CORP OF ENGINEERS PERIODIC INSPECTION REPORT DALLAS FLOODWAY TRINITY RIVER

8/14/2019 CORP OF ENGINEERS PERIODIC INSPECTION REPORT DALLAS FLOODWAY TRINITY RIVER

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U. S. ARMY ENGINEER DISTRICTCORPS OF ENGINEERSFORT WORTH, TEXAS

PERIODIC INSPECTION REPORTDALLAS FLOODWAY

TRINITY RIVERDALLAS, DALLAS COUNTY, TEXAS

REPORT NO. 93-5 DECEMBER 2007

FOR OFFICIAL USE ONLY


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TABLE OF CONTENTS

SECTION NO. TITLE PAGE NO.

I EXECUTIVE SUMMARY

1.1 EXECUTIVE SUMMARY 4

II INSPECTION TEAM AND DATE OF INSPECTION

2.1 INSPECTION TEAM MEMBERS 52.2 DATE OF INSPECTION 6

III SYSTEM BACKGROUND INFORMATION

3.1 PROJECT IDENTIFICATION 63.2 PROJECT AUTHORITY 6

IV PRE-INSPECTION PACKET INFORMATION

4.1 PRE-INSPECTION BROCHURE 8

V INSPECTION FINDINGS AND EVALUATIONS

5.1 GENERAL 85.2 RESULTS OF EXAMINATION FOR EACH FEATURE 85.3 DOCUMENTATION OF SIGNIFICANT GEOTECHNICAL FINDINGS 255.4 DESIGN CRITERIA REVIEW 51

VI LEVEE SAFETY ISSUES AND RECOMMENDATIONS

6.1 LEVEE CREST ELEVATION 556.2 EMBANKMENT CRACKING 556.3 DART BRIDGE 586.4 HAMPTON BRIDGE 586.5 WOODALL RODGERS BRIDGE 586.6 I-35BRIDGE 596.7 EROSION AT OTHER BRIDGE PENETRATIONS 596.8 CONDITION OF ACCESS ROADS 596.9 VEGETATION 606.10 REMOVAL AND REPLACEMENT OF CREEPING SLIDE REPAIRS 616.11 CHANNEL REPAIRS 626.12 SILTATION 636.13 DAMAGE DUE TO UNAUTHORIZED ACCESS 646.14 GATE CLOSURES 64


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SECTION NO. TITLE PAGE NO.

6.15 EMERGENCY ACTION PLAN 64

VII REFERENCES

7.1 REFERENCES 64

VIII ACTIONS TAKEN BY SSD SINCE PERIODIC INSPECTION

8.1 ACTIONS TAKEN 66

APPENDICES

Appendix No. Title

A PROJECT LOCATION MAP

B PRE-INSPECTION BROCHUREC GISMAPSD PHOTOGRAPHSE INSPECTION CHECKLIST (SPREADSHEETS)F DALLAS FLOODWAY MAINTENANCE PROGRAM SUMMARYG FLOOD 2007GEOTECHNICAL TRIP REPORTH LEVEE CREST SURVEYSI CERTIFICATION LETTERJ ACTIONS TAKEN BY SSD SINCE PERIODIC INSPECTIONK AGENCY TECHNICAL REVIEW (ATR)


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I EXECUTIVE SUMMARY

1.1 EXECUTIVE SUMMARY. The Dallas Floodway project protects the CoD, Texas, a majormetropolitan area with a population in excess of 1.2 million people. Located along the ElmFork, West Fork and Trinity Rivers, the Dallas Floodway includes 22.6 miles of levees: 11.7miles on the East levee and 10.9 miles along the West levee. The East levee protects theStemmons Corridor (a major transportation route through the City) and parts of DowntownDallas and the Central Business District from flooding on the Trinity River, while the Westlevee protects a large portion of West Dallas.

These levees were originally constructed by the CoD in the early 1930s in response toextreme flooding along the Trinity River in 1908. Originally constructed with 2.5H:1V side

slopes, a maximum height of 35 feet and a crown width of 6 feet, the levee system wasmodified by USACE in the late 1950s by expanding the levee cross-section, flattening thelevee side slopes and increasing the crest width to 16 feet. Additionally, improvements to theinterior drainage system were also made at that time. Originally authorized to provide floodprotection to a level of SPF + 4 feet, major urban development and land-use changes in thearea since the project was completed in 1958 have reduced that level of protection.Restoration of the authorized level of flood protection will require providing more height onboth the East and West Levees.

In 1999 at the direction of Congress, two additional systems were added to the DallasFloodway: Rochester Levee, which protects residential and commercial interests in EastDallas; and the Central Wastewater Treatment Plant (CWWTP) Levee, which protects critical

infrastructure in South Dallas.

A periodic inspection (PI) of the Dallas Floodway project was performed on 3-5December 2007. This inspection was the 9th PI for the East and West Levee systems, andthe 1st PI for both the Rochester and the CWWTP Levee systems. The inspection wasconducted using procedures utilized during all past PIs of the project (i.e., legacy typeinspections), and did not incorporate the Levee Inspection Checklist distributed in June 2007.When the report documenting the inspection and findings was being written, it wasdetermined that failure to use the new inspection checklist was inappropriate. Therefore,information from the legacy inspection was transferred to the new inspection template.During this transfer, it became apparent that the more subjective ratings from previousinspections of the Floodway would be replaced by ratings determined in accordance with thevery specific language and rating criteria described on the checklist. As a result, significant

deficiencies were documented that resulted in unacceptable ratings for each of the 4systems in the Floodway, and for the Dallas Floodway project overall. Items that generatedunacceptable ratings include:

Insufficient crest height rendering the East and West Levees incapable of successfullyaccommodating the Standard Project Flood without overtopping

Significant encroachments and penetrations that impact the integrity and performanceof the levees, as well as inhibit access for O&M, surveillance, and flood-fightingpurposes


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Damaged gate closures Unstable structures Severe desiccation cracking of the levees Erosion Vegetation Siltation

Channel instability

In addition to numerous unacceptable ratings, it was determined that the DallasFloodway does not meet current USACE design criteria regarding relevant factors of safetyfor embankment stability and seepage gradients.

It is noted that the results of the inspection identify negative impacts during base flood(100-year event) conditions which would jeopardize performance of project features toreliably function as authorized. This is a significant concern that may have a substantialnegative impact on FEMA flood mapping of the areas outside the levees and the residentsand businesses protected by those levees.

According to the Inspection Report Template, the East Levee, West Levee,Rochester Levee, and the CWWPT Levee systems had one or more items rated asunacceptable. Since there is a significant number of deficiencies that would prevent thesystems from performing as intended, the overall rating for the Dallas Floodway project isunacceptable.

II INSPECTION TEAM AND DATE OF INSPECTION

2.1 INSPECTION TEAM MEMBERS. The following were members of the inspection team:

Name Organization

David F. Garcia CoD, Street Services DepartmentMarie Marroquin CoD, Street Services DepartmentDon Lawrence CoD, Street Services DepartmentFrank D. Pechal CoD, Street Services DepartmentMike Johnson CoD, Street Services DepartmentBilly Rios CoD, Street Services DepartmentKelly High CoD, Director, Street Services DepartmentRon Bell CESWD-RBT-W, Water ManagementLes Perrin CESWF-EC-DG, Geotechnical, E&CJos Hernndez (team lead) CESWF-EC-DG, Geotechnical, E&CAnita Branch CESWF-EC-DG, Geotechnical, E&CSteven Chen CESWF-EC-DG, Geotechnical, E&C

Kurt Ley CESWF-EC-DS, Structural, E&CZach Gerich CESWF-EC-DS, Structural, E&CDavid Wilson CESWF-EC-HH, Hydrology & Hydraulics, E&CMark Sissom CESWF-OD-TM, OpsJeff Qunell CESWF-OD-TM, OpsJason Tackett CESWF-PM-ECSO, PPMDJohn Wilson AZ & B

2.2 DATE OF INSPECTION. The inspection was conducted from 3 to 5 December 2007. Theweather was sunny, dry, and cool, with temperatures in the 70s and clear blue skies. The


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elevation of the Trinity River at Baker Pump Station was 383.75 feet NGVD on 2 December2007 (All elevations mentioned in this report are expressed in feet, NGVD). Information,data, and as-built drawings contained in previous inspection reports are referenced, but notrepeated.

This report contains the results of the inspection performed by representatives of theU.S. Army Corps of Engineers (USACE), Fort Worth District (CESWF), and the CoD StreetServices Department (SSD). Authority for conducting PIs and preparing inspection reports iscontained in ER 1110-2-100, Periodic Inspection and Continuing Evaluation of CompletedCivil Works Structures, dated 15 February 1995, and Policy Guidance Letter, PeriodicInspection Procedures for the Levee Safety Program, dated 17 December 2008.

III SYSTEM BACKGROUND INFORMATION

3.1 PROJECT IDENTIFICATION. The Dallas Floodway, Trinity River (West Fork and Elm Fork),Texas, is an urban flood damage reduction project consisting of the following four systems:East Levee, West Levee, Rochester Levee, and Central Wastewater Treatment Plant(CWWTP) Levee. The project is federally authorized and non-federally operated and

maintained.

3.2 PROJECT AUTHORITY. The authority under which the Dallas Floodway Project wasconstructed was the River and Harbor Act approved 2 March 1945 (PL-79-14) (HD403/77/1), and the River and Harbor Act approved 17 May 1980 (PL 81-516) HD 242/81/1.The authority for the Dallas Floodway Extension construction was under Section 301, Riverand Harbor Act 1965, modified by Section 351 WRDA 1996; and Section 356 of WRDA1999. The reimbursement shown in the project cost was authorized by Section 351 WRDA1996 for the useful portions of the Rochester and Central Wastewater Treatment Plant LeveeSystems, which were constructed by the CoD after the floods of 1989, 1990 and 1991.

Section 301 of the River and Harbor Act of 1965 (79 Stat. 1091) was modified toprovide that flood protection works constructed by the non-federal interests along the TrinityRiver for Rochester Park and the Central Wastewater Treatment Plant shall be included as apart of the project and the cost of such works shall be credited against the non-federal shareof project costs.

3.2.1 Estimated Original Cost of Federal Project. The estimated original project cost was$23.9 million.

3.2.2 Construction Completion Date of Original Federal Project. Construction to modifythe original Dallas levees by enlarging the levee cross-section was performed betweenFebruary 1953 and April 1959.

3.2.3 Public Sponsors. The public sponsor is the SSD. The point of contact is David F.

Garcia, P.E., Senior Program Manager, at 214-671-0322.

3.2.4 Location. The project is located in the CoD, Dallas County, Texas, as shown on theProject Location Map provided as Appendix A. The floodway alignment runs along the ElmFork and the West Fork of the Trinity River, Mountain Creek, and the main stem of the TrinityRiver.

The East Levee system extends from river miles 497.9 to 505.5 of the Trinity Riverand 3.8 miles along the Elm Fork. The West Levee system extends from river miles 498.1 to


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505.5 of the Trinity River and 3.6 miles along the West Fork and Mountain Creek. TheRochester Levee system surrounds Rochester Park, and the Central Wastewater TreatmentPlant (CWWTP) Levee system surrounds the plant of the same name.

3.2.5 Potential Consequences. The potential consequences for the Dallas Floodwayproject consisting of populations at risk and the estimated value of the property in theprotected areas are to be obtained from the National Levee Database (NLD), which has notbeen populated at the time this report was prepared.

3.2.6 Investigations Prior to Construction. As-built construction drawings of the DallasFloodway are stored at the SSD Operations Office. The description of the embankment andfoundation materials, design data, basis of design, and stability analyses may be found in theUSACE publication Review of Levee Design, Dallas Floodway, June 1968. Soils data andseepage investigations may be found in the USACE publication Periodic Inspection andContinuing Evaluation of Completed Civil Works Structures, Dallas Floodway, Trinity River,Texas, February 1969, Appendix C, Seepage Investigations of West Levee BetweenStations 134+90 and 196+40, September 1953.

3.2.7 History of Remedial Measures and Major Modifications. The Dallas Floodway

consists of approximately 22.6 miles of levees. The existing levees generally follow thealignment of the original levees, which were constructed between 1928 and 1931. The EastLevee is approximately 11.7 miles long and the West Levee is approximately 10.9 miles long.The original levees had a crown width of 6 feet, an average height of 26 feet, and amaximum height of 37 feet. Side slopes were approximately 1 vertical (V) on 2.5 horizontal(H). The original levees were constructed by dragline with no compaction or moisturecontrol.

The reconstructed levees have a crown width of 16 feet, an average height of 28 feet,and a maximum height of approximately 35 feet. Landside slopes are generally 1V:3H andriverside slopes vary from 1V:3H to 1V:4H. Side slopes of the sumps (excavations in thelandside used as borrow areas) range from 1V:1.5H to 1V:3H, with an average depth of 20feet. The inside slopes of the sumps are generally separated from the landside toe of thelevee by a berm that varies in width from 15 to 40 feet. As mentioned earlier, leveestrengthening construction (from original levees to existing levees) was performed betweenFebruary 1953 and April 1959. The chronology of the levee strengthening and constructionof other features within the project (including contractors) is as follows:

Date Feature Contractor

Jun 1954 Able Pump Station E.E. Const. Co.

Aug 1954 East Levee Strengthening & Sump Excavation John A. Petty Co.

Turtle Creek Pressure Sewer, Part 1 Whittle Const. Co. (WCC)May1955

Turtle Creek Pressure Sewer, Part 2 WCC & McKenzie Const. Co. (MCC)Sep 1955 Pavaho Pump Station List and Clark Const. Co.

West Levee Strengthening & Sump Excavation Cleal T. Watts Co.Nov 1955

Turtle Creek Pressure Sewer, Part 3 WCC & MCC

Dec 1955 Lake Cliff Pressure Sewer MCC

Mar 1956 East Levee Strengthening (I) Cleal T. Watts Co. (CWC)

Sep 1956 Turtle Creek Pressure Sewer, Part 4 WCC & MCC


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Jan 1957 Coombs Creek Diversion Facility WCC

West Levee Strengthening (I) CWCOct 1957

Turtle Creek Pressure Sewer, Part 5 E.H. Reeder Const. Co., Inc.

Dec 1957 East Levee Strengthening (II) CWC

Oct 1958 Hampton Road Pump Station WCC

Apr 1959West Levee Strengthening (II) & ChannelExcavation

Griffin & Dickson Co.

IV PRE-INSPECTION PACKET INFORMATION

4.1 PRE-INSPECTION BROCHURE. Each member of the inspection team was furnished a pre-inspection brochure which contained an agenda, checklists, floodway maps, and actionstaken to previously identified problems. The Pre-Inspection Brochure is provided asAppendix B.

V INSPECTION FINDINGS AND EVALUATIONS

5.1 GENERAL. Most of the items rated as unacceptable and minimally acceptable are shownin the GIS Maps provided as Appendix C (Plates 1 to 9). All photographs referenced inSection 5.2 are provided as Appendix D (Plates D-1 to D-25). Inspection findings aredetailed by system, feature, and rated item in the inspection checklist (spreadsheets)provided as Appendix E. Results of examination for each feature are presented in Section5.2, Results of Examination for Each Feature, and significant findings of the geotechnicalproject components are presented in Section 5.3, Documentation of Significant GeotechnicalFindings.

According to the Inspection Report Template, the East Levee, West Levee,Rochester Levee, and the CWWPT Levee systems had one or more items rated asunacceptable. Since there is a significant number of deficiencies that would prevent thesystems from performing as intended, the overall rating for the Dallas Floodway project isunacceptable.

5.2 RESULTS OF EXAMINATION FOR EACH FEATURE. Results of the visual inspection for thefeatures and components of the systems are discussed below. Findings are for those itemsthat received a minimally acceptable or unacceptable rating.

It is noted that sufficient time was not allocated during the inspection to thoroughlyassess all the various components of project operation, maintenance, and response system;so much of this information was requested after the inspection. The SSD has suppliedwritten responses to demonstrate its capability to manage the project effectively. Theresponses are shown in the Dallas Floodway Maintenance Program Summary provided asAppendix F and these addressed the following items: level of maintenance performed overthe previous five years; required operations and maintenance manuals; emergency suppliesand equipment; flood preparedness and training; and specific preventive maintenance,inspections, communication, and security elements.

As noted in the inspection report template, some components were not inspectedwhile others were not available for review. In some cases a rating was able to be assigned.


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Where there was insufficient data to give a rating, a future inspection should be arranged toassess and validate the projects ability to function as authorized. Special attention shouldbe paid to ensuring permanent functioning of the closure structures and that conduitcondition surveys are conducted periodically.

5.2.1 East Levee Embankments.

The following items were rated as unacceptable (U):

Unwanted vegetation was found at Station 147+70, where a tree is growing on theriverside levee toe and trees were present within 50 feet of the toe near Stations474+, 524+25, and HWY 30 (U). This vegetation should be removed to ascertainlevee integrity.

Encroachments found along the levee consist of 18 bridges, including the DARTBridge. Many had piers on the levee crest, slopes, or within 50 feet of the toe (U).See Plate D-1,Photo EL 3b.

From the DART to the I-35 Bridges (Stations 20+00 to 81+00), there are electric

power towers on the landside lower slopes (U). This was also the case at Stations237+50, 320+ to 364+, and 612+, where electric power towers and poles are presenton the landside levee toe (U). At Station 515+70, the electric power pole was on theriverside levee toe (U). Encroachments inhibit O&M and emergency operations, andmay negatively impact the integrity and performance of the levee.

A construction stockpile was present on the crest of the levee at Station 147+40, andan unauthorized encroachment from the ongoing construction of a jail annex that mayinclude a basement adjacent to the landside levee toe (U). The latter had damagedthe levee section and removed material from the foundation adjacent to the levee toe.See Plate D-1,Photo EL 3c.

Hampton Bridge at Station 292+91 had a 5-foot deep void under the landside bridgeslope paving (U). See Plate D-2,Photo EL 3d. Caving has progressed into the leveesection.

A void was found under the pier support beam on the Highway 183 Bridge at Station546+30 in the riverside of the levee crest (U). See Plate D-2,Photo EL 3e.

The DART Bridge had bridge piers on the levee crest from Stations 13+50 to 22+00(U). See Plate D-3,Photo EL 3f & 6.

Erosion was found around each of the DART Bridge piers on the landside crest of thelevee from Stations 13+50 to 22+00 that had been created by drainage coming from

the bridge. This erosion has significantly reduced the levee crest width and height,creating gullies and exposing the pier foundations (U). See Plate D-3,Photo EL 3f &6.

The crest survey performed in 2003 indicates 47% of the East Levee crest is belowthe SPF elevation (U).

No cracking of the East Levee was observed during this inspection, but a history ofsevere seasonal desiccation cracking has been recorded for this system. Somecracks measured after the PI in September 2008 were up to 4 feet in depth (U).


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Some joint seals were out of the joints between the floodwall panels near the DARTrailroad bridge (U) and brush was growing along parts of the north side of thefloodwall (M). See See Plate D-3, Photo EID 8 and ELF 7. Closures that are in poorcondition or are missing parts may compromise the system in a flood event.

The railroad and paved road stop log gate structures have been compromised byunauthorized removal of their sills (U). See Plate D-4, Photo ELF 3. The placementlocation of the stop log center post beam for the railroad stop log structure was notvisible and appeared to be buried (U). Seepage under the stop logs through therailroad ballast is predicted (U). At Station 13+50 the sand pile for sealing the stoplog was overgrown with weeds and brush. As mentioned earlier, closure structuresthat are in poor condition or are missing parts may compromise the system in a floodevent. Additionally, trial erections have not been accomplished in accordance withthe O&M Manual. This has been a persistent problem due to coordination difficultieswith the railroad (U).

The following items were rated as minimally acceptable (M):

Stations 54+95 and 260+90 had bushes growing at the base of power line towers offthe landside levee toes (M). See Plate D-4, Photo EL 1 and EL 3a.

Johnson grass growth was observed to be widespread over the entire project. Therapid growth of this grass can hinder inspection and make seepage harder to detect(M). A survey of additional areas where unwanted vegetation is within 50 feet of thelevee toe is recommended. Localized bare areas were observed along the levee,commonly near bridge abutments. This makes the embankment soils moresusceptible to cracking and erosion.

The I-35 northbound bridge abutment at Station 81+00 had a void (10'L x 17'W x 4'D)under the broken slope paving of the ramp on the landside of the levee. It also had a

cracked bridge beam on the south abutment ramp (M). Although this feature isoutside the Floodways ROW, the item was rated because it needs to be evaluated inorder to determine its impact on the performance of the Floodway. The situation hasbeen reported to TxDOT bridge authorities.

Station 286+80 and 364+60 had fiber optic line crossings over the levee notstreamlined to the channel (M).

Station 286+95 had a fiber optic line crossing over the levee (M). Station 621+10 hada 48" abandoned water line under the levee (M).

Station 292+90 had a 10-foot diameter concrete debris pile in the channel off of the

riverside levee toe next to the bridge piers (M).

Station 175+70, 380+00, 473+90, and 568+70 had rutting on the levee slopes fromunauthorized recreational ATV use (M).

Slide areas on the riverside slope at Stations 480+20 and 563+40, which had beenrepaired, appeared to be bulging again (M).

Station 54+95 had a repaired landside slide and Stations 320+00, 515+75, 520+00,and 524+25 to 530+75 had repaired riverside slides. At Station 551+50, a repaired


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riverside slope slide had a 1-inch wide crack on the landside crest edge (M). AtStation 175+70, a bench on the riverside mid-slope was observed. These areasshould be repaired.

At Station 25+00 an erosion gully (30L x 4W x 3D) on the landside levee toe ditchwas observed (M). Filter fabric and 12" stone protection had been placed within theerosion gully on the north end of each pier, but this had not been effective as anerosion control measure and gullies have formed on the landside levee slopes.

The TRE Railroad Bridge at Station 473+90 had two erosion gullies (20'L x 2'W x 1'D)on the riverside slope (M). Sylvan Ave. Bridge at Station 225+00 had an erosion gully(12'L x 3'W x 1'D) on the slope under the bridge (M). These erosion deficiencies donot appear to threaten the levee integrity but need to be repaired.

Highway I-30 Bridge at Station 118+30 had multiple large erosion gullies (30'L x 6'Wx 5'D each) under the bridge on the landside slope of the levee (M). Jefferson Bridgeat Station 97+50 had minor erosion on the levee slope (M). These erosiondeficiencies do not appear to threaten the levee integrity but need to be repaired.

The drainage ditch adjacent to the landside levee toe (such as in Station 473+90) andthe sump areas is the typical project condition that would obscure seepage that maydevelop during flood events (M).

Hampton Bridge at Station 292+91 had a 2-inch displacement on the landside bridgeslope paving (M).

Highway 183 Bridge at Station 546+30 had a 6-foot diameter caving/erosion on thelevee slope (M) and the railroad bridge at Station 147+70 had a depression on thelevee slope below the bridge (M).

Continental Ave. Bridge at Station 163+60 had stone protection that was being

displaced down the slope (M). Homeless people appeared to be removing stoneriprap and using it to construct shelters.

5.2.2 East Levee Structures.

5.2.2.1 Belleview Pressure Conduit, Station 59+93.


Shoaling with established vegetation on the right bank is causing the diversion of thechannel into the levee at the Belleview Pressure Conduit. The discharge channelslopes of Belleview Pressure Conduit have been severely eroded (U). Refer to East

Levee Flood Damage Reduction Channels spreadsheet, rated item #2, page 51/53.See Plate D-5, Photos EFD 2a and EFD 2b. This needs to be repaired before theproblem worsens and compromises the levee section and access road.


Damage to the concrete around the perimeter of the outlet was observed. There wasslight rust on the upper bridge girder (M).

5.2.2.2 Able Pump Station, Station 99+45.


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The left gate of the tower is either loose or out of alignment. Either the guide isbroken or the gate was raised too high and came off the guide (U). Most likely theguide has rusted and broke. Project personnel will have to construct a cofferdam inthe outlet trench to effect repairs.

There is a hole (12"W x 24"L) along the curb of the drive above the conduits from thesmall (old) pump house, where water bubbles up at times of high water (U). SeePlate D-6, Photo APS 17.

A concrete drainage chute at the right side of the trash racks for the small pumphouse has failed due to loss of soil underneath the chute (U). See Plate D-6, PhotoEID 7a.


The bearing for the service bridge at the outlet works is cracked and settlement of theabutment at the levee has resulted in bending of the anchor bolts (M).

There was a misaligned joint in the retaining wall at the discharge outlet and a largeconcrete spall on the upstream side of control tower (M).

There has been movement of masonry walls in the large pump house away from theconcrete columns (M).

Trash in the sump pond area next to the trash racks was observed (M).

The chain link fence with razor wire at the top was in good condition. Exterior brickmasonry is cracking near a corner of the pump house (M). Although needing repair,

these are minor structural defects that do not threaten the structural integrity orstability of the structure, and should not impact pumping operations.

5.2.2.3 Woodall Rodgers Pressure Outfall, Station 160+98.


Silt deposits covering 75% of the width of the channel on the right side of thedischarge channel need to be removed (M).

5.2.2.4 Baker Pump Station, Station 235+04.


At the intake for the Baker Pump Station addition, the spalling and continuous verticalcrack on each side of the trash rack, noted in previous inspections, appeared to beunchanged (M).

The lower concrete wall panel right of the trash racks was displaced 1 inch inward,possibly from construction. There was a major fracture in the retaining wall along aset of stairs behind the old pump station (M).


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The fracture had been sealed but either the sealant has shrunk or further separationof the concrete has occurred, causing the sealant to fail. The other stairs have beenshifted about one foot along the upper bearing as a result of being struck by a bobcatthat was clearing trash in the area (M).

There was a broken hand rail at the top of the stairs behind the building (M).

There was bending of the bearing assembly for the service bridge due to settlementof the abutment at the levee. The concrete in the corbel under the beam supports atthe control structure was showing signs of scaling (M).

The service bridge was tilted relative to the bridge abutment and the girder was tightagainst the abutment (M).

The concrete trapezoidal channel next to the trash rack and the earthen ditch in frontof the rack had deposition that should be cleaned out. Trash in the sump pond areanext to the trash racks was observed (M).

The pump station had erosion (4'W x 35'L) on the slope above the discharge chute,erosion (15'W x 35'L) on the left slope, and erosion (50'W x 80'L) on the right side ofthe discharge channel (M). See Plate D-7,Photo EID 7b. There was some corrosionon the four flap gates. Although needing repair, these are minor structural defectsthat do not threaten the structural integrity or stability of the structure, and should notimpact pumping operations.

5.2.2.5 Dallas Branch Pressure Conduit, Station 154+33.


At the control structure, the bottom of two posts for the handrail at the left side of the

tower operating deck had completely rusted out. Due to the height of the tower, thisis a safety issue (U). See Plate D-7, Photo DBP 21.


The replacement of rusted bolts at the base of the stem for the right gate operatorappeared to have caused cracking in the concrete deck. The cracks, unless sealed,will allow future freeze/thaw damage (M).

There was an erosion depression (3L x 2W x1D) on the slope of the service bridgeabutment (M).

Erosion (3L x 1W x 10D) was found on the upstream side of the control structureand another 6-inch erosion depression on the right side of the control structure (M).

There was a 3-foot long crack in the right wing wall of the discharge chute withseepage flowing slowly from the bottom 5 inches of this crack (M).

Deposition was blocking 70% of the discharge channel (on the right side of thechannel) just downstream of the discharge chute. This area should be cleared (M).


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5.2.2.6 Turtle Creek Pressure Conduit, Station 194+13.


The Turtle Creek Pressure Conduit had six trees growing in the upper section of agabion retaining wall on the left side of the channel leading to the intake, and a treegrowing next to the right side of the box culvert at the intake (U). See Plate D-8,Photo EID 2.

The left discharge wing wall was displaced 3 inches with an erosion hole behind it(5'W x 4'L x 3'D). The offset between headwall and wing wall appeared to be gettingworse over time (U). See Plate D-8,Photo EID 6a.


There was corrosion on the lower part of the intake trash rack at the entrance leadingto the conduit (M) and light debris in the intake. The conduit had four locations whereexposed steel reinforcement in the ceiling of conduit is corroding and two locationswhere steel objects are protruding (one from the ceiling and another from the left wall

of the conduit).

There was condensation forming on the ceiling of the conduit approximately at thelocation where the water level in the floor of the conduit deepens. There wasmoderate seepage at some of the joints (M).

The service bridge abutment had settled (M) and erosion (6"W x 6'L x 6"D) was foundon the right side of the control structure (M). See Plate D-9, Photo TCP 5.

A homeless camp was observed under the bridge at the bridge abutment. This isconsidered an encroachment and should be removed (M).

There was erosion on both the right and left slope just above the corners of thedischarge chute (M).

A second wall joint at another location had separated by 1 to 2 inches and movedtowards the channel by 1/4 inch (M). See Plate D-9, Photo EID 6b. There wasdeposition (8'L x 3'W) in the discharge channel.

5.2.2.7 New Hampton Road Pump Station, Station 309+08.


Riprap displaced from the slopes of the discharge channel to the bottom of the

channel had exposed bedding (U) and the riprap stones accumulated at the bottom ofthe channel. There was erosion (30L x 17W) on the right channel slope just past theriprap slope and shallow slides on the downstream right and left slopes. See Plate D-10,Photos EFD 10 and EID 14.

5.2.2.8 Old Hampton Road Pumping Plant, Station 312+05.



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The concrete slabs adjacent to the structure have settled 6 inches on both sides ofthe structure (M). The slab of the service bridge is uptight against the abutment (M).The vertical joint at the corner in the left wing wall at the intake for the pump stationhas a large gap between the concrete sections (M). Refer to rated item #5.

The fiberglass dome supporting the manhole cover over the low flow for the pumpstation had failed (M).

The vertical joint at the corner in the left wing wall at the intake for the pump stationhad a 2-inch separation and the left wall had tilted toward the channel by inch atthe joint (M).

An erosion gully (2'W x 10'L x 18"D) caused from run-off from the parking lot abovethe left intake wing wall was observed (M).

Metal plates at the end of the bridge deck and bridge abutment are butting up againsteach other (M).

The headwall at the outlet was showing a significant bend (M) and corrosion on theflap gate was observed. See Plate D-11, Photo HRP 13. Although needing repair,these are minor structural defects that do not threaten the structural integrity orstability of the structure, and should not impact pumping operations.

5.2.2.9 Six Gravity Sluice East Levee Station 235+04.


Erosion was found on the slope above the sluice discharge head wall and also onboth the right (70L x 20W x 6D) and left (60L x 17W) slopes of the dischargechannel just beyond the wing walls.

5.2.2.10 Elm Fork Sluice East Levee Station 601+32.


The Elm Fork facility was not in service. Exposed steel reinforcement at the bridgesupport on the control structure and an 8-inch erosion depression on the slope side ofthe service bridge abutment was observed (M). Erosion had created a 25-footdiameter pond just upstream of the Elm Fork Sluice discharge channel.

5.2.2.11 Emergency Control Structure.


The service bridge was tight against both the bridge abutment and control structure(M). There was an 8-inch erosion depression on the slope side of the control structureand the service bridge abutment on the levee (M).

5.2.3 West Levee Embankments.



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At Eagle Ford Sluice (Station 479+72), trees were growing on the landside leveeslope (U). See Plate D-11,Photo WL 1. At Stations 350+00, 371+50, 376+50, andnear HWY 30, trees were also growing within 50 feet of the levee toe (U). Thisvegetation should be removed to ascertain levee integrity.

Encroachments found on the levee included 15 bridges. Many had piers on the leveecrest, slopes, or within 50 feet of the toe (U). See Plate D-12,Photo WL 3a.

Walton Walker Bridge at Station 475+65 had its pier support buried in the levee (U).The levee crest was excavated under the Houston Street Bridge and had reduced thecrest width (U).

At Station 18+90, a power line tower was found on the landside levee toe (U). SeePlate D-12,Photo WL 3b.

From the DART to I-35 Bridges (Stations 20+00 to 81+00), electric power towerswere found along the landside levee toe (U). See Plate D-13,Photo WL 3d.

The previous deficiency was also the case at Stations 237+50, 320+ to 364+, and612+ (these had either electric towers or poles and were located on the land sidelevee toe) (U).

At Station 515+70 an electric power pole was found on the riverside levee toe (U).

A series of power line poles on the land side levee slope/toe and cabled pole vehiclebarriers on the land side levee slope was observed upstream of Station 171+40 (U).

More power poles were found on the land side levee toe downstream of Station267+95 (U).

Station 500+00 had a pole on the riverside levee slope (U). Utility encroachmentscrossing the levee included: a gas line crossing at Station 253+70 not streamlined tothe channel (U), a 6-inch jet fuel pipeline crossing at Station 329+70 (U), and an 8-inch petroleum line crossing over the levee streamlined to the channel at Station466+50 (U). See Plate D-13,Photo WL 3c.

Stations 11+90 and 25+40 had unidentified lines crossing the levee (U).

The crest survey in 2003 indicates 42% of the West Levee crest is below the SPFelevation (U). The levee crown was below design elevation at Station 54+14(-1.17feet), 70+00(-0.66 feet), 160+00 to 315+00 (max. of -2.61 feet), 340+00 (-0.33 feet),and 380+00 to 570+00 (max. of -1.21 feet) according to the 2003 survey.

Three-inch deep mower rutting on the riverside slope around the Pump Station Deltaservice bridge was observed. No cracking of the West Levee was observed duringthis inspection, but a history of severe seasonal desiccation cracking has beenrecorded for this levee system. Some cracks that were measured in September of2008 were up to 4 feet in depth (U). Tension cracks along the crest of levees or theface of the slopes fill up with water when it rains and may cause slides to occur.



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Johnson grass growth was observed to be widespread over the entire system. Therapid growth of this grass can hinder inspection and make seepage harder to detect(M). A survey of additional areas where unwanted vegetation is within 50 feet oflevee toes is recommended. Localized bare areas were observed along the levee,especially near bridge abutments. This makes the soil more susceptible to crackingand erosion.

Stations 244+80 and 309+30 had a fiber optic line crossing over the levee notstreamlined to the channel (M). I-35 Bridge northbound at Station 52+50 had fourshopping carts full of removed rock protection most likely being to be used for ahomeless shelter (M). A sewer line repaired at Station 503+50 had increased thelevee section at this location.

Repaired slide areas were observed at Stations 316+00 (2 slides), 317+60, 338+40,350+00, 371+50 to 376+50, and 377+50 (a 420L repaired riverside shallow slide)(M).

Erosion gullies were found at the I-35 Bridge northbound, Station 52+50, on theriverside levee slope (M). A 20-foot long erosion gully was found at Station 134+20

on the riverside levee ramp (M). An erosion gully was found next to a pier at WaltonWalker Bridge, Station 475+65 (M). See Plate D-14,Photo WL 6.

Corinth Street Bridge at Station 5+40 and Union Pacific Railroad Bridge at Station133+20 had depressions on the riverside levee slope protection under the bridges(M).

5.2.4 West Levee Structures.

5.2.4.1 Charlie Pump Station, Station 68+32.


Power poles upstream and downstream of the pump station at the same elevation asthe pump station were observed leaning in the slope direction.

An erosion void (10L x 1.5D) under the concrete stairs on the west side of the pumphouse and a gully running down the slope from this erosion was found. It is unclearhow far back the void goes (U). See See Plate D-15, Photo CPS 5a.


Debris was obstructing 10% of the inlet for the small pump house (M).

Trash was found in the sump area next to the trash racks (M).

The concrete on the bridge support corbel under the bridge girders was scaling at thecontrol structure (M).

Erosion gullies were found on both slopes of the discharge channel. The right gullywas 20L x 5W x 3D and the left was 7L x 2W x 1D (M).

There was erosion on the right toe (5'W x 10'L) of the discharge channel (M). The


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discharge outlet was submerged. Although needing repair, these are minor structuraldefects that do not threaten the structural integrity or stability of the structure, andshould not impact pumping operations.

5.2.4.2 Delta Pump Station, Station 267+95.


A slope slide (60'W x 70'L x5'D) has occurred just upstream and below the pumphouse that should be stabilized (U).


Erosion had washed out soil from under a concrete structure behind the pump house(M). See Plate D-15, Photo DPS 5.

Corrosion on the trash racks and trash was observed in the sump area (M). SeePlate D-16, Photo DPS 21.

A bridge abutment bolt was found bent on the levee end of the bridge (M).

There was erosion (50'W x 80' L x 12'D) on the right discharge channel slope next tothe discharge chute (M). Although needing repair, these are minor structural defectsthat do not threaten the structural integrity or stability of the structure, and should notimpact pumping operations.

5.2.4.3 Lake Cliff Pressure Conduit, Station 75+92.


A 6-inch erosion depression on the slope side of the service bridge abutment was

observed (M).

Three minor erosion gullies (40L x 8W x 8D) were found on the slope above thedischarge chute on the left side of the wing wall (M).

Corrosion on flap gate was noted (M).

5.2.4.4 Coombs Creek Pressure Diversion Facilities, Station 93+57.


The right wing wall had a 3-inch separated joint exposing the rebar (U). See Plate D-

16, Photo WID 6a.


One of the bridges had its plate girder up against the abutment and the rocker armpositioned back further than it should be (M).

The non-mechanical trash racks at the inlet was bent and had corrosion (M). SeePlate D-17, Photo CCP 21.


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Exposed steel reinforcement was found in the ceiling, and cracks were observed onthe floor and the wall of the conduit (M).

A 16-foot long safety handrail on the right discharge wing wall has broken off and wasin the bottom of the discharge channel (M).

Two erosion gullies (6L x 1W x 1D - each) were found above the discharge chute onthe right slope (M). A slope slide (65L x 15W x 1.5D) on the right slope just past theright wing wall and deposition in the discharge channel were observed. The outletwas submerged.

5.2.4.5 Little Coombs Creek Pressure Diversion Facilities, Station 97+29.


The steel brace installed to prevent movement of the wing wall had becomedisconnected from the right wing wall and had failed (U). See Plate D-17, Photo WID6b.


The service bridge abutment had moderate cracking (M).

The bottom of the conduit had a 6" diameter hole, a scour area, and a failed patchover a second scour area (M).

Debris behind the flap gate was preventing it from sealing (M) and corrosion on flapgate was noted on the flap gate (M).

Erosion gully was found on the right channel slope (5'W x 12'L x 2'D) of the discharge

channel (M).

5.2.4.6 Pavaho Pump Station, Station 174+60.


Erosion (20L x 20W x 4D) had exposed the concrete piers supporting the drivewayon the downstream side of the pump station where the trash container is located (U).See Plate D-18,Photo PPS 5. This is above the wing wall on the downstream side ofthe trash rack and should be repaired as soon as possible.


The chain link fencing was leaning on the east side of the building (M).

The left intake wing wall has a 1-inch separation from the intake (M) and there was a5"W x 8"L tear on the right side rail screen of the trash rack.

The bottom of the trash rack was silted in at the small inlet for the left structure withdebris that obstructs 10% of the inlet (M).


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Light debris was found in the sump area (M) and three 36" RCPs appeared to be abandoned at the left side of the sump (M).

The discharge channel had a slope slide on the left bank (35'W x 150'L) and anotherslide (12'W x 20'L) on the right lower slope also (M). Although needing repair, theminor structural defects that do not threaten the structural integrity or stability of the

structure, and should not impact pumping operations.

5.2.4.7 Eagle Ford Sluice West Levee Station 479+72.


Trees were growing around the levee toe drainage ditch (U). This vegetation shouldbe removed. See Plate D-18,Photo WID 1a.

Sediments had filled in and blocked 60% of the inlet (U). See Plate D-14,Photo WID1b.

The sluice had sustained significant structural damage to the walls of the structure(U). This has supposedly been corrected but should be verified.


The control building located on the landside of the levee crest had an erosion gully(6"W x 3'L x 1'D) on the upstream landside corner of the pad that was eroding towardthe building. This erosion had already undermined a corner post of the guardrail (M).These erosion deficiencies do not appear to threaten the levee integrity but need tobe repaired.

Debris behind the left flap gate at the outlet is preventing it from closing tightly (M).

5.2.4.8 Abandoned structures.


According to PI Report #8 (October 2002), there is an abandoned 48-inch sewer linethat runs under the levee at the downstream end of the west levee, and there mightbe another 36-inch interceptor line near Cadiz Street that has been abandoned.Project personnel should verify that these sewer lines were properly plugged andnotify SWF. Debris had obstructed 50% of the inlet at the Ledbetter Sluice (U). SeePlate D-19,Photo WID 1c.

5.2.5 Flood Damage Reduction Channels.


The abandoned old Santa Fe Railroad Bridge catches debris and obstructs flow andshould be removed (U). See Plate D-19,Photo EFD 1.

Shoaling with established vegetation is causing the diversion of the channel into thelevee along Belleview Pressure Conduit at East Levee Station 59+93 (U). Thiscondition, if not corrected, may compromise the levee section, access, and integrity.


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Trees and other vegetative types growing in the flood plain and channel slopes onboth abutments of the Santa Fe Railroad Bridge should be removed (M).

Debris caught in the Continental Bridge piers was observed (M). The Sylvan AveLake Development Park was seen in the flood plain just downstream of Sylvan Ave(observation).

Construction equipment was in the flood plain at East Levee Station 157+50 (or WestLevee Station 141+80) (M).

A concrete debris pile 10 feet in diameter was found in the channel next to HamptonRoad Bridge at Station 292+91 (M).

A 700-foot long area of standing water in the flood plain at East Levee Station 380+00has attracted recreational vehicles (ATVs), leaving rutting (M).

A 100-foot diameter area of standing water in the flood plain at East Levee Station568+70 had rutting caused by ATVs (M).

A sludge lagoon was in the flood plain near East levee Sta. 621+00.

The right side of river bank at Station 161+00 had failed and fallen into the riverchannel (M).

5.2.6 Rochester Levee.


Station 51+00 had a sanitary sewer control valve on the levee crest (U) and a sewercrossing under the levee (U).

A 24-inch diameter, 12-inch deep moist depression was found on the levee crest nearthis crossing (U).

Large trees were observed within 50 feet of the landside levee toe (U). Thisvegetation should be removed.

The mechanically stabilized earth (MSE) retaining wall on the riverside levee slopeapproximately between Stations 114+00 and 120+00 had separation in its concretepanels of up to 2 inches wide at the corner, indicating lateral movement of the wall

(U). See Plate D-20, Photo RL 5a. Project personnel have reportedly beenmonitoring the gap sizes in the wall and have reported no additional movement overthe last 15 years.

The guardrail on top of the MSE wall was leaning towards the riverside approximatelyfrom Stations 114+00 to 120+00. See Plate D-20, Photo RL 5b.

Power poles and their anchorages on the levee crest between Stations 121+55 to130+00 were leaning toward the riverside of the levee (U). See Plate D-21,Photo RL


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3. The power poles encroaching on the levees should be removed off the levee to atleast 50 feet from the toe.

Three active closures were inspected and no records of trial erections have beenverified (U).

The first closure inspected was the "Railroad Street Closure" that was tied into bermson both sides. At the Railroad Street closure, the ladder was bent on one of theswinging gates and the turnbuckle was jammed between the steel attachments, thusnot being able to create a tight closure for the gate (U). See Plate D-21, Photo RFW3a.

The second closure inspected, the "levee closure" structure for the railroad track wastied into berms on both sides. This closure did not have a concrete sill (U). Closurestructures that are in poor condition or are missing parts may compromise the systemin a flood event.

The sheet pile floodwall design needs to be reviewed. Seepage along the side of thesheet pile floodwall is a known weakness on this type of floodwall design. A

geotechnical investigation will be required (U).

The right side of the intake gravity flow structure had a 2-foot deep gully next to thewing wall (exposed/washing out bedding) and the left side had a 18L x 10W areadepression on the gabion slope next to the wing wall (U). See Plate D-22,Photo RID15.


Recent elevation survey records are needed to verify if the current levee elevation isadequate (M). No cracks were found along the levee during the inspection.However, seasonal desiccation cracking is common in this area.

The third closure was the "floodwall stop log closure structure for the railroad tracktied into a flood wall on one side and a berm on the other. The bottom seals on thestop logs of this closure are deformed near the ends due to the stop logs being storedwith a section of the bottom seals resting on concrete stands (M). See Plate D-22,Photo RFW 3b.

When the seals are replaced, it is recommended that the concrete stands be adaptedto hold the stop logs without the rubber seals resting on the concrete by cutting agroove in the concrete for the seals. Minor spalls on the corner of this closurestructure were observed. Light vegetation up to 6 feet high was growing against thewest side of the floodwall at several locations (M).

An area of erosion gullies (60L x 10W x 18D) on the slope was found on the rightside of the pump station inlet at Station 87+00 (M).

A second area of erosion (6L x 2'W x 10"D) behind the right wing wall of the intakewas observed also (M).

Corrosion was noted on the pump station flap gates and walkway platform (M).


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second flap gate was noted as being under water.

Pipe interiors have not been inspected. Additionally, the pump station in the center ofthe facility has not been inspected.

5.2.8 Emergency Action Plan (EAP). The CoD stated that they have a general EAP and anevacuation plan. The SSD has a written system-specific flood response plan and maintainsthat it can effectively respond to emergency situations. SSD should provide a copy of theEAP to SFW (Operations, E&C, and Levee Safety Program Manager) for review. Recentflood activities in 2007 attest to the quick response generated by the Sponsor to protectproject features.

5.3 DOCUMENTATION OF SIGNIFICANT GEOTECHNICAL FINDINGS.

5.3.1 East and West Embankments.

5.3.1.1 Surface Cracks. None noted during the inspection, but no cracking isactually unusual for the project. See Part VI of this report for additional discussion.

5.3.1.2 Sliding and Sloughing of Levee Slopes. Four shallow slides that hadoccurred during the summer of 2007 had been repaired. See trip report provided as


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Appendix G for details. However, these repairs appeared to be creeping. No othersignificant sliding or sloughing of the levee slopes was noted.

PHOTO 1 - 3 December 2007. Slide #286 occurred during the summer of 2007. Although it hadbeen repaired using plastic clays blended with lime, the repair appeared to be creeping.

5.3.1.3 Vertical and Horizontal Alignment of Crest. Significant vertical orhorizontal misalignment of the crest was not observed. However, a survey of the crestindicates that the crests of both the East and West levees are low over significant reaches.See Part VI, Levee Safety Issues and Recommendations for additional discussion.

5.3.1.4 Cracking or Movement at Toe. None noted.

5.3.1.5 Seepage. None noted, but the presence of drainage ditches and sumpslocated along most of the dry side levee toe would make it very difficult to observe seepage

under most cases since these features are generally filled with water.


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PHOTO 2 - 3 December 2007, East Levee. View of the East Levee looking upstream. Water in thesump areas adjacent to the levee, under both normal and flood conditions, would obscure seeps thatcould develop in the dry side toe area.

5.3.1.6 Erosion. Erosion was observed at several locations along the Floodway, primarily inthe vicinity of bridges, adjacent to the channel, and in the vicinity of discharges. See Section5.3.2, Channels (Mainstem Trinity, Inlets and Outlets). Erosion of the levee slopes wasrelatively minor. However, a loss of material at the levee toe adjacent to the outlet for theOld Baker Pump Station is a concern, as was erosion beneath the I-30 and DART Bridges(see Photos 3 and 5a).


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PHOTO 5a - 3 December 2007, I-30 Bridge, EastLevee. Substantial erosion under the I-30 Bridgeat the dry side levee toe would likely have anegative impact on the levee during high waterevents since the interior drainage would exceedthe capacity of the channel visible near the top ofthe photo, resulting in inundation of the levee toe.Interior drainage capacity behind the East Levee isless than required to accommodate a 100-yearevent.

PHOTOS 5b (top) and 5c (bottom) - 3December 2007, DART Bridge, EastLevee. The erosion under the DART Bridgeis a serious levee safety concern. Repairsneed to be made as soon as possible.

5.3.1.7 Condition of Access Roads. In general, the condition of the access roadsthroughout the project was good (see Photos 6a and 6b). Numerous bridge crossings on theEast and West Levees, however, prevent continuous access and restrict the ability tomaintain and repair the levees in the area of the crossings. In several places, the bridgesare at or below the levee crest. In these areas, access has been routed down the levee

slopes to the wet and/or dry side levee toes.


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PHOTO 6a - 3 December 2007, Access Road atLevee Crest, East Levee. The access roads atthe levee crest are graveled to allow access undermost conditions. Note bridge in background thatprevents continuous access along the crest.

PHOTO 6b - 3 December 2007, Access Roadat Wet Side Levee Toe, East Levee. Theaccess road at the toe of the levee had beenrecently graded and was in acceptablecondition. Note rutting near center of photo.

5.3.2 Channels (Mainstem Trinity, Inlets and Outlets).

5.3.2.1 Mainstem Trinity Channel. Inspection of the mainstem river channelindicates a few areas of instability, with some debris and siltation occurring. The mostserious non-compliance with CESWF vegetation policy is generally located along thechannels, where trees are found in abundance (see Photos 7a and 7b). All vegetation,except for short grass cover, on the channel side slopes or is within 50 of the top of the riverbank needs to be removed.

PHOTO 7a - 3 December 2007, TypicalChannel Looking DS from Continental Bridge.The left bank was in generally good condition.However, instability is evident on the right bank.Trees along the channel do not meet vegetationpolicy and need to be removed.

PHOTO 7b - 3 December 2007, Channel atContinental Bridge, Looking US. Debris fromflooding in the summer of 2007 was lodgedagainst the piers of the bridge, partially blockingthe channel. Similar blockages were noted atbridges throughout the Floodway.


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5.3.2.2 Pump Station Sump Areas. Silt had been recently removed from behind theBaker and Hampton Pump Stations.

PHOTO 8a - 3 December 2007, Baker PumpStations, East Levee. The sump area behind

the pump stations had been cleaned of silt anddebris and was in good condition.

PHOTO 8b - 3 December 2007, HamptonPump Stations, East Levee. The sump had

been de-silted in the September-October 2007time frame and was in good condition.

5.3.2.3 Inlet and Outlet Channels. Inspection of the various inlet and outletchannels for the project indicates local areas of instability and some siltation are occurring.

PHOTO 9a - 3 December 2007, Baker PumpStation, East Levee. The side slopes of the inletchannel nearest Old Baker are over-steepened.However, no signs of instability were noted.

PHOTO 9b - 3 December 2007, Old BakerPump Station Outlet Channel, East Levee.The discharge channel was in minimallyacceptable condition, with some back of bank

erosion observed (see Photo 3 for another view).


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PHOTO 10a - 3 December 2007, New HamptonPump Station Outlet, East Levee. Thedischarge channel was in minimally acceptablecondition, with some back of bank erosionassociated with surface drainage into the channel

observed. The slides need to be repaired.

PHOTO 10b - 3 December 2007, Outlet forBelleview Pressure Sewer, East Levee.Erosion at outlet of Belleview Pressure Sewer.Repairs are necessary to protect the access roadalong the wet side the levee toe, visible in the

lower left foreground.

PHOTO 11a - 3 December 2007, Dallas BranchOutfall, East Levee. Some siltation of the outfallchannel is occurring. De-siltation is required torestore capacity.

PHOTO 11b - 4 December 2007, Lake CliffOutlet, West Levee. The channel for this pumpstation is partially silted in. De-siltation isrequired to restore capacity.

5.3.3 Encroachments and Penetrations. Hundreds of encroachments and penetrations ofthe levee were noted during the inspection. Most of these penetrations are not new and

include electrical transmission towers, wooden power poles, fences, bridges andmiscellaneous structures.

5.3.3.1 Dallas County Jail Expansion, East Levee. Located upstream of theCommerce Street Bridge, construction of an expansion to the Dallas County Jail wasongoing. In addition to excavations adjacent to the levee toe, the contractors field office andstaging area were located on the crest of the levee and dry side levee slope. A chain linkfence had been installed along the levee crest to secure the staging area (see Photo 12).


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Discussions with the contractor revealed that during excavation of the basement, thecontractor encountered fill consisting of steel, concrete, iron, and paper. Concrete ticketsfound in the excavated materials indicate that the waste fill has been in place since at least1972.

PHOTO 12 - 3 December 2007, Dallas County Jail Expansion, East Levee. This unauthorizedencroachment is located US of the Commerce Street Bridge and includes a basement immediatelyadjacent to the dry side levee toe.

This expansion worsens the unauthorized encroachment associated with constructionof the original Dallas County Jail (see Figure 1), and further impedes access for O&M. Itrestricts the ability to make repairs due to reduced space at the toe of the levee, and thebasement excavation may contribute to seepage and stability problems.


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Figure 1 - Footprint of the Dallas County Jail Facility with Respect to the East Levee. Thisfacility presents a significant risk to the levees integrity. The large rectangular building south of thebridge is the state jail facility, another unauthorized encroachment that may also impact theperformance of the levee. (Google Earth Photo)

5.3.3.2 Electricity Transmission Towers. Foundations and anchorages fortransmission towers penetrate the levees throughout the Floodway and are considered to beunacceptable with respect to levee safety. These encroachments impact access for O&M,restrict the ability to make repairs due to restricted clearance, and provide pathways for waterthat can contribute to seepage and stability problems. Typical transmission tower

penetrations are shown in Photo 13.


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PHOTO 13 - 3 December 2007, Encroachments, East Levee. View of transmission towers at thedry side toe of the east levee. Foundations for these towers are typically concrete piers, 6 to 8 indiameter.

5.3.3.3 Bridges. Foundations elements for at least 23 bridges penetrate the Eastand West Levees (see Figure 2). Many of these bridges pre-date the levee expansionimplemented when the Dallas Floodway became a USACE flood damage reduction project inthe 1950s. One of the bridges, the Houston Street Bridge, was constructed in 1918 and pre-dates the original levee project constructed by the SSD in the 1920s.

Typical bridge penetrations are shown in Photos 14 through 16. Observations andfindings at bridges that are of particular interest or concern are discussed below.


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Figure 2. At least 23 bridges cross the Dallas Floodway. All of these encroachments have an impact on the penetrations and /or restrictions to access for operations and maintenance, surveillance, and flood fighting. (Google E


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PHOTO 14a - 4 December 2007, I-35 Bridge,West Levee.

PHOTO 14b - 4 December 2007, ContinentalBridge, West Levee.

PHOTO 15a - 4 December 2007, WaltonWalker Bridge, West Levee.

PHOTO 15b - 4 December 2007, WaltonWalker Bridge, West Levee.

PHOTO 16a - 4 December 2007, SylvanAvenue Bridge, East Levee.

PHOTO 16b -4 December 2007, Highway 183Bridge, East Levee.


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5.3.3.3.1DART Bridge. Substantial erosion damage was noted on the levee at theDART Bridge. The erosion is caused by discharge from downspouts that drain the bridgedeck. The condition of the levee in this area of the project is unacceptable, and it will notperform as designed at the SPF level. Performance at the 100-year flood level isquestionable due to the impact of the piers on the seepage paths under and through thelevee. It is noted that this encroachment was approved by USACE more than 20 years ago.

PHOTO 17a - 3 December 2007, DART Bridge,East Levee. This photo illustrates the seriouserosion that is typical at the pier penetrationsalong this section of the levee.

PHOTO 17b - 3 December 2007, DART Bridge,East Levee. Approximately 1,400 feet of leveehas been degraded as a result of the constructionof the DART Bridge.

5.3.3.3.2 I-35 Bridge. Adjacent to the dry side levee toe, the concrete slopeprotection beneath the bridge has failed due to loss of support. The mechanism for the lossof material is unknown, but it is possibly related to drainage from the bridge abutment. Thevoid under the broken slab extends under the adjacent slabs and the east abutments pier

cap, exposing piles used to support the abutment (see Photos 18a and 18b). This itemneeds to be evaluated to determine its impact on the performance of the Floodway.

Of more critical concern for public safety is the condition of the bridges pier caps andabutment, where large, structurally significant cracks were noted. This is not a SSD issueper se, but it is noted for record as a serious public safety concern. Mr. Zach Gerich,CESWFs structural engineer, notified TxDOT on 7 December 2007 as to the condition of thebridge seats.


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PHOTO 18a - 3 December 2007, I-35 Bridge,East Levee. The concrete slope paving underthis bridge has failed and needs to be replaced.

PHOTO 18b - 3 December 2007, I-35 Bridge,East Levee. Piles exposed by the failure of theconcrete slab indicate significant loss of soil.

5.3.3.3.3 Hampton-Inwood Replacement Bridge. Construction of this bridge was

approved by CESWF in February 2006, prior to issuance of Section 408 policy guidance inOctober 2006. This bridge replaces the old Hampton-Inwood Bridge. Pier spacing for thenew bridge is greater than that of the old bridge, resulting in reduced hydraulic conveyanceimpacts (see Photo 19). Additionally, the grade of the new bridge is approximately 5 feethigher than the old bridge, an improvement that allows access for SSD passenger vehicles(see Photos 20 and 21). Although this bridge is considered to be an improvement to theFloodway when compared to the structure it replaced, mitigation measures now need to beincorporated into its design to address impacts of the penetrations on the levee and itsfoundation.

PHOTO 19 - 25 July 2008, Hampton Bridge, East Levee. View of new bridge from the East Leveecrest, looking south across the Floodway. Spacing between the pier bents varies from 100 to 120.


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Construction of the 6-lane replacement bridge began in late 2006 with demolition ofthe easternmost lanes of the old bridge. Pier construction began in May 2007. However,several months of near record precipitation during the summer of 2007 resulted in substantialconstruction delays. CESWF personnel were onsite the entire time that the pier constructionwithin the levee template was ongoing. On the east levee, Bents 30, 31 and 32 penetratethe levee cross-section (see Figure 3); while the west levee was penetrated by Bents 4 and 5(see Figure 4). Each bent consisted of eight 42-inch diameter piers socketed into theunderlying unweathered clay shale. CESWF required that all levee piers be drilled usingslurry to minimize the potential for hole collapse.

Figure 3 - Hampton Bridge, East Levee. Construction drawing showing location of Pier Bents 30,31 and 32 with respect to the east levee cross-section. Pier Bent 30 is at the wet side levee toe, Bent31 is through the crest, and Bent 32 is at the dry side toe of the levee.


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Figure 4 - Hampton Bridge, West Levee. Construction drawing showing location of Pier Bents 4and 5 with respect to the west levee cross-section. Pier Bent 5 is at the wet side levee toe.

PHOTO 20a - 27 June 2008, Hampton Bridge,East Levee. View of new bridge with respect tolevee crest looking downstream (east). Thelevee and levee crest are wider in this area due

to the access road at the dry side levee toe.

PHOTO 20b - 27 June 2008, Hampton Bridge,East Levee. Close-up view of new bridgeshowing that the clearance over the levee issufficient for passenger vehicles to travel across

the crest. Large SSD equipment must still utilizeaccess along the dry side levee toe (left).


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5.3.3.3.4 Woodall-Rodgers Bridge. Also known as the Margaret Hunt Hill Bridge, thisbridge is currently under construction. Construction of this bridge was approved by CESWFin January 2006, prior to issuance of Section 408 policy guidance in October 2006. Thisbridge has inadequate clearance above the levee crest, so access for maintenance andsurveillance is restricted. CoD should come up with a plan for adequate O&M, surveillance,and flood-fighting for this area. Mitigation measures now need to be incorporated into itsdesign to address impacts of the penetrations on the levee and its foundation. This is asignificant concern since large amounts of sand were encountered during pier construction.

Figure 5 - Woodall Rodgers Bridge, East Levee. Construction drawing showing location of PierBents 10, 11 and 12 with respect to the east levee cross-section. Pier Bent 10 is at the wet sidelevee toe, Bent 11 is through the crest, and Bent 12 is at the dry side toe of the levee.

Figure 6 - Woodall Rodgers Bridge, West Levee. Construction drawing showing location of PierBents 1 and 2 with respect to the west levee cross-section. Pier Bent 2 penetrates the wet side leveeslope above the 100-year flood elevation. Bent 1 penetrates the dry side levee slope.

4 84 DIA.

4 84 DIA.


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PHOTO 24 - 3 December 2007, Woodall Rodgers Bridge Construction on West Levee. View ofbridge construction from the left bank of the Trinity River. Note the large amount of sand exposed onthe right descending river bank during the flooding in 2007. The channel slopes in this area need tobe cleared of vegetation, regraded, and then rip-rapped to prevent erosion.

PHOTO 25a - 28 June 2007, Woodall RodgersBridge, East Levee. Although directed to do so,the bridge contractor failed to remove equipmentand materials from the Floodway when floodingwas predicted.

PHOTO 25b - 15 April 2008, Woodall RodgersBridge, West Levee. Construction of this bridgerevealed large quantities of sand that extendunder the levees.


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5.3.4 Gate Closures. Both gate closures at the east levee are damaged, resulting in a ratingof unacceptable. It is also noted that the section of floodwall closed by these stop logclosures is approximately two feet below SPF.

5.3.4.1 Closure under DART Bridge. The gate closure under the DART Bridge wasdamaged when Union Pacific Rail Road (UPRR) personnel removed the sills to facilitateaccess to their tracks. The damage is reported to date back to a train derailment in the1990s.

PHOTO 26a - 3 December 2007, Gate Closure,East Levee. Located under the DART Bridge,

this gate closure has been damaged and the sillsremoved to facilitate access to the railroad. Viewis of the left side of the gate closure, lookingnorthwest.

PHOTO 26b - 3 December 2007, GateClosure, East Levee. View of right side of

closure looking southeast. This section of thewall and closure was reconstructed after it wasdamaged by a train derailment. However, thesills were not replaced.

PHOTO 27 - 3 December 2007,Gate Closure, East Levee. As aninterim measure, sand is stockpiledadjacent to the gate closure in theevent of flooding. Stockpile iscovered with vegetation.


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PHOTO 30a (left) and 30b (right) - 3 December 2007, Dallas Floodway. Trespassers on 4-wheelers use the Floodway (photo left) and Levees (photo, right) as an ATV course. Rutting on theface of the levee requires repair to prevent the development of erosion gullies.

5.3.7 Rochester Levee. Constructed by the CoD in 1993, this system of the DallasFloodway project became part of the Federal project in 1999 under the direction ofCongress. The December 2007 PI was the first inspection of the Rochester Levee.

5.3.7.1 Mechanically Stabilized Earth Wall. A Mechanically Stabilized Earth (MSE)wall constitutes the wet side of the northeast levee and is approximately 600 feet long.Rotation of the wall reportedly began soon after construction was complete. Measurementsindicated that the rotation at the top of the wall is approximately 0.6 foot. The rotation of thewall and misaligned guardrail that runs along the crest of the wall/levee indicates that thewall is in active failure. The condition of this system of the Dallas Floodway is unacceptable.

PHOTO 31a - 4 December 2007, RochesterLevee. The Rochester Levee partially rings asmall lake that is a popular recreation site for thelocals. The levee/MSE wall is to the left.

PHOTO 31b - 4 December 2007, RochesterLevee. Guardrail runs along the crest of thenortheast edge of the Rochester Levee. Thisportion of the levee is a combination of earthenlevee and MSE wall.


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PHOTO 32 - 4 December 2007, Rochester Levee. The northeast corner of the Rochester Levee isa combination of earth (dry side) and MSE wall (wet side). The wall is rotated outward at the top~0.6 and appears to be in active failure. A close-up of the corner of the wall is shown in Photo 33.

PHOTO 33 - 4 December 2007, Rochester Levee. Thecorner of the MSE wall has pulled apart and rotated outwardat the top. This opening would allow ready access to floodwaters, which could contribute to failure of the levee during aflood event. CoD has reportedly monitored the movementsof the wall since construction was completed in 1993.Results of the surveys should be provided to SWF for review.


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PHOTO 34 - 4 December 2008,Rochester Levee. Erosion adjacent tothe Rochester Levee outlet needs to berepaired.

5.3.7.2 Railroad Closures and Sheet Pile Wall. Three active railroad closures arelocated at Rochester Levee. One of those structures has had the sill partially removed and isin unacceptable condition.

Another of the Rochester closures includes approximately 1,100 feet of sheet pile thatruns along the crest of the levee adjacent to the UPRR line. The purpose and design of thiswall are unknown but, since it is higher than the adjacent levee, there is a concern thatoutflanking the sheet pile during a flood event would concentrate flows sufficient to erode theadjacent levee. It is reported that the top of the sheet pile is the top of protection. If that isthe case, then the height of the protection is deficient. Additionally, desiccation of the soiladjacent to the sheet pile creates a preferential seepage path that would allow infiltration ofsurface water. CoD should provide SWF the design documents of the sheet pile wall forreview.

PHOTO 35 - 4 December 2008,Rochester Levee. Thisrailroad closure includesapproximately 1,100 feet ofsheet pile that runs along thecrest of the levee adjacent tothe UPRR line. Note that thetop of the sheet pile isapproximately a foot higher thanthe adjacent levee.


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5.3.8 Central Wastewater Treatment Plant (CWWTP). Constructed by the CoD in the1990s, this system of the Dallas Floodway project became part of the Federal project in1999 under the direction of Congress. The December 2007 PI was the first inspection of theRochester Levee.

The levee around the CWWTP is in generally good condition with no erosion orsettlement observed. However, the hundreds of penetrations associated with CWWTPbuildings, equipment, and utilities are a concern with respect to levee integrity andperformance. Additionally, desiccation cracking was evident adjacent to many of thesepenetrations. Because of this, this system of the project is rated as Unacceptable. Typicalpenetrations are shown in the following photos.

PHOTO 36a - 4 December 2007, CWWTP. Thelevee that rings the CWWTP is riddled withpenetrations, including transmission towerfoundations, structures, and fences. Theprotected (dry) side is to the left.

PHOTO 36b - 4 December 2007, CentralWaste Water Treatment Plant. Desiccationcracking adjacent to the fence that runs alongthe crest of the levee. Cracking at the time ofthe inspection was 1 wide.

PHOTO 37a - 4 December 2007, CWWTP.Transmission tower foundations, structures, anddrainage ditches are items of concern withrespect to levee performance.

PHOTO 37b - 4 December 2007, CentralWaste Water Treatment Plant. Tanks at thesanitary plant penetrate the levee template.The dry side of the protection is to the right.


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5.4 DESIGN CRITERIA REVIEW.

5.4.1 East and West Levees. Significant changes in the state of practice have occurredsince USACE reconstructed the Dallas Floodway project Levees in the 1950s. Additionally,explosive, uncontrolled growth adjacent to the Dallas Floodway project has resulted in landuse changes that have increased flood heights. In order to insure acceptable performance atauthorized design levels, the East and West Levee systems need to be upgraded to meetcurrent design standards. Substantial data gaps that must be resolved before a completeassessment of the project with respect to current criteria include limited subsurface data withwhich to evaluate the project features, unavailable as-built conditions of existing structures inand near the levee template, and determination of time and weather impacts on the strengthand physical properties of the levee materials.

5.4.1.1. Stability. As constructed by the CoD in the 1920s, the levees comprising theDallas Floodway project had side slopes of 2.5H:1V, a crest width of 6 feet, and a maximumheight of 35 feet. USACE-constructed modifications performed in the 1950s includedflattening the existing 2.5H:1V slopes to 3H:1V or flatter (up to 4H:1V) and wideningthe crest from 6 to 16 feet. As shown on Figures 7 and 8, most of the additional fillmaterial added to the levee slopes was placed on the riverside of the levees. Prior

to placement of additional material, the levee was stripped to a depth of 6 inchesand the top 4 feet of the embankment removed to facilitate construction of the widercrest.

Figure 7. Typical Cross-Section of East Levee Modifications

Review of design documentation from the 1950s indicates that the levees weredesigned for a minimum Factor of Safety for stability of 1.3. For the Steady State Seepagecondition that generally controls levee design, current criteria presented in EM 1110-2-1913require a Factor of Safety of 1.4.


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Figure 8. Typical Cross-Section of West Levee Modifications

5.4.1.2 Seepage. As shown on Figures 7 and 8, USACE did not include cut offmeasures into the design of levee modifications. Design documentation indicates thatUSACE relied on the impervious blanket found across much of the Floodway to protectagainst seepage-related problems. Unfortunately, numerous activities within the Floodway

unrelated to flood control have compromised the blanket. Additionally, recent investigationsindicate that the presence of high permeability soils is more widespread within the Floodwayand under the levees than originally indicated by investigations conducted for the design oflevee re-construction performed by USACE in the 1950s.

It is noted that underseepage analyses performed by others for the design ofmitigations necessary for proposed projects (including bridges and pump stations) within theFloodway indicate critical gradients as high as 2.0 can be expected in some areas of theFloodway. These values are substantially greater than the 0.5 allowed under ETL 1110-2-569, and indicate that a closer look, to include extensive subsurface investigations of theFloodway and existing levees, is needed to evaluate this project under current criteria.

5.4.1.3 SPF. A survey of the levee crest in 2003 confirmed that the levee height isinsufficient to accommodate the authorized protection level of SPF + 4 (see Appendix H).

It is important to note that CESWF began studies in earnest in 2004 to evaluate thefeasibility of bringing the Dallas Floodway project into compliance with current Hydraulic,Hydrology, Geotechnical and Structural design criteria. CoD successfully lobbied Congressfor the Balanced Vision Plan (BVP), which included improvements for flood damagereduction and interior drainage. The BVP was authorized by WRDA 2007 predicated onCoDs ability to demonstrate that the recreational components of the plan would not have a


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negative impact on the flood damage reduction function of the Floodway. Included in the$459M WRDA 2007 appropriation was flood damage reduction benefits to an SPF + 2 level.

Although it is CESWFs intent to evaluate the existing Floodway and designmeasures to bring it into compliance with current criteria using funding from the WRDA 2007authorization, CESWF believes that the $459M authorization is insufficient to allowconstruction of all the expected upgrades to the Floodway, including those necessary toinsure that the flood risk management project is in compliance with current USACE designcriteria. See Table 1 for additional discussion and recommendations associated withaddressing levee safety issues necessary to achieve an overall acceptable rating for theFloodway.

5.4.2 Encroachments. Hundreds of encroachments within the Floodway reduce the level offlood protection, impact access for O&M, restrict the ability to make repairs due to restrictedclearance, and provide pathways for water that can contribute to seepage and stabilityproblems. According to the Levee Checklist, such penetrations are considered to beunacceptable unless mitigations to offset the negative impacts have been incorporated intotheir design. Examination of available information from USACE design and constructiondocumentation does not indicate that any redundancies were incorporated into the project to

account for the impacts of bridges.

Each encroachment identified within the Floodway needs to be evaluated todetermine its im

CORP OF ENGINEERS PERIODIC INSPECTION REPORT DALLAS FLOODWAY TRINITY RIVER

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