

(feet)

(allowable)

Depth

(feet)

(allowable)

100-Year

Flow

(cfs)

Spread

(feet)

(allowable)

Depth

(feet)

(allowable)

B-119 IN119 119+17

Type A

Inlet 1.26

10.9

(11)

0.3

(0.7) 1.88

12.8

(22)

0.4

(0.7)

Street Southwest Corridor 12 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report

Basin ID

INLET

ID

Station

Structure

Type

10-Year

Flow

(cfs)

Spread

(feet)

(allowable)

Depth

(feet)

(allowable)

100-Year

Flow

(cfs)

Spread

(feet)

(allowable)

Depth

(feet)

(allowable)

B-118R IN118 118+75

Type 7

Inlet 1.47

5.4

(8)

0.2

(0.5) 1.77

6.1

(8)

0.2

(0.5)

S-123R Curb cut 122+55 Curb cut 0.25 *5.1

(4)

0.1

(0.7) 0.38

6.2

(15)

0.2

(0.7)

S-120R Curb cut 120+55 Curb cut 0.25 *5.1

(4)

0.1

(0.7) 0.38

6.2

(15)

0.2

(0.7)

S-119R Curb cut

118+82 Curb cut 0.20 3.6

(4)

0.1

(0.7) 0.31

4.7

(15)

0.2

(0.7)

S-118R Curb cut 118+68 Curb Cut 0.09 1.4

(4)

0.1

(0.7) 0.14

2.4

(15)

0.2

(0.7)

B-116R IN116R 115+81

Type 7

Inlet 0.33

4.2

(8)

0.1

(0.5) 0.39

4.5

(8)

0.2

(0.5)

B-116L IN116L 115+83

Type A

Inlet 0.31

5.4

(11)

0.2

(0.7) 0.47

6.7

(22)

0.2

(0.7)

S-116R Curb cut 115+83 Curb Cut 0.25 3.9

(4)

0.2

(0.7) 0.38

5.0

(15)

0.2

(0.7)

B-113R IN113R 112+58

Type 7

Inlet 0.52

4.9

(8)

0.2

(0.5) 0.63

5.4

(8)

0.2

(0.5)

B-113L IN113L 112+60

Type A

Inlet 0.45

5.9

(11)

0.2

(0.7) 0.68

7.2

(22)

0.2

(0.7)

S-113R Curb cut 112+60 Curb Cut 0.38 *4.7

(4)

0.2

(0.7) 0.56

5.8

(15)

0.2

(0.7)

B-109R IN109R 109+23

Type 7

Inlet 0.54

6.1

(8)

0.2

(0.5) 0.66

6.7

(8)

0.2

(0.5)

B-109L IN109L 109+24

Type A

Inlet 0.48

6.4

(11)

0.2

(0.5) 0.72

7.8

(22)

0.3

(0.7)

S-109R Curb cut 109+30 Curb cut 0.38 *5.0

(4)

0.2

(0.7) 0.56

6.1

(15)

0.2

(0.7)

B-106R IN106R 105+87

Type 7

Inlet 0.54

5.0

(8)

0.2

(0.5) 0.65

5.5

(8)

0.2

(0.5)

B106L IN106L 105+88

Type A

Inlet 0.47

5.7

(11)

0.2

(0.5) 0.71

7.0

(22)

0.2

(0.7)

S-106R Curb cut 105+94 Curb cut 0.38 *4.9

(4)

0.2

(0.7) 0.56

5.9

(15)

0.2

(0.7)

B-103R IN103R 102+55

Type 7

Inlet 0.53

5.7

(8)

0.2

(0.5) 0.64

6.3

(8)

0.2

(0.5)

B103L IN103L 102+57

Type A

Inlet 0.51

6.0

(11)

0.2

(0.5) 0.76

7.3

(22)

0.3

(0.7)

S-103R Curb cut 102+63 Curb cut 0.38 *4.9

(4)

0.2

(0.7) 0.56

5.9

(15)

0.2

(0.7)

B-99R IN99R 99+18

Type 7

Inlet 0.52

4.8

(8)

0.2

(0.5) 0.63

5.8

(8)

0.2

(0.5)

B-99L IN99L 99+19

Type A

Inlet 0.50

4.6

(11)

0.2

(0.5) 0.75

5.7

(22)

0.2

(0.7)

S-99R Curb cut 99+24 Curb cut 0.38 3.9

(4)

0.2

(0.7) 0.56

4.9

(15)

0.2

(0.7)

B-96R IN96 95+84 Type 7 0.56 4.7 0.2 0.68 5.2 0.2

Street Southwest Corridor 13 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report

Basin ID

INLET

ID

Station

Structure

Type

10-Year

Flow

(cfs)

Spread

(feet)

(allowable)

Depth

(feet)

(allowable)

100-Year

Flow

(cfs)

Spread

(feet)

(allowable)

Depth

(feet)

(allowable)

Inlet (8) (0.5) (8) (0.5)

B-96L IN96L 95+86

Type A

Inlet 0.49

4.3

(11)

0.2

(0.7) 0.74

5.4

(22)

0.2

(0.7)

S-96R Curb cut 95+91 Curb cut 0.38 3.9

(4)

0.2

(0.7) 0.56

4.9

(15)

0.2

(0.7)

B-93L IN93 94+45

Type A

Inlet 0.53

0.5

(12)

0.06

(0.7) 0.79

0.7

(21)

0.08

(0.7)

S-93R Curb cut 92+29 Curb cut

0.41 *4.9

(4)

0.2

(0.7) 0.61

6.0

(15)

0.2

(0.7)

B-92R, B-93R

IN92 92+23

Type 7

Inlet 1.27

5.2

(8)

0.2

(0.5) 1.54

6.0

(8)

0.2

(0.5)

B-91 IN91 90+77

Type A

Inlet 0.35

0.35

(11)

0.04

(0.5) 0.53

0.49

(22)

0.06

(0.7)

S-92R Curb cut 92+16 Curb cut/IN92 0.25

*4.7

(4)

0.2

(0.7) 0.38

5.8

(15)

0.2

(0.7)

S-90R Curb cut 90+00 Curb cut 0.25 3.6

(4)

0.2

(0.7) 0.38

4.7

(15)

0.2

(0.7)

*indicates design exception

4.2. Culverts

Culvert analysis is performed with the Federal Highway Administration’s HY-8. The existing culvert at Desert Road was surveyed as a 60 inch by 48 inch CMP, documented as a 66 inch by 48 inch in the SMP culvert inventory and was analyzed in HY-8 as a 60 inch by 46 inch CMP as a standard size. This area has documented flooding and the culvert is significantly undersized for the existing 100-year peak discharge of 1,120 cubic feet per second (cfs) developed in the SMP. The finished grade at the roadway centerline is 4947.2. At this discharge the roadway is overtopped. To pass this flow 4-8 foot by 4 foot reinforced concrete box culverts (CBC) with channel improvements would be required to meet current design criteria.

The SMP proposed alternatives that reduces the 100-year peak flow at Desert Road to

280 cfs by adding infrastructure upstream, leaving the existing 60 inch by 48 inch CMP and downstream channel improvements to convey flow to the Barr Main Spur.

The dimensions of the existing downstream channel vary, but from survey the dimensions are 2.6 foot bottom, 4 foot depth with 2:1 and 2.5:1 side slopes. An analysis using FlowMaster shows this geometry will convey 265 cfs at 0.5%. To convey the 454 cfs that is conveyed through the CBC a trapezoidal channel with, 3:1 side slopes, 10 foot bottom and 4 foot depth at 0.5% would be needed, this does not include freeboard. To convey the full 1,120 cfs a 20 foot bottom channel, 3:1 side slopes and 5 foot depth would be required.

Street Southwest Corridor 14 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report

The intersection at Desert Road will be realigned to a T-intersection. This will provide additional area at the CBC entrance as well as the opportunity to install the CBC south of the existing culvert. This will allow the existing culvert to remain online during construction of the CBC.

A downstream channel will be designed and constructed by MRGCD and AMAFCA and will not be constructed as part of the 2 nd

Street Southwest roadway improvements. This channel will be improved beginning at Barr Road and drain toward the Barr Main Spur and to the interior of the Refuge in the Barr Interior Drain as shown on Figure 35

Drainage Map in Appendix B.

The proposed CBC will include headwall, wingwalls, cut off wall, concrete apron at the inlet and outlet and riprap protection upstream and downstream. The channel downstream of the CBC and upstream of the proposed AMAFCA channel work will require improvements to convey the flows from the proposed CBC. This work will require additional ROW and easements to construct and maintain. The site constraints of the project do not allow for a proposed CBC that can convey the 100 year peak flow.

Coordination with Bernalillo County and AMAFCA have determined that this may be an interim condition until funds are available to extend the proposed improvements by

AMAFCA. Existing conditions will be improved to the maximum extent possible by the project. The reduced flow as proposed in the SMP can be conveyed by the proposed

CBC meeting current design criteria. The existing 100 year peak storm will overtop the road. Additional protection will be provided to protect 2 nd

Street embankment. The downstream channel will be improved to convey the flows that can be conveyed by the

CBC. A design exception will be required for current design standards for cross culverts for the proposed CBC. This direction was agreed upon by FHWA, Bernalillo County and

HDR.

The alignment of the proposed CBC initially was placed in line with the upstream railroad bridge. Following coordination meetings regarding the CBC and at direction of

Bernalillo County the CBC was moved south and skewed to outlet further downstream to accommodate right of way on the west. This changes the existing flow pattern and introduces additional bends in the channel. Therefore a basic 1D HECRAS model was developed with what information was available for the project. Existing surfaces from

LIDAR and proposed project surfaces were used. The existing LIDAR surface was insufficient upstream of our project for the railroad channel. The channel surface showed a long stretch with no slope then dropped 7 feet immediately upstream of the rail road bridge, which is not accurate. Therefore, the grade along the channel east of the railroad was adjusted from the bridge and upstream to show a gradual slope toward the railroad bridge without a drop at the bridge. There was not detailed information on the existing railroad bridge available so assumptions on the deck thickness, piers, and opening were based on site photos. The top of rail had been surveyed. A channel section downstream of the bridge was applied for the upstream cross section. A typical

Street Southwest Corridor 15 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report section for the ditch along the east side of the railroad was cut and applied to the channel. Additional information would be needed to accurately model but time and scope did not allow. This model did provide a reasonable assessment of the upstream and downstream channels and how it affects the hydraulics at the existing railroad bridge and proposed CBC, the velocity upstream and downstream of the bridge and through the proposed CBC. An existing and proposed model were developed and analyzed for three different flows: 280 cfs for future improvements, full flow capacity of

406 cfs and the existing 100-year flows of 1,120 cfs.

A deflection will be provided at the downstream end of the CBC to align the outlet of the CBC with the downstream channel. Table 8 summarizes the existing and proposed scenarios for Desert Road cross culvert based on HY8 analysis. This analysis does not consider the change in alignment. The design report is included in Appendix D.

Table 8 – Culvert Analysis

Event Structure Q100

(cfs)

HW HW/D

Existing 60” X 48”

CMP

**1,120 4969.57 6.4

CBC

4- 8’X4’

RCB

**1,120 4946.13 1.4

CMP with SMP

Improvements

60” X 46”

CMP

*280 4944.44 1.0

Proposed CBC 10’x4’

RCBC

*280

**1,120

4944.42

4948.75

1.2

2.3

*reduced flow with upstream Master Plan Improvements

** Existing flow

Table 9 summarizes flows and water surface elevations from the HEC-RAS model at river station 405.1918 for existing conditions and 385.3 for proposed conditions. Output tables and geometric layout of river stations are included in Appendix D.

Table 9 – HEC-RAS Summary

Model

Design

Flow

(cfs)

WSE

Existing

Conditions

149 4946.97

280 4947.79

1,120 4950.23

Proposed

Conditions

280 4944.63

406 4946.95

1,120 4948.98

Street Southwest Corridor 16 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report

It is also documented in the SMP that downstream property owned by the Reservation and the Bureau of Indian Affairs have consistently opposed additional stormwater entering the Pueblo located south of I25.

Outlet protection was evaluated using FHWA Hydraulic Toolbox (v4.2). Full flow of 406 cfs before roadway overtopping occurs was used for the analysis. Riprap protection requires Class 2 (d50 9.5”) rock with apron dimensions of length of 40 feet, 3 feet thick and 57 feet wide at the end of the apron. Class 3 rock will be specified on the plans for additional protection from scour from overtopping flows. The design report is included in Appendix D.

4.3. Ditches

The drainage swale located between the proposed trail and railroad in the urban section will be improved to drain to the proposed CBC at Desert Road. This swale conveys flows between the proposed trail and the centerline of the railroad. The typical section is a trapezoidal ditch with 2 foot bottom, 2.5:1 side slopes off the trail and a varied side slope along the railroad. The longitudinal slope varies but minimum slope is 0.3%. A summary of ditch conveyance, based on minimum slope, is shown in Table 10.

Calculations are included in Appendix D.

Table 10 – Ditch Analysis

Basin ID Q10

(cfs)

Depth

(feet)

Q100

(cfs)

Depth

(feet)

B-88 8.95 1.01 15.65 1.31

4.4. Irrigation

The irrigation structure at Station 30+08 is a 24 inch RCP but has no impacts from the roadway improvements.

The irrigation structure located at Station 65+36 will not be impacted from the roadway improvements.

Irrigation structures should remain and be protected in place.

4.5. Water Quality

The Municipal Separate Storm Sewer System (MS4) maps for Bernalillo County and COA were reviewed and are included in Appendix E. The north end of the project is located within the MS4 required permit areas as shown on Bernalillo County MS4 map. The

Street Southwest Corridor 17 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report

County will be incorporating the remainder of the project into the MS4 area in the near future and wants to include water quality where feasible.

The project is constrained by ROW limitations. Several options for water quality features were evaluated. The 8 foot landscaped buffer will separate the impervious areas. The buffer was previously designed to capture runoff from the east side of 2 nd

Street and would treat runoff as storm water harvesting basins. This can not be accomplished with the addition of curb and gutter with inlets on the east side of 2 nd

Street. However, additional curb cuts were added without inlets to capture runoff prior to reaching curb cuts with rundown directly to inlets.

The vegetated swale between the trail and the railroad will be regraded and will provide better conveyance and treatment for the trail pavement. This swale has a 2 foot bottom with variable side slopes and depth.

A hydrodynamic separator will also be incorporated into the storm line to treat water captured in the inlets. Runoff will be treated at the end of the system identified as

MH88. Information on a hydrodynamic separator and design reports are included in

Appendix E. This feature is based on flow versus volume but also treats total suspended solids (TSS). Although storage is not provided it does capture sediment, free oil and suspended solids. This devise is ideal for locations with limited space.

Water quality volume was calculated from the “Arizona Department of Transportation

Post Construction Best Management Practices Manual for Water Quality” equation

WQv=T(P* A* Cq)/12. Treatment areas were split into west and east for the urban section. The typical landscape area is a v-ditch with 3:1 and 10:1 side slopes with maximum depth of 6 inches. The maximum volume the length of the landscape area would be 0.55 acre-feet.

Table 11 – Water Quality Requirements

Treatment Area Precipitation

Inches

Required WQv

Acre-feet

Provided WQv

Acre-feet

West 0.6

3.14 0

East 6.09 0.55

This area drains toward the Refuge which will have a water quality pond with future improvements. This feature will be designed and constructed as part of a separate project.

5. SUMMARY

The 2 nd

Street improvements will incorporate a storm sewer system to collect flows from the proposed curb and gutter in the urban section. This will provide some alleviation to uncontained drainage in the residential area west of 2 nd

Street. The existing swale will be improved to eliminate an existing low point that spreads onto 2

Street.

Street Southwest Corridor 18 Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Final Drainage

Recommendations Report

To resolve the flooding issues at the culvert crossing at Desert Road additional improvements upstream will be required that may incorporate alternatives proposed in the “Southeast Valley

Drainage and Stormwater Quality Management Plan” but are outside the scope of this project however are being developed by AMAFCA. The proposed CBC will improve the existing conditions but is not able to meet design standards due to site constraints. The alignment of the CBC was directed by Bernalillo County based right of way at the outlet.

Irrigation structures will remain in place and will not be impacted.

Water quality will be incorporated using vegetated swales, landscape area and a hydrodynamic separator.

Street Southwest Corridor 19 Central Federal Lands Highway Division

6. REFERENCES

Arizona Department of Transportation, “ADOT Post-Construction Best Management Practices

Manual for Water Quality”, January 2016.

Bernalillo County, “Post-Construction Storm Water Management in New Development and

Redevelopment”.

Central Federal Lands Highway Division, "Project Development and Design Manual", Chapter 7

Hydrology and Hydraulics, December 2012.

City of Albuquerque, “Albuquerque Development Process Manual”, Chapter 22 Drainage, Flood

Control and Erosion Control, March 1982.

City of Albuquerque, “Standard Specifications For Public Works Construction – Standard Detail

Drawings”, January 2011.

New Mexico Department of Transportation, “Standard Drawings”, October 2015.

Pima County, “Case Studies Low Impact Development Green Infrastructure”, January 2015.

U.S. Department of Agriculture, "NRCS-Web Soil Survey", September 2015.

U.S. Department of Transportation, Federal Highway Administration, "Hydraulic Design of

Highway Culverts", Hydraulic Design Series No. 5, May 2005.

U.S. Department of Transportation, Federal Highway Administration, "Design of Riprap

Revetment", Hydraulic Engineering Circular No. 11, March 1989.

U.S. Department of Transportation, Federal Highway Administration, "Hydraulic Design of

Energy Dissipaters for Culverts and Channels", Hydraulic Engineering Circular No. 14, July 2006.

U.S. Department of Transportation, Federal Highway Administration, "Design of Roadside

Channel with Flexible Linings", Hydraulic Engineering Circular No. 15, September 2005.

U.S. Department of Transportation, Federal Highway Administration, "Stream Stability at

Highway Structures", Hydraulic Engineering Circular No. 20, March 2001.

2nd Street Southwest Corridor Central Federal Lands Highway Division

Valle de Oro National Wildlife Refuge NM FLAP 52000 (1) / Draft Final Drainage

Appendix A – Design Criteria Memo

CFLHD | NM FLAP 52000(1) 2

ND

Street SW Drainage Design Criteria Memo

Memo Date: Wednesday, May 18, 2016

Project: 2 nd

Street Southwest Corridor Improvements and Additions, Valle de Oro National Wildlife Refuge, NM FLAP 52000(1)

To: CFLHD, Bernalillo County

From: Amy Finseth, Liz Staten, PE, HDR

Subject: Drainage Design Criteria Memo

Design Criteria References Drainage design for 2nd Street follows criteria outlined from Central Federal Lands (CFLHD), Bernalillo County, City of Albuquerque (COA) and Albuquerque Metropolitan Arroyo Flood

Control Authority (AMAFCA). The following list includes all drainage references used for the roadway drainage. The drainage criteria for Bernalillo County will be the primary design criteria as they will be maintaining the drainage systems.

• Albuquerque Development Process Manual (DPM), Volume II, Chapter 22 Drainage, Flood Control and Erosion Control, City of Albuquerque, 1982

• Chapter 22 Drainage, Flood Control and Erosion Control, Bernalillo County, May 2013

• Federal Lands Highway Project Development and Design Manual (PDDM), U.S.

Department of Transportation Federal Highway Administration, December 2014

• Southeast Valley Drainage and Stormwater Quality Management Plan, Final – Volume I

– Report, AMAFCA, Wilson & Company Engineers & Architects, June 2012

• The Albuquerque Metropolitan Arroyo Flood Control Authority Resolution No. 1980-15

Drainage Policy, AMAFCA, 1980

Hydrology Hydrology will be developed for local basins using the simplified peak flow method, outlined in

Section 2, Part A of the DPM procedure for 40 acre and smaller basins. All roadway basins are less than 40 acres. Basins include primarily roadway runoff and runoff between the railroad and

2nd Street. These include treatment areas described as C and D. Peak flows are determined based on type of land treatment and peak discharge for the identified zone. The project is located in Zone 2. Equation a-10 below from the DPM is used to calculate peak discharge.

Total QP = QPAAA + QPBAB + QPCAC + QPDAD (equation a-10, COA)

Table 1 – DPM Table A-9 Peak Discharge (cfs/acre)

Zone Treatment

2 A B C D

10-year 0.38 0.95 1.71 3.14

100-year 1.56 2.28 3.14 4.70

Hydrology for the major crossing at Desert Road is taken from the AMAFCA, Southeast Valley

Drainage and Stormwater Quality Management Plan.

Hydraulics

Roadway Drainage

Roadway drainage follows Bernalillo County design criteria. Storm systems are to be designed for the 10- and 100-year design storm. The project is broken into two segments, Segment 1 is a local street and Segment 2 is an urban collector. The following table summarizes the roadway drainage criteria for the project. Due to site limitations, including the project is located in the valley; design exceptions will be allowed and are included below.

Summary of Roadway Drainage Criteria

Design Frequency

Minor 10-year

Major 100-year *Exception – storm system will not convey major storm due to site constraints

Flow Depth

Minor 6 inches

Major

0.2 feet above curb height *Exception – storm system will not convey major storm due to site constraints

Spread

Minor

1 lane free of standing or flowing water in each direction *Exception – may spread into travel way, allow 8 foot lane free of water

Major contained within street ROW *Exception – storm system will not convey major storm due to site constraints

Inlets

Type Type A COA DWG 2201, 2202

Pipes

Material Ultra Flow galvanized, aluminized steel arch pipe

Velocity Minimum 3 fps for 10-year design flow *Exception – may be less than 3 fps due to site constraints

Minimum slope 0.1%

Size Minimum 18 inch or equivalent

End treatments Flared end sections or headwalls

Outlet protection CFLHD Detail C251-50

Clean Out Access 450 feet

Roadway hydraulics will be designed using Bentley Microstation InRoads Storm and Sanitary.

Cross Drainage

Culverts that cross 2nd Street should be designed to convey the 100-year peak storm. Major drainage crossings will be coordinated with on-going studies and sizing recommendations from

AMAFCA. Headwater to depth ration should not exceed 1.5 for culverts 48 inches or less or 1.2 for culverts larger than 48 inches.

Water Quality The project is not located within a municipal separate storm sewer (MS4) area as identified on

Bernalillo County or COA MS4 maps and therefore does not require permanent water quality as part of the roadway improvements. The COA requires that discharges from new development and significant redevelopment are minimized and follow their water quality requirements. COA has a list of priority project categories that have the potential to generate serious post-development stormwater pollution problems. Roadway projects are not on their required list of developments, but will be at the discretion of Bernalillo County.

Appendix B – Hydrology

Valle de Oro National Wildlife Refuge Site Plan ReportMarch 2015 AMAFCA

2203 2204

2228 2229

22412240

2235a

2236a

2237b

2256 2258

2237a

2235b

2236b

2237c

2243B2243A

2203 2204

2228 2229

22412240

2235a

2236a

2237b

2256 2258

2237a

2235b

2236b

2237c

2243B2243A

INTERSTATE

INTERSTATE

60"

48"

42"

66"

66" 66"

54"

60"

54"

66"

66"

4…