La Marque-Hitchcock Extension)

Documents Department Oldihoma State University Library

=TEXAS CITY AND VICINITY, TEXAS (LA MARQUE-HITCHCOCK EXTENSION)

LETTER FROM THE SECRETARY OF THE ARMY TRANSMITTING

A LETTER FROM THE CHIEF OF ENGINEERS, DEPART- MENT OF THE ARMY, DATED DECEMBER 16, 1966, SUB- MITTING A REPORT, TOGETHER WITH ACCOMPANYING PAPERS AND ILLUSTRATIONS, ON A REVIEW OF THE REPORT ON TEXAS CITY AND VICINITY, TEXAS (LA MARQUE-HITCHCOCK EXTENSION), HURRICANE FLOOD PROTECTION, REQUESTED BY A RESOLUTION OF THE COMMITTEE ON PUBLIC WORKS, HOUSE OF REPRE- SENTATIVES, ADOPTED MAY 10, 1962

NOVEMBER 29, 1967.-Referred to the Committee on Public Works and ordered to be printed with illustrations

U.S. GOVERNMENT PRINTING OFFICE WASHINGTON : 1967 86-965 0

. . t6 1"X ?t CONTENTS

Page Letter of transm ittal_- _------_ -_-_-_-_-_-_-_-_--- _-_ - v Comments of the Bureau of the Budget_ vi Comments of the Governor of Texas____ vii Letter to the Governor of Texas______viii Comments of the Department of the Interior- ix Letter to the Secretary of the Interior______xi Comments of the Department of Commerce_ xii Report of the Chief of Engineers, Department of the Army - 1 Report of the Board of Engineers for Rivers and Harbors- 3 Report of the District Engineer: Syllabus ____-______10 Introduction: Scope - ______11 Arrangement of report- 11 History of investigations_ 12 O ther reports -_ _-_-_-_-_------12 Authority for this investigation_ 12 Public hearing -_-_-_-_-_- 12 Improvements desired____ 12 Area description: General location and size- 13 Physical characteristics of the area- 13 Climatology: Climatological data 13 Precipitation_ 13 Tropical storms-_-_- 14 Storm history _ _ _ _ 14 Storm tides ______14 Storm tide frequencies_ 15 Design rainfall frequencies with high tides_ 15 Design and rainfall frequencies with normal tides- 16 Extent and character of flooded area: Area subject to flooding______16 Flood damages__ _ _ _- ______17 Economic development: Early developm ent _-_ -__-_-_-- - --_-_- _-_---_-_-_------17 Recent development of mainland area____ 18 Character of physical development_____ 18 Existing Corps of Engineers' projects: Existing flood control project - _-_-- - -_-_------19 Existing navigation project______19 Existing hurricane flood protection project 19 Project formulation: Plans investigated --_ - - _-_-_-_------20 __ __ Comparison of plans- _ _ _ - 22 Selection of plan .- ______23 Plan of improvement _------_-----_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_--- 23

iii Report of the District Engineer-Continued Economic evaluation of project: Page G eneral..______25 Estimates of first cost------25 Estimates of annual charges- 25 Benefits ------_-_- - - -- 26 Prevention of damages- 26 Residual damages------27 Summary of benefits_ 27 Comparison of benefits and costs- 27 Apportionment of costs: Apportionment of costs among interests- 28 Local cooperation: Proposed local cooperation------29 Coordination with other agencies: Initiation of studies _____- 30 U.S. Fish and Wildlife Service------32 U.S. Public Health Service------32 U.S. Soil Conservation Service - 32 U.S. Bureau of Mines_____------32 D iscu ssion -_ -__ -__ -__ _-__-__ _-__--__ _ 33 Conclusions ______36 Recom m endations _-_-_ _-_--- _-----_-_-_-- _--_- 37 Recommendations of the Division Engineer- _--_- 39

APPENDIXES ACCOMPANYING THE REPORT OF THE DISTRICT ENGINEER Appendix: Page I. Hydrology and Hydraulics______41 II. Project Evaluation 75 III. Engineering and Cost Data______87 IV . Com m ents by O ther Agencies______----______-- _____-______105

ATTACHMENT.--Information Called for by Senate Resolution 148, 85th Congress, Adopted Jan uary 28, 1958 __- _---- __- _- _---- _-_ _- _____------__- _--- _- __- _-_ - _ 120

ILLUSTRATIONS ACCOMPANYING THE REPORT OF THE DISTRICT ENGINEER (Only Plates 1 and 2 printed) Plate 1. Index Map. Plate 2. Plan of Improvement, Plan C. Plate 3. Plans investigated.

iv LETTER OF TRANSMITTAL

DEPARTMENT OF THE ARMY WASHINGTON, D.C. 20310

November 21, 1967

Honorable John W. McCormack Speaker of the House of Representatives Washington, D. C. 20515

Dear Mr. Speaker:

I am transmitting herewith a favorable report dated 16 December 1966, from the Chief of Engineers, Department of the Army, together with accompanying papers and illustrations, on a review of the report on Texas City and Vicinity, Texas (La Marque-Hitchcock Extension), Hurricane Flood Protection, requested by a resolution of the Committee on Public Works, House of Representatives, adopted 10 May 1962.

The views of the Governor of Texas and the Departments of the Interior and Commerce are set forth in the inclosed communications, together with the replies of the Chief of Engineers to the Governor of Texas and the Secretary of the Interior.

The Bureau of the Budget advises that there is no objection to the submission of the proposed report to the Congress; however, it states that no commitment can be made at this time as to when any estimate of appropriation would be submitted for construction of the project, if authorized by the Congress, since this would be governed by the President's budgetary objectives as determined by the then prevailing fiscal situation. A copy of the letter from the Bureau of the Budget is inclosed. Use of the currently prescribed interest rate of 3-1/4 percent in computing annual charges and benefits would result in no appreciable change in the benefit-cost ratio.

Sincerely yours,

1 Incl STANLEY R. RESOR Report Secretary of the Army

V COMMENTS OF THE BUREAU OF THE BUDGET

EXECUTIVE OFFICE OF THE PRESIDENT BUREAU OF THE BUDGET WASHINGTON, D.C. 20503

November 6, 1967

Honorable Stanley R. Resor Secretary of the Army Washington, D. C. 20310

Dear Mr. Secretary:

Mr. Alfred B. Fitt's letter of October 4, 1967, submitted the favorable report of the Chief of Engineers on Texas City and Vicinity, Texas (La Marque-Hitchcock Extension), Hurricane Flood Protection, requested by a resolution of the Committee on Public Works, House of Representatives, adopted May 10, 1962.

I am authorized by the Director of the Bureau of the Budget to advise you that there would be no objection to the submission of the proposed report to the Congress . No commitment, however, can be made at this time as to when any estimate of appropriation would be submitted for construction of the project, if authorized by the Congress, since this would be governed by the President's budgetary objectives as determined by the then prevailing fiscal situation.

Si erely yours,

Car c wartz, Jr. Dotector, Natural Resources Programs Division

vi COMMENTS OF THE GOVERNOR OF TEXAS

JOHN CONNALLY

GOVERNOR OF TEXAS

November 30, 1966

Lieutenant General William F. Cassidy Chief of Engineers Department of the Army Washington, D. C. 20315

Dear General Cassidy:

On June 2 you wrote me concerning the report of the Chief of Engineers on Texas City and Vicinity, Texas (La Marque-Hitchcock Extension), Hurricane Flood Protection. During the past several months I have had intensive studies made of this proposed project.

It is my recommendation that this project be authorized but that the final decision include provisions to minimize losses to the fish habitat in Jones Bay and to mitigate pollution of the Bay water inside of the project structures.

Both the United States Department of Interior and the Texas Parks and Wildlife Department have called attention to the desirability of additional tidal-interchange structures and the desirability of obtaining fill material for construction of a levee from areas immediately adjacent to the levee to accomplish the objectives cited above. We concur in these comments and request that the final design of the project reflect these changes.

I appreciate the opportunity to comment on this project.

With kindest regards,

incerely,

J n Gonna ly

vii LETTER TO THE GOVERNOR OF TEXAS

\ *I ' DEPARTMENT OF THE ARMY \ / OFFICE OF THE CHIEF OF ENGINEERS WASH INGTON, D.C. 20315

IN REPLY REFER TO ENGCW-.PD 9 December 1966

Honorable John Connally Governor of Texas Austin, Texas

Dear Governor Connally:

Thank you for your recent letter commenting on the proposed report of the Chief of Engineers on Texas City and Vicinity, Texas (La Marque- Hitchcock Extension).

You called attention to the desirability of additional tidal- interchange structures and of obtaining fill material for construction from areas immediately adjacent to the levee in the final design..I assure you that consideration will be given to these suggestions in the advance planning stage, if the project is authorized.

Sincerely yours,

WILLIAM F. CASSIDY Lieutenant General, USA Chief of Engineers

viii COMMENTS OF THE DEPARTMENT OF THE INTERIOR EN1i OF Ty UNITED STATES A DEPARTMENT OF THE INTERIOR OFFICE OF THE SECRETARY "h3,WASHINGTON, D.C. 20240

19 August 1966

Dear General Cassidy:

This is in reply to your letter of June 2, 1966 requesting our comments on reports on Hurricane Flood Protection, Texas City and Vicinity, Texas.

The Fish and Wildlife Service is pleased that the plan for the hurricane barrier across Jones Bay has been modified to provide substantial protection for fish and wildlife habitat. However, it believes that additional modification of the plan is feasible and warranted. The Service recommends that consideration be given to the inclusion of additional culverts in the levee to provide, as near as possible, normal tidal exchange. It also is suggested that treated sewage effluent from the bayous be diverted to open bay water. Further, fish and wildlife habitat in the project area would be subject to destruction if borrow and spoil areas are not selected judiciously. This matter should be reviewed thoroughly during the preconstruction planning period.

The Federal Water Pollution Control Administration advises that reasonable consideration now appears to be given to potential pollution problems in the Jones Bay area. Provision of additional gated tidal outlets from the barrier as called for by the Fish and Wildlife Service should minimize the adverse effects of the tidal exchange.

As noted in the District Engineer's report, population and industrial growth of small areas cannot be predicted with great accuracy. Problems would be expected to develop in the Jones Bay area as development takes place, although these can be controlled for a time by proper collection and treatment by available methods. Eventually, however, nutrients will result in problems requiring advanced waste treatment or disposal of treated effluents outside the Jones Bay area if unsatisfactory water quality as regards algal blooms and consequent fluctuating DO levels are to be avoided. Regardless of whether or not the barrier is installed, additional control measures will eventually be required.

ix Wastes from the area would, of course, cause extremely poor conditions if not effectively collected and treated. Therefore, a requirement that adequate collection, secondary waste treatment, and eventually advanced waste treatment or appropriate effluent dispersion facilities beyond the barrier as needed by the growth of the area and the effects of the wastes on water use for commercial and sports fishery should be added as an item of local cooperation.

The opportunity of presenting our recommendations is appreciated.

Sincerely yours,

Deputy Assistant Secretary of the Interior

Lt. General William F. Cassidy Chief of Engineers Department of the Army Washington, D. C. 20315

x LETTER TO THE SECRETARY OF THE INTERIOR

\ I DEPARTMENT OF THE ARMY

. \ / OFFICE OP THE CHIEFOP FENGINEERS WASHINGTON, D.C. 20315

IN REPLY REFER TO ENGCW-PD 11 October 1966

The Honorable Stewart L. Udall

The Secretary of the Interior

Dear Mr. Secretary:

This is in reply to the recent letter from the Department of the Interior furnishing comments on the proposed report of the Chief of Engineers on Texas City .and Vicinity, Texas (La Marque-Hitchcock Extension).

The Department's letter suggests the possibility that, as future development occurs in the Jones Bay area, problems of water quality will increase which will require more stringent controls upon the disposal of effluents regardless of whether or not the proposed barrier is installed. The letter further suggests adding a requirement of cooperation as part of the Corps project that local interests provide such additional waste control measures as may be needed as a result of this development.

In view of the fact that the need for the above-mentioned waste control measures is not dependent on the proposed barrier, the suggested item of local cooperation is considered to be inappropriate.

The comments of the Department of the Interior together with this reply, will accompany this report when it is transmitted to Congress.

Sincerely yours,

(Signed)

WILLIAM F. CASSIDY Lieutenant General, USA Chief of Engineers

xi COMMENTS OF THE DEPARTMENT OF COMMERCE

OFFICE OF THE UNDER SECRETARY OF COMMERCE * * FOR TRANSPORTATION WASHINGTON, D.C. 20230 r7ES ofSeptember 19, 1966

Lieut. General William F. Cassidy, USA Chief of Engineers Department of the Army Washington, D.C. 20315

Dear General Cassidy:

You invited this Department's comments on your proposed report and accompanying reports concerning the advisability of modifying the existing hurricane flood protection project for Texas City and vicinity, Texas.

You recommend that the existing hurricane flood protection project for Texas City and vicinity, Texas, be modified to extend southward and westward to provide the same degree of protection to adjacent areas of La Marque and Hitchcock, Texas; this can be done by construction of about 11.41 miles of earth levee with related drainage and closure structures and a navigation and tidal control structure in Jones Bay, at an estimated first cost for extension of the project at $18,220,000, the net additional cost of the modification at $15,700,000, the annual charges at $597,000, and the annual benefits at $886,000 and the benefits - cost ratio is 1.4.

The Bureau of Public Roads reports that a closure structure and road ramp would be provided where the proposed levee alignment crosses State Route 6 (FAP 83) at a total estimated cost of $273,040, and that the cost has been made a part of the local contribution to the project. Inasmuch as State Route 6 is included in the Federal-aid system, the local sponsors should be advised that Federal-aid highway funds cannot be used to finance any part of the cost of the highway alteration.

The Weather Bureau finds that the meteorological portion of the report is correct.

The Department concurs in your findings and appreciates the opportunity to review and comment on your report. Sincerely,

Lowell K. Bridwell Deputy Under Secretary for Transportation TEXAS CITY AND VICINITY, TEXAS (LA MARQUE-HITCHCOCK EXTENSION)

REPORT OF THE CHIEF OF ENGINEERS, DEPARTMENT OF THE ARMY

DEPARTMENT OF THE ARMY OFFICE OF THE CHIEF OF ENGINEERS WASHINGTON, D.C. 20315

IN REPLY REFER TO

ENGCW-PD 16 December 1966

SUBJECT: Texas City and Vicinity, Texas (La Marque-Hitchcock Extension)

TO: THE SECRETARY OF THE ARMY

1. I submit for transmission to Congress the report of the Board of Engineers for Rivers and Harbors, accompanied by the reports of the District and Division Engineers, in response to a resolution of the Committee on Public Works of the House of Representatives, United States, adopted 10 May 1962, concerning the advisability of modifying the existing hurricane flood protection project for Texas City and vicinity, Texas, particularly with a view to extending the hurricane flood protection including hurricane tides in a south and westerly direction to provide protection to the western portion of La Marque, Hitchcock, and the adjacent area along Highland Bayou, Texas.

2. The District and Division Engineers recommend that the existing hurricane flood protection project for Texas City and vicinity, Texas, be modified to extend southward and westward to provide the same degree of protection to adjacent areas of La Marque and Hitch- cock, Texas, by construction of about 11.4 miles of earth levee with related drainage and closure structures and a navigation and tidal control structure in Jones Bay. The modification would eliminate the need for the La Marque pumping plant and adjoining levee extending northwesterly on the westerly side of Interstate Highway 45. The foregoing recommendation is subject to the condition that if local interests do not provide firm assurances of local cooperation within

1 three years from the date of the authorizing legislation, or, if prior to the end of the three-year period local interests serve formal notice that they cannot provide the local cooperation, authority for the recommended modifications shall expire and the project shall revert to its original authorization under Section 203 of the Flood Control Act approved 3 July 1958. Local interests would then be credited with the fair value of any usable work accomplished entirely by them westward of Interstate Highway 45 which is subsequently utilized in completion of the original project. The District and Division Engineers estimate the first cost for extension of the project at $18,220,000, the net additional cost of the modification at $15, 700, 000, the annual charges at $597, 000, and the annual benefits at $866, 000. The benefit- cost ratio is 1.4. The total cost of the new work is apportioned 70 percent Federal and 30 percent non-Federal in accordance with the cost apportionment prescribed for the authorized project. The additional Federal cost is presently estimated at $10,990,000 and the additional non-Federal cost at $4,710,000, consisting of $706,000 for lands and relocations, and a cash contribution of $4,004,000.

3. The Board of Engineers for Rivers and Harbors concurs in general in the views and recommendations of the reporting officers. The Board notes, however, that the actual first cost of the proposed extension is estimated at $18,220,000, of which local interests would be required to contribute 30 percent. On that basis the non-Federal cost would be $5,466,000, consisting of $706,000 for lands and relocations and a cash contribution of $4,760,000. The Board has carefully considered the possibilities of windfall-type benefits and believes that the benefits are not of such character as to require a special local contribution beyond that normally required for hurricane protection projects. The Board notes the comments of the United States Public Health Service that the restriction of flow to and from Jones Bay may result in an unsatisfactory water quality condition, and believes that, prior to construction, consideration should be given to any practical measures to reduce or prevent deterioration of water quality. The Board recommends that the existing project for hurricane flood protection for Texas City and vicinity, Texas, be modified generally in accordance with the plans of the District Engineer at an estimated additional cost to the United States of $10,990,000 subject to certain local cooperation.

4. I concur in the views and recommendations of the Board.

WILLIAM F. CASSIDY Lieutenant General, USA Chief of Engineers 2 REPORT OF THE BOARD OF ENGINEERS FOR RIVERS AND HARBORS

DEPARTMENT OF THE ARMY CORPS OF ENGINEERS BOARD OF ENGINEERS FOR RIVERS AND HARBORS WASHINGTON, D.C. 20315

IN REPLY REFER TO ENGBR 6 April 1966

SUBJECT: Texas City and Vicinity, Texas (La .Marque-Hitchcock Extension), Hurricane Flood Protection

TO: Chief of Engineers Department of the Army

1. Authority.--This report is in response to the following resolution adopted 10 May 1962:

Resolved by the Committee on Public Works of the House of Representatives, United States, That the Board of Engineers for Rivers and Harbors be, and is hereby, requested to review the report on Texas City and Vicinity, Texas, submitted in House Document numbered 347, Eighty- fifth Congress, Second Session, with a view to determining the advisability of modifying the existing project in any way at this time, particularly with a view to extending the hurricane-flood protection including hurricane tides in a south and westerly direction to provide protection to the western portion of La Marque, Hitchcock, and the adjacent area along Highland Bayou, Texas.

2. Description. -- The cities of Texas City, La Marque, and Hitchcock adjoin each other along the westerly shore of Galveston Bay about 12 miles from the Gulf of Mexico. Texas City and a portion of La Marque will be protected from hurricane tidal flooding when construction of the authorized project for Texas City, currently in progress, is completed. The unprotected portion of La Marque and Hitchcock comprise about 28 square miles of land varying in elevation from mean sea level to 15 feet. About one-sixth of this area is presently occupied by residential and commercial development, and it is expected that the entire area lying above 7 feet elevation will be developed by the year 2065. Within the past 2 to 3 years, substantial developments of residential and summer cottages have been started in the low areas lying below 7 feet elevation. It appears that such development will increase rapidly in the near future.

3 3. Existing improvements. -- A hurricane flood protection project for Texas City and vicinity, Texas, authorized by the Flood Control Act of 1958, provides for the construction of about 18 miles of new and enlarged levees and floodwalls, together with related drainage and closure structures, a navigation and tidal control structure, and pumping plants. The area to be protected by the project lies immediately north and east of the area considered in this report. Construction of the hurricane flood protection project, initiated in 1962, is scheduled to be about 60 percent complete in June 1966. The current estimated cost for constructing the project (July 1965) is $22,600,000. Work on constructing one pumping station on the south side of La Marque, and the construction of the levee from this pumping station to the westerly terminus of the project, previously scheduled for 1964-65, has been deferred pending the results of studies in connection with this review report. In addition to the two deferred items, work remaining to complete the project, presently scheduled for construction in 1967 and 1968, consists of second stage levee construction across two water areas, construction of a short reach of levee in the vicinity of the south Texas City pumping station, and connection of the levee to the fill and other facilities of Interstate Highway 45 on the south side of La Marque.

4. A flood control project for Highland Bayou, Texas , authorized by the Flood Control Act of 1965, provides for protection from upstream flooding to Hitchcock and La Marque by improvement of the Highland Bayou channel and construction of a diversion dam with a diversion channel following generally along Basford Bayou to Jones Bay. Subse- quent to submission of the report on Highland Bayou, a large canal-city type development named Flamingo Isles was started near the mouth of Basford Bayou. It was expected that, during postauthorization- planning, the diversion channel would be rerouted to Greens Lake in lieu of the originally planned route along Basford Bayou. No planning or construction funds for the authorized project have been appropriated. Further modification of the diversion channel outlet of the authorized flood control project will be required by the hurricane flood protection improvements considered in this report.

5. Hurricane flood damages.--In the 86-year period from 1879 through 1964, 45 hurricanes have affected the Texas coast, an average of about one every 2 years . The average frequency with which any point

4 on the Texas coast may be subjected to storms of hurricane intensity is estimated to be once in 9.2 years. Severe hurricanes have caused tides of 15 feet above mean sea level in the Galveston Bay area. Hur- ricane "Carla" in September 1961 produced surge heights from 10 feet to 13 feet above mean sea level in the unprotected La Marque-Hitchcock area and caused flood damages of approximately $2, 350, 000. Under present conditions the occurrence of a hurricane flood tide of 15 feet above mean sea level would cause damages in this area estimated at $6, 375,000. Average annual damages from hurricane flooding under existing conditions are estimated at $266,000.

6. Improvement desired.--Local interests desire that the authorized Texas City and vicinity, Texas, hurricane flood protection project be extended to protect the western section of La Marque and the adjacent city of Hitchcock from damages associated with hurricane floods. They have expresses willingness to cooperate in the improvements.

7. Plan of improvement. -- The District Engineer finds that the most practicable plan of improvement would provide for enclosure of the La Marque-Hitchcock area by about 11.4 miles of earth levee, with related drainage and closure structures and a gated navigation and tidal control structure in Jones Bay. The levee would join the authorized Texas City hurricane flood protection project near its junction with Interstate Highway 45, and extend southward and westward to terminate on high ground south of Hitchcock. The authorized La Marque pumping station and adjoining levee extending northwesterly on the westerly side of Interstate Highway 45 would be eliminated from the Federal project. Construction of the proposed levee and appurtenant structures would prevent most of the damages that would result from high tides in the area protected. The degree of protection provided would be identical to that afforded by the authorized project, i.e., protection from a design hurricane with an estimated recurrence interval of about 100 years.

8. The sponsoring local agency for both the authorized project and the proposed modification feels that construction of the levee westward from Interstate Highway 45 should not be delayed pending the construction of the improvements in the proposed modification, but agrees that construction of the La Marque pumping station could be deferred without

86-965 0-67-2 serious risk. Therefore, to prevent even temporary prolongation of exposure of the area that would be protected by the west leg of the authorized project, the sponsoring agency has stated its intention to construct at least a temporary levee, using non-Federal funds entirely to do so. They plan to build the levee and such drainage structures as are absolutely essential, by 1968, on the same alignment and to the same elevation as the levee planned under the authorized project. If this is done and if, for any reason the proposed modification.cannot subsequently be constructed, local interests expect the project as now authorized, including the La Marque pumping station, to be completed. In that event, they desire and expect to be credited with the actual cost of usable work performed to be part of the local cooperation requirements for the existing project. To the extent that any such work performed could be utilized in the completed project, the desires of local interests are considered reasonable.

9. Accordingly, the District Engineer recommends modification of the existing project for hurricane flood protection for Texas City and vicinity, Texas, to extend southward and westward and afford the same degree of protection to adjacent areas in the western part of La Marque and,Hitchcock, Texas, generally as described in his report, with such modifications thereof as in the discretion of the Chief of Engineers may be advisable, and that the levees, pumping station, drainage structures, and other features of the existing project westward of Interstate Highway 45 not be built as a part of the Federal project if the proposed modification is constructed. The recommendations of the District Engineer are subject to certain provisions of local cooperation and to the condition that, if local interests do not provide the required local cooperation within three years from the date of the authorizing legislation, or, if prior to the end of the three-year period local interests serve formal notice that they cannot provide the local cooperation, authority for the recommended modifications shall expire and the project shall revert to its original authorization under Section 203 of the Flood Control Act approved 3 July 1958. Then, and in that event local interests would be credited with the actual cost of any usable work accomplished entirely by them on the original project westward of Interstate Highway 45 which is subsequently utilized in completion of the original project.

10. Costs and justification.--Based on December 1965 prices, the estimated total first cost of the proposed modification in the plan of

6 improvement is $18, 220, 000, of which $12, 754, 000 would be Federal and $5,466, 000 non-Federal. Construction of the proposed modification would obviate the need for constructing a portion of the authorized project having an estimated first cost of $2,520,000, of which $1,764,000 is Federal and $756,000, non-Federal. Accordingly, the District Engineer estimates the net additional cost of the modified project at $15, 700, 000, the annual charges at $597,000, and the annual benefits at $866,000. The benefit- cost ratio is 1.4, based on a 100-year period of analysis and a 3-1/8 percent rate of interest. The total cost of the improvements is apportioned 70 percent Federal and 30 percent non-Federal in accordance with the cost apportionment prescribed for the authorized project. Based on present estimates, and taking into account the cost of that portion of the authorized project that would be eliminated, the additional Federal cost would be $10,990,000 and the additional non-Federal cost would be $4,710,000, consisting of $706,000 for lands and relocations, and a cash contribution of $4, 004, 000. Estimated additional maintenance and operation cost of $50,000 annually would be borne by the local interests. The Division Engineer concurs in the conclusions and recommendations of the District Engineer.

11. The Division Engineer issued a public notice stating the recommendations of the reporting officers and affording interested parties an opportunity to present additional information to the Board. Careful consideration has been given to the communications received.

Views and Recommendations of the Board of Engineers for Rivers and Harbors.

12. Views.--The Board of Engineers for Rivers and Harbors concurs in general in the views and recommendations of the reporting officers. The protective measures are suitable and adequate to provide needed protection against tidal flooding during hurricanes which are reasonably characteristic of the area. The proposed improvements are economically justified and the requirements of local cooperation are generally appropriate except that the local contribution for the proposed modification should be stated on the basis of the total cost of the modification rather than the net additional cost of the combination of the modification with the previously authorized project. The Board notes that this would have no effect on the total amount required to be contributed by local interests toward construction of the Federal project as a whole, such contribution being limited to 30 percent of the actual project cost, with appropriate

7 allowance for the cost of lands, rights-of-way, and relocations. The Board has carefully considered the possibilities of windfall-type benefits and believes that the benefits are not of such character as to require a special local contribution above the 30 percent normally required for hurricane protection projects.

13. The Board notes the comments of United States Public Health Service that the project will result in some public health benefits in the area, but that the restriction of flow to and from Jones Bay may result in an unsatisfactory water quality condition in the area behind the levee. The Board believes that prior to construction careful consideration should be given to any practical measures which may be taken to reduce or prevent deterioration in the quality of water in the area.

14. Recommendations. -- Accordingly, the Board recommends that the existing project for hurricane flood protection for Texas City and vicinity, Texas, be modified to extend southward and westward to afford the same degree of protection to adjacent areas in the western part of La Marque and Hitchcock, Texas, by construction of about 11.4 miles of earth levee with related drainage structures and a gated navigation and tidal control structure in Jones Bay; generally in accordance with the plan of the District Engineer and with such modifications thereof as in the discretion of the Chief of Engineers may be advisable; at an estimated first cost of $18,220,000 of which the additional cost to the United States is estimated at $10,990,000 for the combination of the modification with the previously authorized project: Provided that prior to initiation of construction, local interests furnish assurances satisfactory to the Secretary of the Army that they will:

a. Provide, without cost to the United States, all lands, easements, and rights-of-way, including all borrow areas and the relocation of buildings, pipelines, and utilities necessary for the construction of the additional work, at costs presently estimated at $706,000;

b. Bear 30 percent of the first cost, to consist of the cost of items listed in a above and a cash contribution presently estimated at $4, 760, 000 to be paid either in a lump sum prior to initiation of construction or in installments prior to start of pertinent work items in

8 accordance with construction schedules as required by the Chief of Engineers, the final apportionment of costs to be made after actual costs and values have been determined;

c. Hold and save the United States free from damages due to the construction works;

d. Maintain and operate all works after completion in accordance with regulations prescribed by the Secretary of the Army; and

e. Prohibit encroachment on improved channels or on ponding areas, and if the capacity of the ponding area is impaired, provide promptly, without cost to the United States, substitute ponding capacity or equivalent pumping capacity.

16. The foregoing recommendation is subject to the condition that if local interests do not provide firm assurances of local cooperation within three years from the date of the authorizing legislation, or, if prior to the end of the three-year period local interests serve formal notice that they cannot provide the local cooperation, authority for the recommended modifications shall expire and the project shall revert to its original authorization under Section 203 of the Flood Control Act approved 3 July 1958. In this event, local interests shall then be credited with the fair value of any usable work accomplished entirely by them on the original project westward of Interstate Highway 45 to the extent that such usable work is utilized in completion of the original project.

FOR THE BOARD:

R. G. MacDONNELL Major General, USA Chairman

9 REPORT OF THE DISTRICT ENGINEER

REVIEW OF REPORT ON TEXAS CITY AND VICINITY, TEXAS (LA MARQUE-HITCHCOCK EXTENSION) HURRICANE FLOOD PROTECTION SYLLABUS This report comprises the results of an investigation to determine the advisability of modifying the existing hurricane flood protection project for Texas City and vicinity, Texas to extend protection to the presently unprotected portion of La Marque and the adjacent city of Hitchcock. It was found that:

a. Commercial and residential developments in sections of La Marque and Hitchcock, Texas are subject to periodic damages from tidal surges and waves that accompany tropical storms. Damages from the occurrence of the design hurricane flood under existing conditions are estimated at $6,375,000. Average annual damages from tidal flooding under existing conditions are estimated at $266,000.

b. Construction of a protective levee and appurtenant structures as proposed in the plan of improvement of this report would afford material benefits by elimination of most of the damages that would result from high tides in the protected area. The degree of protection provided would be identical to that afforded by the existing authorized hurricane flood protection project for Texas City and vicinity. Average annual benefits during the life of the project are estimated at $866,000, and the improvements would be justified with .abenefits to cost ratio of l.4.

Accordingly, it is recommended that the existing hurricane flood protection project for Texas City and vicinity, Texas, be modified to provide for a southward and westward extension of earthen levees and appurtenant structures to afford protection to sections of La Marque and Hitchcock, Texas, generally as described in this report. The estimated first cost to the United States of the, recommended new work is $10,990,000. The recommendation is subject to certain provisions of local cooperation.

The Flood Control Act of October 27, 1965 authorized protection from upstream flooding on Highland Bayou for the La Marque-Hitchcock area in accordance with a plan contained in House Document No. 168, 89th Congress, 1st session. This plan provides for enlarging Highland Bayou and constructing a diversion channel to divert flow from the upper watershed. The improvements recommended in this report would be compatible in all respects with the authorized improvements for upstream flood control on Highland Bayou. The combination of improvements authorized for Highland Bayou and recommended in this report would comprise the best overall plan of flood protection for the area. 10 U. S. ARMI ENGINEER DISTRICT, GALVESTON CORPS OF 'ENGINEERS GALVESTON, TEXAS

December 17, 1965

SUBJECT: Review of Report on Texas City and Vicinity, Texas (La Marque- Hitchcock Extension), Hurricane Flood Protection

THROUGH: Division Engineer U. S. Arry Engineer Division, Southwestern Dallas, Texas

TO: Chief of Engineers Department of the Armty Washington, D. C.

INTRODUCTION

1. Scope.- This investigation comprises a study of survey scope to determine the advisability of modifying the existing hurricane flood protection project for Texas City and vicinity, Texas, to extend protection to the presently unprotected portion of La Marque and the adjacent city of Hitchcock. Detailed field surveys and office studies were made to determine the most practicable plan of improvement. The detailed field investigations consisted of topographic surveys of the area; soil investigations to determine the foundation conditions and suitability of earth materials for levee construction; surveys of utilities and pipelines crossing the area; and an economic survey to determine the damages resulting from hurricane tidal flooding.

2. During the course of the investigation, the District Engineer made a reconnaissance of the vicinity and held conferences with local interests to discuss the plan of improvement being considered and the probable requirements of local cooperation.

3. Arrangement of report.- The following sections of this report contain the results, conclusions and recommendations of the Galveston District Engineer, based upon analysis of detailed technical data and investigations reported upon in the following appendixes to this report:

Appendix I - Hydrology and Hydraulics Appendix II - Project Evaluation

Appendix III - Engineering and Cost Data Appendix IV - Comments by Other Agencies 11 4. History of investigations.- A prior report, contained in House Document No. 347, 85th Congress, 2d session, recommended construction of improvements for hurricane flood protection to Texas City and vicinity, Texas. The existing project was authorized in accordance with that document by the Flood Control Act of July 3, 1958 and provides for the construe- tion of about 18 miles of new and enlarged levees and flood walls, together with related drainage and closure structures, a gated navigation opening, and pumping plants.

5. Other reports.- The area encompassed by this survey lies almost entirely within the watersheds of Highland and Basford Bayous. A prior report on Highland Bayou, Texas, published as House Document No. 168, 89th Congress, 1st session, recommended protection from stream flooding to Hitchcock and La Marque, Texas by improvement of the Highland Bayou channel, construction of a diversion dam, and a diversion channel following generally along Basford Bayou to Jones Bay. In recommending the improvements described in House Document No. 168, the Chief of Engineers qualified the recommendation with a provision that no construction be started on the project until the effect of the proposed works for hurricane flood protection that were to be considered under this study had been determined. The recommended improvements were authorized by the Flood Control Act of October 27, 1965. Changes to this plan made necessary by additional development occurring subsequent to its preparation are discussed in paragraph 29.

6. Authority for this investigation.- This review report on Texas City and vicinity, Texas, is submitted pursuant to the following resolution adopted May 10, 1962 by the Committee on'Public Works, House of Representatives, United States:

"Resolved by the Committee on Public Works of the House of Representatives, United States, That the Board of Engineers for Rivers and Harbors be, and is hereby, requested to review the report on Texas City and Vicinity, Texas, submitted in House Document numbered 347, Eighty-fifth Congress, Second Session, with a view to determining the advisability of modifying the existing project in any way at this time, particularly with a view to extending the hurricane flood protection including hurricane tides in a south and westerly direction to provide protection to the western portion of La Marque, Hitchcock, and the adjacent area along Highland Bayou, Texas."

7. Public heari.- A public hearing was held at Hitchcock, Texas, on January , 1963 to ascertain the desires and views of local interests regarding the extension of the Texas City hurricane flood protection project to include the La Marque-Hitchcock area. About 200 persons in- eluding Federal, County, and local officials, representatives of business interests and other interested persons attended the public hearing.

8. Improvements desired.- At the public hearing, the Galveston County Commissioners' Court requested that the authorized Texas City

12 hurricane flood protection project be extended to protect the western section of La Marque and the adjacent city of Hitchcock from the damages that are associated with hurricane floods. Local interests proposed an alignment that would join the authorized project near Texas Highway Loop 197 and extend south and west to encompass the study area. In a letter dated February 20, 1963, the commissioners' court modified its request by proposing an alignment that would join the authorized project at the pump station located near Interstate Highway k5.

AREA DESCRIPTION

9, General location and size.- The cities of Texas City, La Marque, and Hitchcock, in Galveston County, Texas, adjoin each other along the westerly shore of Galveston Bay about 12 miles from the Gulf of Mexico. Texas City and portions of La Marque would be protected from hurricane tidal flooding by the authorized Texas City project currently under construction. The unprotected area covered by this study includes an additional area of about 28 square miles, as shown on plate 2.

10. Physical characteristics of the area.- The land surface slopes gently from an elevation of abcut 20 feet to mean sea level at Jones and West Bays. The only significant irregularities in the slope are the channels cut by the bayous and excavated drainage ditches. At this time the developed areas generally occupy ground ranging from 7 feet to 15 feet in elevation. All elevations in this report refer to U. S. Coast and Geodetic Survey mean sea level datum.

CLIMATOLOGY

11. Climatological data.- The proximity of the area to the Gulf _f Mexico, the prevalence of southerly winds, and the absence of pronounced geographic relief features result in a uniform climate, with high relative humidity, warm summers, and mild winters. Freezing temperatures are infrequent and of short duration. Data from the U. S. Weather Bureau station at Galveston, Texas, about 11 miles southeast from the area, indicates that the mean annual temperature is 70.1 degrees Fahrenheit. Temperatures have ranged from a summer maxim of 101 degrees to a winter minimum of 8 degrees. January, the coldest month, has an average minimum temperature of 49 degrees, and August, the warmest month, has an average maximum temperature of 88.0 degrees.

12. The prevailing winds are from the south or southeast, except during the winter months when high pressure air masses from the north bring northerly winds for short periods of time.

13. Precipitation.- Based on records of the U. S. Weather Bureau station at Galveston, the mean annual precipitation is 41.81 inches. The annual precipitation has ranged from a maximum of 78.39 inches in 1900 to a minimum of 21.40 inches in 1948.

13 14. Tropical storms.- Tropical storms that affect the Texas Gulf coast originate in the Atlantic Ocean near and south of the Cape Verde Islands, in the western Caribbean Sea, and in the Gulf of Mexico. Al- though these storms can occur during month of the year, meteorological conditions most often favor development and movement of the storms inland over the Texas coast during the months of June through October.

15. Tropical storms vary in size from less than 100 miles to over 600 miles in diameter, and in intensity from fresh inds of about 20 miles an hour to winds with velocities exceeding 100 miles hour. In large, severe storms, the area of hurricane velocity winds (75 miles an hour or more) may exceed a width of 100 miles. These storms are accompanied by high tides along the Texas coast ranging up to 16 feet above mean sea level. Both the winds and the resulting high tides and waves have tremendous destructive power and have caused extensive damage and loss of life in the low coastal areas. Whole towns have been inundated and, in some cases, completely destroyed.

16. Storm history..- In the 86-year period, 1879 to 1964, inclusive, 45 hurricanes have affected the Texas coast, on an average of one about every 2 years. The average frequency with which any point on the Texas coast, including the La Marque-Hitchcock area, may be subjected to storms of hurricane intensity is estimated to be once in about 9.2 years.

17. Storm tides. - Tropical storms are accompanied by high winds, high tides, and usually by heavy rainfall. The high winds, while severely damaging in themselves, are not as destructive in the low, coastal areas as the inundation from the high stohn tides and the waves and currents induced by the wind. The tides caused by these storms as they cross the coast are extremely variable, depending on the size, intensity and speed of forward movement of the storm mass, the relative position of the point on the coast with respect to the path of the storm, and the topography of both the onshore and offshore portions of the areas. Severe hurricanes have caused tides of as much as 15 feet above mean sea level in the Galveston Bay area, while lesser moderately large storms usually have caused tides of up to 8 feet above mean sea level. There are very few records of the height of storm tides at the study area; however, records of the storm tides at Galveston are available over a period of about 86 years. Since the study area is only a few miles distant, the Galveston records are considered to be representative of the tide heights in the area. The magnitude of the tides at Galveston exceeding 4 feet above mean sea level and dates of occurrence are given in table A.

14 TABLE A

STORM TIDES AT GALVESTON 1879 THROUGH 1964 Maximum height of tide Date of occurrence at Galveston, in feet (MSL)

September 8, 1900 14.5 August 16, 1915 12.7 September 11, 1961 (Carla) 8.8 August 20, 1886 7.7 September 14, 1919 7.6 August 20, 1942 6.3 June 27, 1957 (Audrey) 6.1 July 25, 1934 6.o September 23, 1941 5.7 October 4, 1949 5.7 October 12, 1886 5.2 July 21, 1909 5.2 September"4, 1933 4.6 September 17, 1963 (Cindy) 4.6 August 13, 1932 4.5

18. Storm tide frequencies.- To define the magnitude of the hurricane flooding problem and to permit assessment of the damages that will occur under existing conditions, a tide-frequency curve was constructed. Data for the curve was based on analysis of storm tides recorded at Galveston, Texas covering an 86-year period from 1879 through 1964. Additionally, a hypothetical tide-frequency curve was constructed from data developed by the U. S. Weather Bureau, based on research of historical records and characteristics of hurricanes that have occurred in the Gulf of Mexico and in the Galveston area. The two curves were correlated and a composite curve was adopted for this investigation. Based on this analysis, a storm tide of 15 feet above mean sea level, with an estimated recurrence interval of once in about 100 years, was selected for design studies. This is in consonance with criteria used for design of the presently authorized project for Texas City and vicinity.

19. Design rainfall frequencies with high tides.- Where low areas are protected from storm tides by leveed enclosures, the effects of heavy rainfaill within the enclosure must be considered. With high exterior tides, drainage systems depending on gravity outflow will be blocked and accumulated rainfall runoff can cause extensive damages inside the enclosure. To permit analysis of this problem, records at Galveston were tabulated to correlate the coincident occurrence of high tides and heavy rainfall. A curve was drawn showing the probability of occurrence of various amounts of rainfall in 24-hour periods coincident with tides of 2 feet or greater. It was found that, coincident with high tides, a rainfall of 9 inches in 24 hours could be expected on an average of

15 once in about 30 years and a 1 -inch rainfall in 24 hours could be expected on an average of once in about 100 years, the same frequency assigned to the design hurricane. Criteria based on these determinations were adopted for analysis of the interior drainage problem coincident with high tides.

20. Desi rainfall frequencies with normal tides.- The improvements for control of upstream flooding on Highland Bayou, Texas, authorized by the Flood Control Act of October 27, 1965, in accordance with a plan contained in House Document No. 168, 89th Congress, 1st session, includes enlargement of Highland you and construction of a diversion channel to contain runoff from a standard project rainfall (21.28 inches in 24 hours). Accordingly, drainage structures for the plans investigated in this study were designed to prevent ponding of interior drainage to damaging elevations from a standard project rainfall during normal tides.

EXTENT AND CHARACTER OF FLOODED AREA

21. Area subject to flooding.- The area subject to flooding by hurricane tidal surge considered by this study totals about 18,000 acres, of which about 3,000 acres are presently occupied by existing development. The developed area includes commercial, residential, and resort properties; streets and bridges; and utilities. About 10,000 acres of the area subject to flooding have elevations of 7 feet or greater. Based on the projected growth rate of the area, it is expected that all of this land will be urbanized and fully developed in future years. In recent months, development activities have been started on some of the low-lying lands by ex- cavating an interconnected system of canals and using the excavated material to raise the adjacent land areas to elevations ranging up to about 8 feet. Most of the residences and summer cottages that have been constructed in such areas have been raised well above the ground level on piles or stilt foundations. The largest development of this type for which plans have been announced is the 3900 acre Flamingo Isles community near the mouth of Basford Bayou. Excavation of some of the canals for this development has been started. Development of resort properties on ground elevations of less than 7 feet is expected to continue; however, due to the relatively short time that such activities have been in progress, it is difficult, at this time, to establish a growth trend and forecast the probable extent of this type of development.

22. The area subject to tidal flooding was investigated in detail and all existing property subject to flood damage was inspected. The value of all physical property existing in 1965 was estimated at $25,692,000. A breakdown of this value by principal classes of property is given in table B. By the year 2065, when the projected growth will have occupied the entire flood plain above 7 feet elevation, the total value of all physical property in the flood plain, based on 1965 price levels, is estimated at $18,,600,000.

16 TABLE B

VALUE OF PHYSICAL PROPERTY IN THE FLOODED AREA OF THE DESIGN HURRICANE FLOOD, EXISTING CONDITIONS (STwY AREA ONLY)

Tyeof propr Value

Residential $17,17I,000 Resort 1,625,000 Commercial 1,776,000 Municipal 1,653,000 Utilities 937,000 Roads,527,000

Total 25,692,000

23. Flood damages.- The flood damage data obtained through the field economic survey formed the basis for estimating the average annual damages. The damages that would result throughout the flood plain of the study area from occurrence of the design hurricane flood under the present stage of development are estimated at $6,375,000. Based on estimates of damages at various elevations of flooding, stage-damage relationships were developed for the areas encompassed by each of the plans investigated. Analyses of storm tide records and characteristics of hurricanes that have occurred in the Gulf of Mexico were used to establish a relationship between peak tide stages and frequency of occurrence, which is expressed as the estimated number of times the various tide stages would be equaled or exceeded in 100 years. Damage-frequency curves were constructed for the areas encompassed by each of the plans by plotting damage-frequency coordinates, which were determined from the mutual stage relationships of the stage-damage curve and the stage-frequency curve. The average annual damages were then computed from the damage-frequency curves. The average annual damages under existing conditions in the study area were computed to be $266,000. Details of these damage estimates are shown in the Project Evaluation appendix.

ECONOMIC DEVELPME T

24. Early development.- Historically, the mainland portion of Gal- veston County, north of Galveston Island, did not share appreciably in the rapid growth and development of the city of Galveston during the 19th and early part of the 20th century. During much of this period, Galveston was the principal seaport and, to a large extent, the financial center of the state. Although Houston, about 50 miles to the north, enjoyed considerable growth during this period, the area between the two cities remained largely undeveloped, except for a few small settlements along the three railroads which were built to connect the cities.- The principal use of the land during this time was for grazing and truck farming. 17 25. Following the devastating hurricane of 1900, Galveston constructed a massive concrete seawall along the Gulf shore and carried out an extensive grade raising program for much of the city, as it then existed. During the first third of the 20th century, Galveston continued to expand until it had occupied virtually all of the protected and raised area on the eastern part of the island, During this period, also, a number of important oil and gas fields were discovered in the area between Galveston and Houston and a small concentration of petroleum refineries had begun to develop around Texas City. By about 1935-40, Galveston had very little remaining area suitable for residential construction and land prices were rising rapidly due to the shortage.

26. Recent development of mainland area.- In 1937, a modern new highway bridge was built across West Bay from Galveston Island to the mainland. In the mid 1950's, easy access was afforded from metropolitan Houston to the area along the Gulf of Mexico and Galveston Bay by the completion of an express highway between Houston and Galveston. Many additional highway improvements have been constructed throughout the mainland area since that time. Starting slowly and increasing rapidly in the years during and following World War II, a marked migration of population to the mainland area has been apparent. The population of Galveston has remained relatively static, while that of the area between Galveston and Houston has grown spectacularly. Texas City, La Marquee, Hitchcock, and Dickinson in Galveston County, Alvin in Brazoria County, and several communities in Harris County have all enjoyed rapid growth since World War II. A substantial industrial development of petroleum refining and petrochemical manufacturing in the Texas City area has accompanied the residential growth. This trend is continuing as evidenced by several recent expansions of existing industrial plants and construction of a large new chemical plant on Chocolate Bayou, a few miles southwest of Hitchcock. Very recently, the National Aeronautics and Space Administration has constructed its Manned Spacecraft Center on Clear Creek in south Harris County, about 15 miles northeast of Hitchcock. Many industrial technological and service installations are being developed in the general vicinity. Although the full impact of this facility cannot be accurately predicted at this time, it is certain that all of the surrounding area, including La Marque and Hitchcock, will be stimulated by the NASA development.

27. Character of physical development.- Although the entire mainland area between Galveston and Houston is developing rapidly in all urban characteristics, the La Marque-Hitchcock area comprises mostly residential and commercial development. The commercial development includes the normal concentration of shops, stores, small business and service establishments that usually accompany residential development. The residences are of comparatively high value and the area presents a general picture of attractive, well-maintained homes, largely owner- occupied.

28. Several of the more recent waterfront subdivisions constructed in the study area are canal type developments with building lot sites

18 adjoining a system of interconnecting canals which afford access for small boats to West and Galveston Bays. Materials excavated from the canals are used to raise the elevation of the lots from 5 to 8 feet above mean sea level0 The homes are constructed on pile foundations with floor elevations raised 8 to 12 feet above ground level. Some of the waterfront homes along West Bay are used as weekend and vacation retreats, however, many are occupied by permanent residents.

EXISTING CORPS OF ENGINEERS PROJECTS

29. Existig flood control po jecto- The Flood Control Act of October 27, 1965 authorized protection from upstream flooding to Hitchcock and La Marque, Texas by improvement of the Highland Bayou cha nel, construction of a diversion dam and a diversion channel following generally along Basford Bayou to Jones y in accordance with a plan contained in House Document No. 168, 89th Coress, 1st sessions Subsequent to submission of the flood control report on Highland Bayou, the Flamigo Isles subdivision has been started along Basford Bayou. It is now planed that during postauthorization pl, the diversion channel will be rerouted to Greens Lake, as shown on plate 2, in lieu of the originally planned route along Basford Byou. rther modification of the diversion channel outlet in connection with hurricane flood protection improvements considered in this report is discussed in paragraph 40.

30. ExistM navigation_ o ect. The only Federal navigation project in the immediate vicinity of the study area is the Gulf Intracoastal Watery, 12 feet deep and 125 feet wide, which extends through West Bay near the mainland shore None of the improvements for hurricane flood protection considered in this report would have any direct effects on the waterwa y. However, the alignment of a position of the levees proposed under two plans considered in this study would follow the general line of a series of spoil mounds located alongte north side of the waterway in Jones Bay. The spoil mounds have been created by deposition of material excavated from the watery o

31A Existing harricane foodpr~ t, cti on o ct a The existing project for Texas City and vicinity, Texas was authoized by the Flood Control Act of July 3, 1958, and provides for c:ostruction of about 18 miles of new and enlarged levees and flood walls, together with related drainage and closure structures, a navigation opening, and pumping plants. The area protected by that project lies immediately north and east of the area studied in this investigation. ostrctIo on the existing project was initiated in 1962 and on June 30, 1965, was 37 percent completed. The current estimated cost for constructing the project (July 1965) is $22,600, ® Funds presently available will permit all design work to be substantially completed,, and will provide for overall project completion of about 60 percent on June 3Q, 1966. Work on constructing one pumping station on the south side of La rque.M the construction

19 of the levee from this pump station to the westerly terminus of the project, previously scheduled for 1964-1965, has been deferred pending the results of this study. In addition to these two deferred items, work remaining to complete the authorized project, presently scheduled for construction in 1967 and 1968, is as follows: (a) second stage construction of levee across Moses Levee, (b) second, stage construction of levee in Galveston Bay, (c) construction of levee from the end of the Industrial Barge Canal to the Texas City pumping station, and (d) connection of the levee with Interstate Highway 45 in the vicinity of the Texas City Terminal Railway 'Company railroad overpass.

PROJECT FORMULATION

32. Plans investigated.- Five general plans for protecting the La Marque-Hitchcock vicinity from damages caused by tidal flooding were studied in some detail. All plans considered the elimination of portions of the authorized hurricane flood protection project for Texas City and vicinity. Completion of this study prior to completion of the authorized hurricane flood protection project is necessary to avoid construction of items that would not be functional upon completion of a modified project. In view of the urgency of this study, the study concerns only that area immediately adjacent to the authorized hurricane flood protection project. It is recognized that, in the future, additional areas in the general vicinity of the coast will develop and require protection. However, a study now in progress will consider unitized hurricane flood protection for the entire Texas Gulf coast. Any such additional areas of development will be considered for protection in this comprehensive Texas coast hurricane flood protection study. The five general plans considered in this study are shown on plate 3 and described as follows:

a. Plan A - Under this plan, the proposed improvements would join the authorized project just south of the junction of Interstate Highway 45 and the Texas City Terminal Railway track. From that point the alignment would extend southward across Highland Bayou, Texas High- way 6, and the G.C. & S0F. railroad; westward along the railroad; and southwestward below Hitchcock to high ground. The plan would include a pumping plant, a bridge and ramp at Highway 6, a bridge and closure structure at the G.C. & S.F. railroad, gated drainage structures and a navigation gate at Highland Bayou, and gated drainage structures at the crossing of the Basford Bayou diversion channel rerouted to Greens Lake as described in paragraph 29.

b. Plan A - alternate - This plan would follow an alignment identical to plan A. The plan, however, would include modification of the previously recommended flood control plan for Highland Bayou to substitute diversion of the upper Highland Bayou runoff through an alternate channel to Krankawa Bayou in lieu of the Basford Bayou diversion channel rerouted to Greens Lake. Thus, the need for gated drainage structures

20 at the rerouted diversion channel would be eliminated, but a much more extensive diversion dam would be required northwest of Hitchcock to prevent storm tides from flowing through the alternate diversion channel and overflowing into lower areas north of Hitchcock.

c. Plan B - Under plan B, the proposed improvements would join the authorized project at the same location as plan A. From that point the alignment would extend southward into the marsh area and westward to high ground south of Hitchcock. The drainage and navigation structures at Highland Bayou, the drainage structure at the rerouted Basford Bayou diversion channel, the bridges and ramp for Texas Highway 6, and the bridge and closure structure for the G.C. & S.F. railroad would be the same as under plan A. However, a pumping plant at Highland Bayou would not be required.

d. Plan C - Plan C would join the authorized project at the same location as plan A. From that point the alignment would extend southeastward along Interstate Highway 45 past its junction with Texas Highway 6, then southward into Jones Bay to the north side of the Gulf Intracoastal Waterway and westward through the bay and across land to high ground south of Hitchcock. his plan would( not require a pumping plant, but would require gated drainage and navigation structures in Jones Bay, a closure structure at Texas Highway 6, and a bridge and closure structure at the G.C. & S.F. railroad. The lower portion of the proposed revised diversion channel to Greens Lake would be modified to an alignment along the inside of the hurricane flood protection levee to Jones Bay.

e. Plan D - Plan D would join the authorized project at the Texas City pumping station near the junction of Texas Highway Loop 197 and the Texas City Terminal Railway. From this point, the alignment would extend southwestward to the Galveston, Houston and Henderson Rail- road, southeastward along the railroad, then turning southwestward to cross the railroad and Interstate Highway 45 and to follow the same alignment as plan C to high ground south of Hitchcock.

33. Subsequent to the formulation of the above plans, a local developer announced plans for development of a very large subdivision named Flamingo Isles near the mouth of Basford Bayou. Construction activities are under way which will include the dredging of a system of interconnecting canals and raising the adjoing lots to an elevation of 8 feet above mean sea level. The developers are planning to build homes, churches, schools, and commercial buildings on the raised lots. Since this development would preclude the acquisition of necessary rights- of-way and ponding easements in that area without incurring excessive costs, no further study was made on plan B. The location of Flamingo Isles is shown on plates 2 and 3.

34. Plan D was developed and investigated to determine whether cost savings could be attained by eliminating that portion of the authorized Texas City hurricane flood protection project from its intersection

86-965 0-67-3 21 with plan Dto its southwestern termius use:nly it was found that local interests had co dtted funds to acquire rigts-of-way in the area between Texas Highay Iop 197 and Interstate High ay 45. In addition, ramps that were designed to tie into the authorized levee at Interstate Highway 45 are being constructed by the Texas Highway Depart- ment. Since most of these costs could not be recovered if the levee were rerouted, plan D was eliminated from consideration

35. Cormarison of las - For economic comparison of the plans investigated on a common scale, designs and cost estimates were made for improvements that would prevent flood damages from: (a) maximum wave runup of a 15-foot tide under design hurricane conditions, (b) interior drainage runoff from a 100-year rainfall coincident with high tides and (c) interior drainage runoff from a standard project rainfall with noel or low tides. The economic comparison of the plans investigated are summarized as follows:

Recess Benefits Annual Annual benefits to costs benefits costs over costs ratio

Plan A $376,000 $474,000 0.8

Plan A-alternate 376,000 496,000 0.8

Plan C 866,000 597,000 $269,000 1.4

36. The authorized flood control project forI igh and Bayou described in House Document No. 168, 89th Congress, 1st Session, provides for protection from upstream flooding to the La Marque-Hitchcock area by a channel for diverting all runoff from above Highland Bayou stream mile 8.65 through Basford Bayou to West Bay, and by improving Highland Bayou as necessary below the point of diversion. An alternate plan investigated during that study provided for diverting all runoff from above Highland Bayou stream mile 9.50 through Karakaw Bayou and Karankava Lake to West Bay and improving Highland Bayou as necessary below the point of diversion. For control of stream floods, the plan as now authorized was found to be the best pl, as well as being the most economical and requiring the least disruption and relocation of existing improements However, the investigated diversion through Krankawa Bayou and Lake would follow a route from Highland Byou to Karaawa Bayou through natural ground higher than 15 feet elevation T.hus, a hurricane surge of 15 feet above mean sea level would not overflow the banks of the diversion channel and would eliminate the need for a gated structure across the channel that could be closed to exclude the hurricane surge Accordingly, during this investigation plan A-alternate was developed and investigated to determine whether a more favorable combined plan of upstream flood protection and hurricane flood protection could be ataind by Incorprating a hurricane flood protection plan with the Karat aid diversion plan in lieu of the authorized flood control :apro emets It was found that the reasons that dictated selection of th: Basford B d.fversion plan for control of stream flooding were equally valid for a plan affording Protection from both stream flooding and hurricane tidal flooding.

37. Selectiono fplan.- Of the five plans, A, A-alternate, B, C, and D, originally developed for economic and engineering investigation in this study, plans B and D were eliminated from consideration because of the development of physical conditions that render construe- tion impracticable. Of the three remaining plans, only plan C offered a favorable benefits to cost ratio and, accordingly, was selected as the plan of improvement. Tests to determine the effects of varying physical features of the plan to afford greater or lesser degrees of protection were not made because the planned work would be an extension of an existing project. The selected plan would afford the same degree of protection from tidal flooding to portions of the cities of La Marque and Hitchcock and adjacent subdivisions as the authorized project will afford to Texas City and the remaining portion of La Marque. The plan would provide simply for modification and extension of the existing project and should be consistent with that project throughout.

PLAN OF IMPROVEMENT

38. Plan of im rovement. The plan of improvement provides for construction of about 11.4 miles of earthen levee with related drainage and closure structures and a gated navigation and tidal control structure in Jones Bay. The proposed levee would join the authorized Texas City hurricane flood protection project near its junction with Interstate Highway 45 and follow the route of plan C described in paragraph 32 and shown on plate 2. The authorized La Marque pumping plant and adjoining levee extending northwestward on the westerly side of Interstate High- way 45 would be eliminated from the Federal project and would not be constructed with Federal funds. Design of all features proposed under the plan would be consistent and in accordance with criteria developed for preconstruction planning of the presently authorized project.

39. The proposed levee would be trapezoidal in cross section with a 24-foot crown width at top elevations of 21 feet above mean sea level datum between miles 0 and 10.0, from 21 feet to 16 feet between miles 10.0 and 11.2, and from 16 feet to 15 feet between miles 11.2 and 11.4. These crown elevations are those required to prevent overtopping by the significant waves during the passage of a design storm. The segments of the levee on land areas would have turfed side slopes, 1 vertical on 6 horizontal on the exterior side, and 1 vertical on 3 horizontal on the interior side. The segment in Jones Bay would have 1 vertical on 10 horizontal side slopes, both sides, with riprap protection from 5.0 feet below mean sea level to 5.0 feet above, and turfed side slopes above the riprap. The crown on all segments would be surfaced with flexible bituminous pavement. Information pertaining to the selection of the design grade and cross section for each levee reach is contained in paragraphs 27 through 33 of appendix I. Typical sections of the design levee are shown in appendix III.

40. Sections of the levee located on land would be constructed of materials excavated from borrow areas adjacent to the levee alignment, and the resulting borrow ditches would be used for collecting and carrying interior runoff to the Jones Bay ponding area. The levee section in 23 Jones Bay would be constructed from materials excavated and placed with hydraulic dredging equipment. The alignment of the proposed revised diversion channel to Greens Lake of the Highland Bayou flood control project would be modified to follow along the borrow area on the inside of the hurvcane flood protection levee to Jones Bay. The borrow ditch in this reach would be sized to provide for discharge capacity required to meet design criteria of the flood control project. About 538 acres would be required for rights-of-way and about 6,600 acres of water and low land areas would be used for temporary storage of runoff from interior rainfall during storm periods when gravity drainage would be blocked by exterior tides.

41. Closure structures would be provided where the proposed levee alignment crosses Texas Highway 6 and the Gulf, Colorado, and Santa Fe Railroad. Alteration of two 30-inch water lines and 3 overhead pole lines (1 power, 2 telephone) would be required. One new railroad bridge would be constructed across a borrow ditch. A tide control structure with a 56-foot wide gated navigation opening would be constructed in Jones Bay to provide navigation access to Highland Bayou and the canal subdivisions that would be inclosed by the levee. The developer of Flamingo Isles has dredged two access channels to the Gulf Intracoastal Waterway. Oil exploration companies have dredged flotation channels in Jones Bay for the movement of barge drilling equipment. Accordingly, it is necessary to preserve navigation access to the land and bay area inside of the proposed levee, and to Highland Bayou. In order not to obstruct future navigation developments in the area, and to provide adequate opening for tidal exchange, the dimensions of the gated structure were established at 56 feet horizontal with the sill elevation at the same depth as the nearby Gulf Intracoastal Waterway at minus 13 feet mean sea level datum (minus 12 feet, mean low tide datum). The vertical clearance of the gate is the same as that for the tidal control and navigation structure in Moses Lake of the authorized project, which was established at 52 feet mean sea level datum in accordance with standards prescribed for tributary channels of the Gulf Intracoastal Waterway. Six 3-foot high and 5-foot wide gated drainage culverts would be placed through the levee in Jones Bay located to provide circulation in the inclosed bay area. The combination of the tidal control and navigation structure and the six gated drainage structures would provide adequate openings for the interior drainage of the leveed area. Typical details of the various structures are shown in appendix III. A channel suitable for the discharge of flows through the tidal control and naviation structure would extend from inside the levee system to the Gulf Intracoastal Waterway. Connecting access channels would be dredged from the tidal exchange channel to any existing locally dredged channels that would be crossed by the proposed levee. Dimensions of the access channels would be commensurate with those of the existing private channels, or of lesser size if not required by existing or foreseeable traffic. Inasmuch as there is no Federal navigation project in Jones Bay or Highland Bayou, Federal maintenance of the tidal exchange channel and the access channels would not be appropriate. Any maintenance of the tidal exchange channel necessary for hurricane flood control project purposes would be performed as part of the local operation and maintenance of the entire project. Any maintenance or improvement of the channels required for navigation to the private developments within the enclosed area would be performed by the Department of the Army permitees for the existing locally constructed channels. 24 42. The proposed levee and appurtenant structures would be designed to prevent flood damage from: (a) a surge level of 15 feet above mean sea level and the storm waves associated with hurricane surges, (b) interior drainage runoff from a 100-year rainfall coincident with high tides, and (c) interior drainage runoff from a standard project rainfall of 21.3 inches in a 24-hour period with normal or low tides.

ECONOMIC EVALUATION OF PROJECT

43. General.- The economic evaluation of the recommended plan of improvement for hurricane flood protection to the study area included comparisons of estimated benefits and costs to insure that the best plan had been developed and construction of the proposed improvements was fully justified from an economic standpoint. The various factors entering into these determinations are discussed in paragraphs 32 through 37.

44. Estimates 'offirst cost.- Detailed estimates of first costs for constructing the proposed plan of improvement for affording hurricane flood protection to the La Margue-Hitchcock area are summarized in the following table C. The estimates are based on December 1965 price levels.

TABLE C ESTIMATES OF FIRST COSTS FOR PLAN OF IMPROVEMENT (PLAN C)

Item Cost Lands and damages $ 510,000 Relocations 206,000 Channels 98,000 Seawalls 14,636,000 Engineering and design 1,350,000 Supervision and administration 1,420,000 Subtotal, construction first costs 18,220,000 Less credit for eliminated portion of authorized project -2, 520,000 Total estimated first cost 1/ 15,700,000 l/ Additional cost to authorized project by modification to include plan C.

45. Estimates of annual charges.- For economic analysis of the proposed modification on an incremental basis, detailed estimates of the additional investments and annual charges for the plan of improvement have been computed and are summarized in table D. An interest rate of 3.125 percent and a period of 100 years for amortization of the investment were used for computation of the annual charges.

25 ESTIMATES OF ADDITIONAL I S S CHARGES FOR PLAN OF IPOEET(LNC)

Item Tt al

Investment: Federal first cost (70% of total) 1990 Interest during construction _686 800 Federal investment Ell, 7 ,

Non-Federal first cost (30% o total) 4710,9000 Interest during construction 294 400 Non-Federal investment

Total investment 8,000 Annulcharge

Federal Interest ndamortization Maintenance and operation _Non_

Subtotal, Federal

Non-Federal Interest and amortization Maintenance and operation 509000

Subtotal, non-Fed ra:< 214, 000

TOta_1an nu al res: 5979000

6. Benefits.- The incremental benefits which would be drid (from the construction of the plan improvement would consist of prevention of tidal flood damages existing property and to additional future development within the area subject to tidal flooding that an be expected to occur within a period of 100 years in the absence of a hri ane flood protection project

47. Prevention of d Ges As iussed in paragraph 23 the average annual damages to existing property from tidal flooding in the area encompassed by plan C are estimated at $266,000 These damages include the primary physical damages to property from flood inundation and waves. All such damages from storms as large as the design hurricane would be prevented by the improvements proposed der plan and are credited as benefits for the pl0 Secondary damages such as loss of production, loss of life, loss of w aes, andadverse effects to public health, security and national defense were not evaluated a no beneIts have been included for prevention of such damages,

26 18.The e sti tedbenefits from the prevention of damages would be increase d by the prevention of damages to additional properties that will be constructed in the b ren:e of the project. he economic base study included in appendix of this report indicates that a future aver-e annual art rate of about 1.6 percent can be expected within the study area. In addition, as discussed in paragraph 15 of appendix II, a very large residential development nown as FlamingoIsles is now under construction. The niti l unit of this development is firmly committed for a development expenditure of about 5,000,000, which is expected to engender construction of physical property with a total value of about $26,000,000 by 1975. Based on these factors, estimates of da es prevented to future development over a 100-ye period have been made and reduced to avereaual equivalent benefits bycood interest procedures.

49. Residual aes.- e improvements proposed under plan C would afford full protection from storms as lrge as the design hurricane, which has an epc ted recurrence interval of about 100 years. Under the plan some remaining, or residue, damages would still occur with the proposed improvements in operation. he residual damages would be eprienced from storms larger than the design hurricane and from related rainfall that would be poded during high tidal surges. Although the proposed improvements would be damaged by such storms, it is extremely unlikely that the protection would be breached and damages to property in the protected area would be materially reduced by the improvements. Residual damages have been excluded from the benefits estimated for the improvements.

50. S' rof benefits.- e total annual benefits that would accrue from the improvements proposed in this report, including the benefits attributable to the future growth and development are estimated at $866,000, based on December 1965 prices, and are summarized as follows:

ao Hurricane flood damages prevented to existing property $226,000

b. Hurricane flood damages prevented to future developments600{l)

Total average nu benefits $866,000

(1) Average a ual equivalent benefits

51. Coinarison of benefits and costs.- e estimated average annual benefits, ual charges and ratio of benefits to charges for the hurricane flood protection plan of improvement, are as follows:

Average annual benefits ------$866,000

Annual charges ------597,000

Ratio of benefits to charges------104

27 APPORTIONMENT OF COSTS

52. Apportionment of costs among interests.- The existing project for hurricane flood protection for Texas City and vicinity, Texas, was authorized by the Flood Control Act of July 3, 1958. Congress, in authorizing the project, made specific provisions for local cooperation in lieu of the local cooperation recommended by the Chief of Engineers in the report contained in House Document No. 347, 85th Congress, atses- sion. The improvements considered herein would modify and extend the project to afford protection to an additional adjacent area. The provisions of local cooperation should be in consonance with those for the existing project. Accordingly, under these provisions, local interests would be required to contribute 30 percent of the first cost of the project including the cost of lands, easements, and rights-of-way. Seventy percent of the first cost of the project and all preauthorization survey costs would be'borne by the Federal government. All costs of maintenance and operation of the works after completion would be borne by local interests. The estimated total first cost of the modification proposed in the plan of improvement is $18,220,000, including $12,750,000 Federal first cost and $5,466,000 non-Federal first cost. Construction of the proposed modification would eliminate the necessity for constructing a portion of the authorized project with an estimated first cost of $2,520,000. Accordingly, construction of the modification would require a net increase of $15,700,000 in the first cost of the authorized project. Apportionment of the total estimated additional first cost and the annual maintenance cost is. shown in table E.

TABLE E

APPORTIONMENT OF ADDITIONAL FIRST. COST AND ANNUAL MAINTENANCE COST FOR PLAN OF IROVEMENT (PLAN C)

Item : Federal Non-Federal Total

First cost Construction $10,990,000 $4,004,000 $14,994,000 Lands None 500,000 500,000 Relocations None 206,000 2o6,000

Total first cost 10,990,000 4,710,000 15,700,000(1)

Annual cost of maintenance and operation None 50,000 50,000

(1) Additional cost to authorized project by modification to include plan C. Apportioned 70 percent to Federal and 30 percent to non-Federal interests. Does not include $2,520,000 estimated cost of work eliminated from authorized project.

28 LOCAL COOPERATION

53. Proposed local cooperation.- The local cooperation requirements for the proposed improvements are those generally specified by law for such projects. Although not identical in language, the requirements, in essence, are the same as those specified by the authorizing legislation for the existing project for Texas City and vicinity, Texas. Sub- sequent to authorization of the existing project in the Flood Control Act of July 3, 1958, certain administrative decisions were made by the Chief of Engineers to clarify application of the local cooperation requirements. These decisions pertained mostly to the mechanics of acquiring real estate and accomplishing relocations. Subsequent recommendations for construction of hurricane flood protection projects at other local- ities have been made subject to local cooperation requirements as expressed in the following subparagraphs. Accordingly, it is proposed that local interests shall. be required to participate in modification of the project as follows.

a. Provide, without cost to the United States, all lands, easements and rights-of-way including all borrow areas, and the relocation of buildings, pipelines, and utilities necessary for the construction of the additional work, at costs presently estimated at $706,000;

b. Bear 30 percent of the additional first cost, to consist of the fair value of items listed in a above and a cash contribution presently estimated at $4,004,000 (exclusive of $756,000 required as a contribution towards the cost of the authorized project), to be paid either in a lump sum prior to initiation of construction or in installments prior to start of pertinent work items, the final apportionment of costs to be made after actual costs and values have been determined;

c. Hold and save the United States free from any claims for damages due to the construction work;

d. Maintain and operate all works after completion in accordance with regulations prescribed by the Secretary of the Army; and

e. Prevent any permanent reduction in the ponding volume unless such is offset promptly by pumping capacity or other means at no cost to the United States.

54. All lands, easements and rights-of-way, including necessary relocations of buildings, pipelines and utilities, will be provided by the local interests without cost to the United States and the fair value thereof will be credited toward the local cooperation. Local interests for the existing project are represented by the Commissioners Court of Galveston County, Texas. Officials of this agency have offered to meet the requirements of local cooperation for the hurricane protection improvements proposed in this report. It is considered that the Commis- sioners Court of Galveston County is fully qualified and capable of complying with the requirements of local cooperation listed above.

29 COORDINATION WITH OTHER AGENCIES

55. Initiation of studies.- Copies of the notice of public hearing, held in Hitchcock, Texas, on January 8, 1963 were sent to all known Federal, State and local agencies that were believed to have a possible interest in hurricane flood protection for the study area.

56. The Bureau of Sport Fisheries and Wildlife of the United States Fish and Wildlife Service and the Texas Parks and Wildlife Department were advised by letters of the plans being investigated in this study and the views and comments of those agencies were requested. Subsequent to completion of a draft of the proposed report, copies were sent to the offices of the Federal agencies listed below for field level review and comment. Replies from these agencies are included in appendix IV and summarized in paragraphs 61 through 64.

a. Regional Director, Region 2, Bureau of Sport Fisheries and Wildlife, Fish and Wildlife Service, U. S. Department of the Interior, Albuquerque, New Mexico.

b. Regional Program Director, Water Supply and Pollution Con- trol, Public Health Service Region VII, U. S. Department of Health, Education and Welfare, Dallas, Texas.

c. State Conservationist, Soil Conservation Service, U. S. Department of Agriculture, Temple, Texas.

d. Area Director, Area IV, Mineral Resource Office, Bureau of Mines, U. S. Department of the Interior, Bartlesville, Oklahoma.

57. In a report dated October 20, 1964, the Acting Regional Direc- tor, Region 3, Bureau of Sport Fisheries and Wildlife, U. S. Fish and Wildlife Service, analysed the effects on fish and wildlife of the plan of improvement presented herein. The report stated that the project is not expected to affect wildlife resources and will have no appreciable effect upon fresh-water fish habitat in the bayous of the area. The report further stated, however, that the effect upon the Jones Bay estuary is expected to be profound and extremely detrimental. Jones Bay was described as a shallow, brackish arm of West Bay and an important breeding, feeding, and nursery area for fish and shellfish, which were listed as spotted seatrout, red drum, flounders, black drum, blue crabs, menhaden, and shrimp. The report stated that Jones Bay contributes significantly to the sport and commercial fishery of the Galveston Bay estuarine system and associated offshore waters and that is is fished heavily by sportsmen. Without the proposed hurricane flood protection project, it was estimated that sport fishing would amount to about 32,000 man-days annually and that the bay would contribute about one million pounds annually to the commercial fishery harvest.

30 58. In analysis of the proposed hurricane flood protection project, the Acting Regional Director stated that the major portion of Jones Bay will be effectively isolated from the remainder of West Bay by the levee. This would result in the loss of its sport and commercial fishery and its contribution as nursery breeding and foraging grounds for West Bay. The report expressed opinions to the effect that: (a) circulation in that portion of Jones Bay lying east of the levee will be curtailed, (b) expected increases in agricultural, industrial and domestic pollution entering the bay through its contributing bayous will accumulate in the enclosed bay, and (c) although water-exchange openings will be provided in the levee, it is highly unlikely that a sufficient number of openings can be provided for adequate circulation of water and nutrients. To avoid loss of the valuable fishery resources of Jones Bay, the Acting Regional Director recommended that the levee be placed on shore, with openings at the mouths of all major streams to allow for small boat navigation, egress of nutrients, and diffusion of pollutants.

59. The report and recommendation of the Bureau of Sport Fisheries and Wildlife was carefully considered. It was concluded that it would not be practicable to place the levees entirely on shore because construction costs of the project would be raised excessively. Complete function- inof the proposed hurricane flood protection project requires adequate interior drainage of the enclosed area during the high tide conditions associated with tropical storms. Most such storms are accompanied by heavy rainfall and interior runoff cannot be allowed to accumulate to seriously damaging levels inside of the enclosure. In most cases, the problem is handled by temporary storage, or ponding, in the lowest areas where little damage results, and by pumping out of the enclosure any excess that cannot be tolerated by means of the temporary storage. The large costs of constructing and operating pumping facilities normally dictate minimum use -of this method. In the plan of improvement presented herewith, interior drainage would be handled entirely by temporary storage in ponding areas, with about one-half of the planned storage capacity being located in the enclosed portion of Jones Bay. A somewhat greater amount of storage capacity would be lost by placing the enclosing levees entirely on land, the exact amount being dependent upon the levee locations. Without pumping facilities, this would result in ponding to elevations where large damages would be incurred. The installation of sufficient pumps to compensate for the diminished ponding capacity would add substantially to the project costs, probably to the point that the project would be unfavorable from an economic standpoint.

60. The normal range of tide in Jones Bay is about 1 foot, with the tidal inflow and outflow to the area that would be enclosed by the levee being on the order of 2,000 acre-feet of water during a normal diurnal tidal cycle. Computations show that, with the average head differential to be expected on opposite sides of the levee during a normal tidal cycle, the addition of six 3-foot by 5-foot concrete culverts would augment flow through the 56-foot wide navigation opening sufficiently to accommodate about 80 percent of the total volume of tidal

31 flow during the tidal cycle. Accordnly, to minimize the detrimental effects pointed out by the Bureau of Sport Fisheries and Wildlife, six 3-foot by 5-foot gated concrete culverts under the levee in Jones Bay have been included the plan. To retain approximately the same circulation pattern, the culverts are separated into two groups of three as shown on plate 2. Relative to the concern expressed for increased pollutants in the future, it is pointed out that state and local agencies having jurisdiction in this field are actively investigating the problem in the entire Galveston Bay area. It is likely that their investigation will lead to more stringent controls designed to curtail pollution at its source. There appears to be no feasible means of providing for this purpose in a hurricane flood protection project.

61. U. S. Fish and Wildlife Service.- The Assistant Southwest Regional Director, Cooperative Services, U. S. Fish and Wildlife Service, Bureau of Sport Fisheries and Wildlife, in a letter dated September 13, 1965 advised that most of the fish losses envisioned in the Bureau's report dated October 20, 1964 will be offset by including the six gated concrete culverts mentioned in paragraph 60.

62. U. S. Public Health Service.- The Regional Progran Director, Water Supply and Pollution Control, U. S. Public Health Service, Region VII, in a letter dated September 13, 1965 advises that, in general, the project will benefit public health in the area generally by reducing flooding and hazards during times of hurricanes. Also, the channel improvements on Highland Bayou should promote drainage of low areas eliminating mosquito breeding locations. However, the restriction of flow to and from Jones Bay produced by the construction of the levee proposed in plan C may result in a highly unsatisfactory water quality condition in the area behind the levee. Highland Bayou receives the treated effluent from several municipal waste treatment plants. Jones Bay is located in a part of West Bay classified by the Texas State Department of Health as an insanitary area, thus, restricting the harvesting of oysters.

63. U. S. Soil Conservation Service.- The State Conservationist (Texas) in a letter dated September 3, 1965 advises that the Soil Con- servation Service has no projects planned in the area involved, and has no comments to make concerg the proposed project.

64. U. S. Bureau of Mines.- The Area Director, Area IV, Mineral Resources Office in a letter dated September 1, 1965 advises that the Bureau favors the proposed works of improvement which will provide protection to petroleum refineries, petrochemical plants, a tin smelter and other mineral industry plants in the area.

32 DISCUSSION

65. Discussion.- This report comprises the results of an investigation to determine the advisability of modifying the existing hurricane flood protection project for Texas City and vicinity, Texas to provide for extension of the projects to afford protection to the unprotected portion of La Marque and the adjacent city of Hitchcock. The cities of Texas City, La Marque, and Hitchcock, Galveston County, Texas, adjoin each other along the westerly shore of Galveston Bay about 12 miles from the Gulf of Mexico. Texas City and a portion of La Marque will be protected when the authorized Texas City hurricane flood protection project is completed. The unprotected portion of La Marque and Hitchcock comprise about 28 square miles of land varying in elevation from mean sea level to 15 feet. About one-third of the study area is presently occupied by residential and commercial development and it is expected that the entire area lying above 7 feet elevation will be developed by the year 2065. Within the past 2 to 3 years, substantial developments of residential and summer cottages have been started in the low areas lying below 7 feet elevation. Although it appears that such development will increase very rapidly in the near future, the short historical period of development makes it difficult to establish a specific growth trend and forecast of the ultimate extent of this type of development. For purposes of this study, it has been estimated that the future development will at least include that in the low-lying area which has been started at this time and is firmly committed for completion within the next 10 years. The remaining benefits from future growth and development have been estimated on the basis of a conservative average annual growth rate of 1.6 percent, as indicated in the economic base study. The occurrence of a design hurricane flood, which might be expected to occur once in about 100 years, would cause damages in the study area of about $6,375,000 under existing conditions. Average annual damages from hurricane flooding under existing conditions are estimated at $266,000.

66. The Com issioners Cort of Galveston County, Texas, is the local agency that has assumed responsibility for providing local cooperation for the existing hurricane flood protection project for Texas City and vicinity, Texas. At the public hearing held in Hitchcock, Texas on January 8, 1963, in connection with this study, the Commissioners Court requested that the project be extended to afford protection to Hitchcock and the western portion of La Mrque. They proposed an alignment that would join the authorized project near Texas Highway mop 197; but, subsequent to the hearing, modified their request by proposing an alignment that would join the authorized project at the La Marque pump station near Interstate Highway 45.

67. Various plans, to provide hurricane flood protection to the study area, were developed and investigated, as shown on plate 3 of this report. The most practicable plan of improvement was found to be plan C, which would provide for enclosure of the study area by an earth levee,

33 with gated navigation and drainage openings in Jones Bay and closure structures at highway and railroad crossings. The alignment for the recommended plan is shown on plate 2.

68. The improvements proposed under plan C would join the existing project for Texas City and vicinity on the westerly side of Interstate Highway 45, near La Marque, and extend southward and westward to terminate on high ground south of Hitchcock . With protection along this route, the need for the portion of the existing project extending northwestward from the proposed junction along Interstate Highway 45 to high ground west of La Marque would be eliminated. Under the modified plan, interior drainage would be ponded in Jones Bay and adjacent low areas ' the need for the La Marque pump station and several drainage structures, planned as part of the existing project, would also be eliminated. Based on current approved cost estimates for the existing project, features with a total estimated cost of $2,520,000 would be eliminated from the existing project by the proposed modification.

69. Based on December 1965 prices, the total first cost of the proposed improvements for extension of the Texas City hurricane flood protection project is estimated at $18,220,000 including $12,750,000 Federal first cost and $5,466,000 non-Federal first cost. The net additional cost of the modified project, with deduction of the cost of features of the existing project that would be eliminated by the proposed extension is estimated at $15,700,000, of which $10,990,000 would be Federal cost and $4,710,000 would be non-Federal, in accordance with the apportionment of costs described in paragraph 52. The non-Federal share of the cost for the features eliminated from the authorized project, estimated at $756,000, would be required for application towards the cost of constructing the proposed modification. The total annual charges for the proposed extension are estimated at $597,000. The proposed improvements would prevent practically all flood damages from storms as large as the design hurricane, which has an estimated recurrence interval of about 100 years. Total average annual benefits from the proposed improvements are estimated at $866,000. The benefits to costs ratio is estimated at 1.4.

70. Present construction schedules call for the existing project to be completed in 1968, with the portions that would be eliminated being among the last items of construction. With completion of the remainder of the existing project, all of Texas City, including the industrial areas, and a considerable part of La Marque on the northwest side, will have protection from hurricane flooding, virtually to design hurricane conditions. Until the existing project westward of Interstate Highway 45 or the modification proposed herein is constructed, portions of the residential areas of La Marque on the west and south sides of the city will be without protection. It is estimated that hurricane "Carla" in September 1961 produced surge heights from 10 feet to 13 feet above mean sea level in the study area and caused approximately $2,350,000 in flood damages.

71. It has been assumed that the modification proposed herein will be authorized and constructed within reasonable time limits. If this is true, construction of the portions of the existing project that would no longer be needed would serve only to afford protection to a relatively small area for a short period of time, probably a maximum of from 5 to 7 years. At the present time hurricane surges of 7 feet or less would 34 produce only minor damages the area. Thus, in view of the substantial amount of savings to be achieved, it seems reasonable to accept a small degree of risk for a few years' time. Accordingly, it is proposed that the features of the existing project westward of Interstate Highway 45 would not be constructed with Federal funds until it became evident that the modification proposed herein cannot be constructed.

72. The Galveston County Commissioners Court, local sponsors for both the existing project and the proposed modification, does not agree that construction of the levee westward of Interstate Highway 45 should be delayed, pending construction of the improvements proposed herein. The Commissioners Court has repeatedly expressed its desire to have the existing project completed as planned at the earliest possible date. They do agree that construction of the La Marque pump station could be deferred without serious risk. Numerous local problems have been considered by the Commissioners Court in arriving at its decision that the levee structure westward of Interstate Highway 45 should be constructed without delay. Among the more important points expressed are the following:

a. Three bond issues have been passed to provide local funds for the project as now authorized, and a substantial delay in completing a portion of the project would, in effect, be breaking faith with the voters that approved the bonds.

b. Local cooperation for the improvements proposed herein can be provided only with another bond issue and there is no assurance that a subsequent bond issue would be promptly approved by the voters in a later election. Thus, the unprotected area might be exposed several years longer than necessary.

c. Conceding that only a major hurricane would produce appreciable damages in the unprotected area under existing conditions, there can be no assurance that such a storm will not be experienced. If so, the resulting damages could exceed the cost of providing at least temporary protection for the area.

73. After weighing all of the problems, the Galveston County Com- missioners Court has furnished assurance that it will assume responsibility for local cooperation for the improvements proposed herein, as described in paragraph 53. This agreement was given with the understanding that the portions of the authorized project westward of Interstate Highway 45 would not be constructed with Federal funds, if the improvements proposed herein are subsequently authorized and constructed in accordance with the recommendations. However, to prevent even temporary prolongation of exposure of the area that would be protected by the west leg of the authorized project, the Commissioners Court has stated its intention to construct at least a temporary levee, using county funds entirely to do so. Further, they state that the levee and such drainage structures as are absolutely essential, will be built on the same alignment and to the same elevation as planned under the existing project and be completed by 1968. If this is done, they will expect that, if for any reason the

35 modifications proposed herein cannot be subsequently constructed, the project as now authorized, including the pump station, will be completed, and they will be credited with the fair value of useful work performed on local cooperation requirements for the existing project. To the extent that any such work performed could be utilized in the completed project, this seems reasonable.

74. It is recognized that financing of the local share of the cost of modifications proposed herein will present considerable difficulty to the local interests. It is possible that local bond issues for this purpose may fail to be approved by the voters. As discussed above, some areas that are scheduled for protection by 1968 under the existing project will either be without protection, or afforded a lesser degree of protection by the county constructed levee, until the improvements recommended herein have been completed. It is believed imperative that this should not be an excessively long period. Accordingly, it is proposed that a limiting period of 3 years shall be given the local interests to meet local cooperation requirements for the proposed modifications, this period to begin with the date of the authorizing legislation. If the local cooperation is not provided within this limiting period, or if the responsible local government officials formally give notice that the local cooperation cannot be provided, authority for the recommended modifications should be considered to have expired. The project should then automatically revert to its presently authorized status, and be completed as rapidly as possible.

75. Additional information called for by Senate Resolution 148, 85th Congress, adopted January 28, 1958, is contained in an attachment to this report.

CONCLUSIONS

76. Conclusions.- Based upon findings of this investigation, it is concluded that:

a. A serious flood problem exists in portions of La Marque and Hitchcock, Texas where commercial and residential development are subject to damages from tidal surges that accompany tropical storms. Although adjacent to Texas City, these areas will not be protected by the presently authorized hurricane flood protection project for Texas City and vicinity, Texas, which is now under construction.

b. Construction of the protective levee and appurtenant structures as described in the plan of improvement would prevent all tidal flood damages from storms as large as the design hurricane, which has an expected recurrence interval of about 100 years. Damages from larger storms would be materially reduced. This would provide the same degree of protection to the additional area as that afforded to Texas City and vicinity by the presently authorized hurricane flood protection project.

36 -PCOMI ATIONS

77. Recommendations.- Accordingly, it is recommended that the existing project for hurricane flood protection for Texas City and vicinity, Texas, be modified to extend southward and westward and afford the same degree of protection to adjacent areas in the western part of La Marque and Hitchcock, Texas, generally as described in the plan of improvement of this report, with such modifications thereof as in the discretion of the Chief of Engineers may be advisable, all at an estimated additional first cost to the United States of $10,990,000.

78. The foregoing recommendation is subject to the condition that if local interests do not provide the required local cooperation within three years from the date of the authorizing legislation, or, if prior to the end of the three-year period local interests serve formal notice that they cannot provide the local cooperation, authority for the recommended modifications shall expire and the project shall revert to its original authorization under Section 203 of the Flood Control Act approved July 3, 1958. In this event, local interests shall then be credited with the fair value of any useful work accomplished entirely by them on the original project westward of Interstate Highway 45 to the extent that such useful work is utilized in completion of the original project.

79. The foregoing recommendation shall be subject to the further conditions that local interests agree to:

a. Provide without cost to the United States, all lands, easements and rights-of-way, including all borrow areas, and the relocation of buildings, pipelines, and utilities necessary for the construction of the additional work, at costs presently estimated at $706,000;

b. Bear 30 percent of the first cost, to consist of the fair value of items listed in a above and a cash contribution presently estimated at $4,004,000 exclusivee of $756,000 required as a contribution towards the costs of the authorized project) to be paid either in a lump sum prior to initiation of construction or in installments prior to start of pertinent work items, the final apportionment of costs to be made after actual costs and values have been determined;

c. Hold and save the United States free from any claims for damages due to the construction work;

d. Maintain and operate all works after completion in accordance with regulations prescribed by the Secretary of the Army; and

37 86-965 0-67-4 e. Peven-...aany prmnet ed Ion ithe p idvolume un- lese such is offset roptly by upn Vaity orothri is n t o cost to theUnitedStates.

3 Inc s JOHN E.oUERFER. 1 Plates 2® Appendixe T thru IV DistrictEn gin.7 3 Attachment [Fi-rst oendorsernen]

SUBJECT: RerIen of t _o City Vicinity, Texas (INM-rque

HitchcoW . tnso),rr c an lood Protection

D11vision Eng"meet, v uthwe sternDivsion, Corp of 7EnG-i"Jer, rComme.rce Street , 66

O Chief of g 24ng ,n e h_.AyPT, n, D. ¬

~~R.3 . FREr

Brigadder G nr +s, A Dision Engineer

REVIEW OF REPORT ON TEXAS CITY AND VICINITY, TEXAS (LA MARQUE-HITCHCOCK EXTENSION) HURRICANE FLOOD PROTECTION

APPENDIX I

HYDROLOGY AND HYDRAULICS

TABLE OF CONTENTS

Par. Title Page

1 General------43 4 Project area------43 7 Existing hurricane flood protection project for Texas City and- vicinity------..-.----.----. .-....- 4h 10 Authorized flood control project for Highland. Byou--.---- .. k

11 Climate ------..--- r--- 45 13 Precipitation------.-.---. ---.. 7 14 Rainfall intensities for short period-s----,------8 15 Rainfall intensity - frequency data------...... --- 49 16 Tropical storms------.-----..--.------50 18 Storm surges------...... 50O----- 19 Plans investigated.------.------51

20 Plan A------.------51 21 Plan A-alternate------52 22 Plan B------. 52 23 Plan C------.- -..- .- ...-.-...- 52 24 Plan D------..----...... 3 25 Storm tide frequencies------53 27 Design hurricane.------.. 53 28 Waves------.------54 30 Wave characteristics------....------.. --..----- 54 32 Wave overtopping of levees------. ---- 57 33 Levee crest elevations------57 34 Standard project rainfall storm------..57 35 Other rainstorms investigated.------57 38 Criteria for interior drainage------. 59 39 Interior drainage areas------59 4O Rainfall losses------59 41 Rainfall runoff------59 42 Rates and volumes of runoff------.-.60 44 Gravity drainage structures------60 47 Pump requirements------61 49 Proposed structures - plan A------.----- ...... 61 51 Proposed structures - plan A-alternate------.62 53 Proposed structures - plan C------.------62 54 Interior ponding with proposed improvements------62 56 Tidal interchange------.-.. . 63 58 Operational requirements from hydraulic design------63

41 TABLE ot

A RecordedprCg ipf+ , G i s tt Yin tt Gal ry f v ps vp 'q s Te 'x a A--- v^ B Recorded wind velocities at caivosto, Txas-m---47 C N~ormalt monthly disatributior oif prcipita tion-----i- S Maximum precipitation ser ahout per iods------49 E Rainfall intensity ttfeouenoy data -G&Lveston, Texa-- 49 WSi e oPha.terietics an. r cw ------5 G Selected T4hour raintatws occur rig aoidet wi hig tides -di stributiorn 0 peiitton in 2hu perica ------5

E IB ITS

]1,evee alignments plans A, A:,alternate, and ( 2 Storm tide frequency, Gulf of Ms ico, Galveston 3 Design hurricane hydrograph 4 2h-houx rainfall freque toy 5 Prainage area plan A 6 Drainage area plan A alternate 7 Drainage area plan C 8 Area -ccapacity eures plisPesatv A anda-lenate 9 are - piVy C.Lnve pla141 10 trn sf5 Romping requirements, plons A and Aalternate Bonding stage tfregpuency (cLQG plcc A i4 ending stage frequency curve plan A-alternate Ponding stage - frequency curve plan C REVIEW4 OF REORT ON TEXAS T" FANDOIIN , TEXAS (LA MARQUE-HITC0rCK mEXTENSION) HURRICANE FLOOD PRU17 CT ION

APNDI I

HYDR OLO AND. %UYDRA ICS

I General, This appendix sent data relating t hydrology and lydraul tudes made to investigate severe a plns for a:furding protection from inundation by hurricane surges and flooding by associated interior rainfall to the L Marque-Hitchconk area, hich adjoins the authorized Texas City and vicinity, Texas hurricane flood protection pro jct on the west and southwest. Te athorized . rjdJ.e t for Te &s City and vicinity is under constr tio.

2. The materialincludes the deign an the design hurricane sg the waves that U ttack t protective structure, heightc of wave runup and methods of detemining retired height of the protective structures

3. Also in-luded are descriptions of the various plans investigated, the rainfallthatmay experienced dur periods of both normal and high tides, development of unit hydrograph2 and storm hydrograpbs for the various sbratersheds, and ydraul i data pertinent to the design of the various gravity drainage structures and any ir ed punps. Much of the material presented inthis appendix was developed during construction design studies for the authorized Texas City and vicinity project and has been adapted to this investigation.

1 Project area, The project area is located in Galveston County, southwest of an a cent to the authorized Texas City and vicinity hurricane flood protection project, and included portions of the incorpo- rated cities of Hitchcock and Marque e

5. Highland Bayou is the principal drainage outlet for the project area The HighlandBayou watershed slopes gently from approximate maxnmuaaeeation of 30 feet above mean sea level near Alta Loma, to mean sea level along the shoreline of Jones Bay. The stream is tidal from Jones Bay to Hitchcock. Most of the iStin devlopegynt is located in areiasithelevations o7 7jeet orm re aboFe me an se a level,.

6 .The existing development within the project area largely residential and commer ial, with largeareas resentry in pasture and agricultural use. However, iutrae developments are expected to ocupy most of the agrcltu lands and appropriate allowances have been included. in the computation of interior ;un an' designg diag

8. The interior drainage facilities for the authorized Texas City and vicinity project will include combinations of gravity outlet structures, pumping facilities and temporary storage of ponded runoff in several low areas inside of the protective 'structures. The pumping facilities and gravity outet structures were located and sized on the basis of economic criteria related to the damages that would result from various levels of ponding of interior runoff. The ponding levels for design conditions will not produce excessive damages, either with gravity outlets blocked by high exterior tides or with gravity outlets functioning during periods of normal or low exterior tides. For high tide conditions, temporary "storage in ponding areas, supplemented by pumping facilities, where necessary, provides for holding levels to virtually nondamaging levels for a 30-year rainfall occurring coincident with high tides (9 inches in 24 hours) and, additionally, for holding ponding levels below the point that would cause excessive damages for a 100-year rainfall coincident with high tides (14 inches in 24 hours). For normal and low tide conditions, the gravity outlet structures would hold the levels of temporary storage in ponding areas to virtually nondamaging levels for a 50-year all-season rainfall (14 inches in 24 hours) and additionally, below the point that would cause excessive damages for a 100-year frequency all-season rainfall (17 inches in 24 hours).

9. This study concerns the feasibility of extending the Texas City hurricane flood protection project to afford protection to the adjacent unprotected areas in the western part of La Marque and Hitchcock. It is considered appropriate that the interior drainage criteria for the authorized project be used for this study; except that a standard project rainfall (21.3 inches in 24 hours) be used in lieu of the 100-year frequency all-season rainfall (17 inches in 24 hours) for reasons given in paragraphs 34 and 38 of this appendix.

10. Authorized flood control project for Highland Bayou.- Flood control improvements to provide protection to La Marque and Hitchcock from upstream flooding by Highland Bayou were authorized by the Flood Control Act of 1965. The authorized plan would provide for improvement of the Highland Bayou channel and diversion of flows from an upstream portion of the watershed by construction of a diversion dam and a diversion channel' generally along Basford Bayou to Jones Bay. The

44 report of the Chief of Engineers recommending the authorized flood control improvements is published as House Document No. 168, 89th Congress, 1st Session. Subsequent to submission of the report, the Flamingo Isles subdivision was started along Basford Bayou, which now precludes location of the diversion channel along the originally proposed route. It is now planned that the diversion channel would be rerouted to Greens Lake, as shown on plate 3 of this report. The hydraulic and hydrologic investigations of this study have been made considering the authorized flood control improvements for Highland Bayou, with the proposed revised diversion channel, to be in place.

11. climatee. - The area under investigation is in a humid region with warm summers and mild winters. The proximity of this area to the Gulf of Mexico, the prevalence of southerly winds, and the absence of marked relief result in high relative humidity and uniformity of climate. Freezing temperatures are infrequent and of short duration. Based on data from the U. S. Weather Bureau the mean normal annual temperature (1931-1960) at Galveston, about 9 miles southeast of the area, is 70.1 degrees Fahrenheit. Temperatures at Galveston have ranged from a summer maximum of 101 degrees to a winter minimum of 8 degrees. January, the coldest month, has an average normal daily minimum temperature of 49 degrees, and August, the warmest, has an average normal daily maximum of 88 degrees. These data are indicative of climatological conditions for the area under investigation.

12. The prevailing winds are from the south and southeast and are experienced about 75 percent of the time* North winds are experienced about 13 percent of the time, virtually all during the winter months. Climatological data relating to precipitation, wind velocity and other atmospheric conditions recorded at the Galveston Weather Bureau station are given in tables A and B.

45 TAVLEA

RECORDED PRECIPITATION AT GALVESTON, TEKAS

(Period of record 1871 - 1961)

Normal Maxiluum monthly Maximum : Minimm : in :rainfall(1): monthly(2) : months 2 : 24 hours (3) Month : TchesTa(Inches Year :Inches : Year :(Inches) Year

Jan 3.46 10.39 1899 0.02 1909 5.38 1923 Feb 2.88 10.79 1952 0.09 1954 83.53 1952 Mar 2.86 9.39 1926 0.06 1953 4.58 1944 Apr 2.59 11.04 1904 0.01 1887 9.23 19014 may 2.79 10.50 1929 T 1899 6.13 1916 Jun 2.65 16.86 1961 T 1907 11.34 1961 Jul 4.79 18.74 1900 T 1924 14.35 1900 Aug 4.39 19.08 1915 0.00 1902 9.05 1915 Sep 5.09 26.01 1885 o.o4 1924 10.00 1900 Oct 2.86 17.78 1871 T 1952(4) 14.00 1901 Nov 3.56 16.18 1940 0.03 1903 9.01 1940 Dec 3.89 10.28 1887 0.23 1889 4.50 1884

Sep Aug Jul Year 41.81 26.01 1885 0.00 1902 14.35 1900

T Trace (1) U. S. W. B., "C1imato raphy of the United States,' No. 81..36 (1931 - 1960). (2) U. S. W. B., "Loal Climatological Dat&," Galveston, Texas, 1961, also monthly and annual precipitation records . (3) U. S. 'W. B., "Local Climatological Data," Galveston, Texas, 1961, U. S. W. B., 'Maximuu 2.-Hour Precipitation in the United States," Technical Paper No. 16, Janua 1952, U. S. W. B., "Maximum Station Precipitation for 1, 2, 3, 6, 12, and 24-Hours,'" Technical Paper No. 15,4 Part XXIV, 1959. (4) Also occurred on earlier dates.

46 TABLE B

REC01DED WIND VELOCITIES AT GALVESTO0, TEKAS

Mean :Prevailing: Fastest recorded mile hourly : direction: Speed Direction Month (1.p-h)speed )(2)S; ()( ) m.p.h. (1)(2) Year

Jan 11, SE 53 S 1915 Feb 11.6 SE 60 N 1927 Mar 11.7 SE 50 SE 1952 Apr 11.9 SE 56 N 1952(3) MNy 11.4 SE 60 W 1953 Jun 10.5 S 62 SE 1921 Jul 9.6 S 68 NW 1943 Aug 903 S 91 E 1915 Sep 10.0 SE 87(5) NE 1900 Oct 10.3 SE 66 SE 1949 Nov 11.0 SE 54 N 1950 Dec 11.2 N 50 NW 195+

Aug Year 10.8 SE 91 E 1915

(1) Direction from which wind is blowing. (2) Length of record 81 years. (3) Also occurred on earlier dates. (4) Record not continuous, length 1 0 years. (5) Estimated by U, S. Weather Bureau.

13. Precipitation.- The maximum annual precipitation recorded at Galveston i 76.39 inches, which occurred in 1900, and the minimum annual precipitation was 21.40 inches in 1998. The normal annual precipitation is 41.81 inches . The normal monthly distribution of rainfall varies from a maximum of 5.09 inches in September to a minimum of 2.59 inches in April. The mean monthly distribution of rainfall and the percentage relationship of the mean of each month to the mean of all the months in the year at GaLveston and Houston, Texas, are shown in table C . The variation from average normal monthly rainfall at Galveston ranges from a minimum of 74 percent in April to a maximum of 146 percent in September. The variation at Houston, about 38 miles northwest of the area, ranges from a minimum of 64 percent in March to a maximum of 137 percent in July.

47 TABLE C

NORMAL MONTHLY DISTRIBUTION OF PRECIPITA'TION (1)

Galveston Houston :Precipitation: Percent : Precipitation : Percent Month : in inches : of mean : in inches : of mean Jan 3.46 99 3.72 99 Feb 2.88 83 3.21 85 Mar 2.86 82 2.40 64 Apr 2q59 74 3.42 91 May 2.79 80 4.43 117 Jun 2.65 76 3.83 101 Jul 4.79 138 5.15 137 Aug 4.39 126 3.55 94 Sep 5.09 146 3.81 101 Oct 2.86 82 3.60 95 Nov 3.56 102 4.04 107 Dec 3.89 112 4.10 109

Annual 41.81 45.26

Mean (avg. mo.) 3.48 100 3.77 100

t 1() U.9 1S.6W.0B.pCiatograph of the United States No. 81-36, (1931 - 1960).

14. Rainfall intensities for short eriods.- Rainfall intensities for short periods were obtained from the records of the first-order stations at Houston and Galveston. Table D shows the maximum recorded precipitation at these stations for selected time periods varying from 1 to 72 hours

48 TABLE D

MAX IMM PRECIPITATION FOR SHORT PERIODS

Maximum precipitation Selected periods (in inches) (in hours) : Galveston Houston 21 5.31 4.36 2 7.58 6.05 3 8.78 6.62 6 11.79 8.67 12 12.75 10.02 24 14.35 10.83 72 16.04 10.83

15. Rainfall intensity - frequency data.- The records of the first- order station at Galveston, covering the period from April 1890 to December 1954, were analyzed to determine the frequency of heavy rates of rainfall which may occur in the area. The results of this analysis are given in table E.

TABLE E

RAINFALL INTENSITY - FREQUENCY DATA GALVESTON, TEXAS

Frequency of occurrence : Rainfall in inches (years) :2-hour : 2-hours : 3-hours : 6-hours : 12-hours : 2 -hours 1 1.73 2.37 2.76 3.33 3.85 4.27 2 2.13 2.96 3.50 4.44 5.18 5.66 3 2.40 3.35 3.99 5.20 6.11 6.67 5 2.78 3.89 4.65 6.27 7.28 8.09 8 3.18 4.44 5.31 7.35 8.47 9.46 10 3.38 4.74 5.66 7.89 9.07 10.13 15 3.78 5.32 6.30 8.85 10.08 11.33 20 4.08 5.76 6.78 9.54 10.80 12.14 30 4.53 6.44 7.54 10.50 11.72 13.18 40 4.89 6.96 8.10 11.10 12.24 13.75 50 5.19 7.38 8.58 11.58 12.60 14.21 100 17.00 SPF 21.28

49 16. Tropical storms.- Tropical storms that affect the Texas Gulf coast are cyclonic disturbances that usually originate during the months of June through October in the eastern part of the Atlantic Ocean, near or south of the Cape Verde Islands; in the western Caribbean Sea; and in the Gulf of Mexico. When winds associated with these storms exceed 74 miles per hour, the storms are designated as hurricanes.

17. From their origin the storms generally move in a broad sweeping parabolic curve extending westward and northwestward, then curve northward and northeastward. Those that reach the Texas coast generally move on a west-northwest course into and across the Gulf of Mexico to the coast and curve to the right after crossing the coast. They usually move inland nearly normal to the coastline. The direction of movement of the storms is greatly affected by anticyclonic movements on the continent and the pattern of atmospheric pressure over the Gulf coast states. Some tropical storms have followed very erratic paths, even to the extent of moving southwestward parallel to the coastline before turning to the west and entering southern Texas or Mexico0

18. Storm surges. - The tidal surges caused by hurricanes as they approach and then cross the coast are extremely variable, depending upon the size and intensity of the storm, the position of the point on the coast in relation to the storm path, the rate at which the storm approaches the coast, land and underwater topography in the storm path, and the atmospheric pressure difference between the center and the periphery of the storm. The astronomical tide, which is not affected by the storm, has its effect on the total rise in the water surface. The great storms of 1900 and 1915 crossed the coast southwest of Galveston. Maximum water levels near Galveston of about 14.5 and 12.7 feet above mean sea level, respectively, were indicated by marks found after the storms. The maximum of 12.7 feet in the 1915 storm was estimated at locations a few miles southwest of Galveston, although a water level of 11.7 feet at Galveston is indicated by the Weather Bureau records. An intense storm of small diameter moved inland east of Galveston in 1943, causing offshore winds that depressed the water surface at Galveston to 5.7 feet below mean sea level. Hurricane Audrey in June 1957 crossed the Louisiana coastline between Sabine Pass, Texas, and Cameron, Louisiana, and caused maximum surge levels in the Cameron vicinity of approximately 13.5 feet above mean sea level. This storm produced a water level of 6.1 feet above mean sea level at Galveston. Hurricane Debra in July 1959, a relatively small storm, developed near the shore and generated only moderate surge levels along the coast. The maximum surge at Galveston was 2.7 feet above sea level. However, the storm path was favorable to piling up water in upper Galveston Bay, with elevations of 7.9 feet being recorded at Morgan Point and 9.6 feet in the Houston Ship Channel at Houston. One of the great storms of the century, Hurricane Carla, moved inland at Pass Cavallo in September 1961 and caused a surge of -123 feet above mean sea level near Port O'Connor, Texas, about 130 miles southwest of Galveston. A maximum tide level of 8.8 feet above mean sea level occurred along the shoreline at Galveston during the passage of Carla. Considerably higher water surface elevations,

50 ranging up to 14 and 15 feet above mean sea level were recorded along the westerly and northerly shores of Galveston Bay during Carla. A very large hurricane in September 1919 moved inland south of Corpus Christi, Texas, and produced water levels in Corpus Christi Bay reported from 12.5 to 16.0 feet above mean sea level. This storm caused a tide of 7.6 feet above mean sea level at Galveston.

19. Plans investigated.- Five of the plans investigated to some degree are shown on plate 3 and are described in the following paragraphs. Each plan was developed with the assumption that the recommended channnel improvements and diversion of flows from the upper part of the Highland Bayou watershed, as discussed in paragraph 10 of this appendix, were authorized for construction,

20. Plan A.- This plan provides for an earthen levee that would join the authorized Texas City hurricane flood protection project near the planned La Marque pumping plant. From that point the levee would extend southeastward about one mile to cross Highland Bayou, Texas Highway 6 and the G.C.&S.F. railroad; then turning northwestward along the railroad about one and one- half miles and westward about three and one-half miles to end at the 15-foot contour southwest from Hitchcock. This route would enclose only an additional area that is now generally developed. Outside of the natural stream channels, virtually no ponding area would be available inside the enclosure. A combination tidal control, drainage and navigation structure would be required at the crossing of Highland Bayou. The route would also cross the diversion channel of the authorized flood control for Highland Bayou (H. Doc. 168/89/1), which is now planned to discharge into Greens Lake, as shown on plate 3. A gated structure would be placed in the levee at the diversion channel crossing. During normal tide periods, runoff from the Highland Bayou watershed would be handled by gravity outflow through both Highland Bayou and the diversion channel to Greens Lake, as planned in the previously submitted report. During high tide periods, however, the gates in the structures across Highland Bayou and the diversion channel would be closed and the gravity outflow system would not function. Because of the lack of available ponding, or temporary storage inside the enclosure, pumping would be required to hold the accumulation of interior rainfall runoff to levels where excessive damages would not be incurred. In the interest of pumping at only one location, the plan includes a pumping plant at the Highland Bayou crossing. Flows from the upper Highland Bayou watershed through the diversion channel would be routed to the pumping plant through the borrow ditch channel inside of ahd paralleling the levee. Closure of gates in a control structure to be located in this channel near the diversion channel would direct all flows from the upper Highland Bayou watershed through the diversion channel to Greens Lake during normal t ide periods. The route and features of plan A are shown on plate 3 of this report. Under this plan, only the levee and appurtenant drainage structures in the reach extending northwestward from the La Marque pump station to the terminus near Main Street in La Marque would be eliminated from the presently authorized Texas City hurricane flood protection project. The pumping capacity planned for the La Marque pumping station would be combined and supplemented with additional capacity included in this plan.

51 21. Plan A - Alternate.- Alternate plan A has the same size and type of levee, combination tidal control, drainage and navigation structure and pump station as does plan A and differs only in the diversion system. This plan provides that both during normal tidal periods and during periods of high tides, the rainfall runoff from the Highland Bayou watershed, upstream from the diversion dam, would be diverted out of the watershed to Karankawa Bayou. The plan would provide a diversion dam in the. Highland Bayou channel, approximately three miles upstream from Hitchcock, Texas, and an excavated channel extending southward through Karankawa Bayou into Karankawa Lake, a tributary arm of Galveston Bay, as shown on plate 3. The alternate plan A would have no gates in the diversion system and hurricane tides would be free to pass into the system. Since the banks of Karankawa Bayou and the south bank, of Highland Bayou upstream of the diversion point exceed 15 feet elevation, no overflow from the design hurricane surge would be experienced. The north bank of Highland Bayou upstream of the diversion point, however, is lower than the design hurricane surge. Thus to prevent overflow of the north bank into lower areas to the northeast, a levee extending northward from Highland Bayou near the diversion point is included in the plan. The spoil from the diversion channel would be deposited on the easterly side of the channel to form a continuous embankment from the diversion dam thereby preventing hurricane tides entering the area downstream from the diversion dam.

22. Plan B.- The alignment of the levee under plan B would begin at the same point as plan A and extend south approximately one mile, crossing Highland Bayou, Texas Highway 6 and the G.C.&S.F. railroad, continuing southwestward parallel to the Jones Bay shoreline approximately one and one- half miles; and westward crossing Basford Bayou and continuing approximately five miles to the fifteen foot contour as shown on plate 3. Subsequent to the investigation of this plan, construction of an extensive subdivision was started. This subdivision, Flamingo Isles, shown on plate 3, effectively precludes the construction of plan B, and detailed hydrologic and hydraulic studies were not made.

23. Plan C.- The levee considered under plan C would begin at the same pointaspan A and extend approximately two miles southeastward parallel to Interstate Highway 15; turning southward approximately two miles into Jones Bay to the spoil banks north of the Gulf Intracoastal Waterway; and westward approximately two miles along the Gulf Intracoastal Waterway spoil banks to the mainland, continuing approximately five miles to the fifteen foot contour as shown on plate 3. This plan includes closure structures at the crossings of Texas Highway 6 and the G.C.&S.F. railroad, tidal interchange, drainage and navigation structures in Jones Bay, and a diversion system located in the upper reach of the watershed. The diversion system would be a slight modification of that recommended in the prior report for stream flood control of Highland Bayou. A diversion dam would be built across Highland Bayou approximately two miles upstream from Hitchcock, and an excavated channel would extend southward through the Basford Bayou watershed from the diversion dam to the protection levee. The water diverted from the upper reach of Highland Bayou would then flow eastward in the interior collection ditch adjacent

52 to the hurricane flood protection levee to Jones Bay. During normal tidal periods the water would flow through the drainage, tidal interchange and navigation structures into the bay. During periods of high tides the several outlet structures would be closed and the runoff would be- ponded within the protective levee. As soon as the exterior tide receded below the elevation of the water in storage, the gates would be opened and the ponded water allowed to discharge to Jones Bay. This plan would eliminate construction of the La Marque ptnp station, and the levee and appurtenant drainage structures in the reach extending northwestward from the pump station to the terminus near Main Street in La Marque planned in the presently authorized Texas City hurricane ,flood protection project.

24. Plan D. - The levee considered under plan D would extend from the location of the Texas City pumping plant, of the authorized Texas City hurricane flood protection project, southwestward approximately one mile parallel to Texas Highway Loop 197 to the Galveston, Houston, and Henderson Railroad, then southeastward approximately three-fourths mile parallel to the railroad, then southwestward approximately one-half mile crossing the railroad and Interstate Highway 45. After crossing Interstate Highway 45 the levee would follow the same route as plan C to the fifteen foot contour as shown on plate 3. This plan was eliminated from detailed consideration for reasons not pertinent to hydrology and hydraulics and no detailed studies were made.

25. Storm tide frequencies.- The improvements under consideration in this report would constitute an extension to the authorized Texas City hurricane flood protection project. The additional area being considered for protection, as shown on plate 3, is adjacent to the authorized project, therefore, the hurricane surge elevations developed in construction design studies for that project are also applicable to the area included in this study.

26. Using data and parameters developed by the U. S. Weather Bureau on the occurrence of storms in the Gulf of Mexico and computed water level response at Galveston for a number of hypothetical storms, a storm tide height-frequency curve was developed. A second frequency curve, was drawn based upon recorded storm tide heights at Galveston. The two curves show similar results in the range of large infrequent storms, but diverge considerably in lower storm tide height ranges . The curve based upon hypothetical storms is considered to be somewhat conservative, since it was assumed that each of the storms would cross the coast normal thereto and with Galveston in the region of maximum wind speed. Accordingly, a composite curve was drawn between the two curves, as shown on exhibit 2 of this appendix, and was adopted as the storm tide frequency curve for the Texas City project studies.

27. Design hurricane.- The design hurricane selected for this investigation is the same as that developed from detailed studies for the construction of the authorized Texas City hurricane flood protection project. The storm has an expected recurrence interval of 100 years. This storm has a maximum onshore component of wind velocity, 30 feet above

53 86-965 0-67-5 the water, of 99 miles per hour; a barometric pressure at the center of the storm of 27.54 inches of mercury; a barometric pressure, at the periphery of the storm, of 29.92 inches of mercury, a radius to region of maximum wind speed of 15 nautical miles; and a forward speed of the storm mass of 11 knots. The maximum surge elevation produced by this storm at the coastline is 15 feet above mean sea level. As the storm crosses Galveston Island, the maximum surge elevation will decrease to approximately 13.5 feet above mean sea level on the lee side of the Island. However, the hurricane winds acting on the waters of West Bay will offset this decrease with an additional setup of 1.5 feet, thus producing a surge elevation of 15.0 feet above mean sea level at the proposed hurricane protection structures. The design stogy tide hydrograph is shown on exhibit 3 of this appendix.

28. Waves,. In addition to the rise .in water surface produced by a hurricane, waves generated by the high winds must also be taken into account in the design of protective structures, and for interior drainage of the enclosed areas. The height of waves attacking the structures vary with the fetch, or distance over which the wind acts upon the water, the direction from which the wind is blowing, the speed of the wind, and water depths of the submerged areas in front of the structures. The project area and alignment of the authorized Texas City hurricane flood protection project are shown on exhibit 1 of this appendix. Insets on this exhibit shows the aligment of the proposed plans for extension to afford protection to western La Marque and Hitchcock and the fetch directions for producing waves critical to each of the several reaches of the protective structures included in plans A, A-alternate, and C .

29. The manner of computing the height of waves expected to attack the proposed protective structure, the height of the structure required to provide protection, and the amount of .water that may enter the protected area by waves overtopping the levee are described in paragraphs. 30' through 33. All of the computations are based on the height of the significant wave, which is defined as the average height of the highest one-third of all of the waves expected to occur during the time that the surge is at its peak elevation.

30 O. Wave characteristics.- The results of computations to determine wave characteristics and runup on various slopes of levees for each of the several reaches of each plan studied are shown in table F. The following computations illustrate the xiethod used in computing the data. Only the computations for fetch line "Acf" for plan C are illustrated. All other were computed in a similar .ner.

54 TABLE F

WAVE CHARACTERISTICS AND RUNUP

Wave computations Runup on 1 on : Runup on1 on Runup on1 on 10 Average : : Average :Sig. waves in shallow water: Equivalent deepwater wave values alone.- smooth . slope - smooth slope - smooth Fetch :effective: Wind : depth :iRatio: : :R . : Runup.: :Runup : Runup line wind : : fetch : of : Hs/L H/ H L/Lo L Ratio :factor: Runup : Maximus factorr: Runup Maximu fRunup Maximum on : velocity: length : water : Hs LH: : : H : : :Ho/Lo :RH :R :elevation:R/Ho :RH -elevation 0 : -o: elevation exhibit I: (2) : (3) : (4) : (5) (6) : (7) feet: : ft : ) : (11) : (12) : (13) : (1e) :(15) : (16) : ( feet (18) : f19)et(20) . mt2 (1) : m.p.h.: miles : feet :feet :feet - :_. : :feet: - :feet : -- - :feet :ft.m.s.l.: - :feet :ft.m-s.l. . - ;feet .- 't. m.s. L.

AUTPHCIZED PROJECT

A 82 7.0 18.0 6.7 u6 0.058 0.92 7.3 0.750 155 0.047 0.87 6.35 21.4 0.65 0.51 A' 82 8.0 12.0 5.0 83 0.060 0.93 5.4 0.722 115 0.047 0.87 4.70 19.7 0.65 0.51 U' B 92 20.0 16.2 6.6 no o.060 0.93 7.1 0.727 151 0.047 0.87 6.18 21.2 0.65 0.51 U1 C 93 10.5 21.5 8.0 138 0.058 0.92 8.7 0.750 184 0.047 0.87 7.57 22.6 0.65 5.66 20.7 0.51 4.44 D 19.4 92 10.5 21.5 8.0 138 0.058 0.92 8.7 0.750 184 0.047 0.87 7.57 22.6 0.65 5.66 20.7 0.51 4.44 E 21.6 19.4 92 15.0 8.0 138 0.058 0.92 8.7 0.750 184 0.047 0.87 7.57 22.6 0.65 5.66 20.7 0.51 4.44 19.4 F 67 20.6 20.0 6.4 u8 0.054 0.91 7.1 0.803 147 0.048 0.87 6.18 21.2 o.65 0.51 G 83 20.0 19.4 7.0 122 0.057 0.92 7.6 0.760 161 0.047 0.87 6.61 21.6 0.65 4.94 19.9 0.51 H 3.0 10.0 3.88 18.9 53 3.3 60 0.055 0.92 3.6 0.789 76 0.047 0.87 3.13 18.1 0.65 0.51

A ' 82 8.0 12.0 5.0 83 0.060 0.93 5.4 0.722 3150.047 0.87 4.70 19.7 0.65 3.51 18.5 0.51 2.75 17.8 PLAN C

A' 82 8.0 12.0 5.0 0.060 0.93 5.4 1 83 0.722 115 0.047 0.87 4.70 19.7 0.65 3.51 18.5 0.51 82 4.5 17.5 114 0.058 2.75 17.8 Acl 6.6 0.92 7.2 0.750 152 0.047 0.87 6.26 21.3 0.65 4.68 19.7 0.51 3.67 18.7 AC2 82 17.5 6.6 114 0.058 4.5 0.92 7.2 0.750 152 0.047 0.87 6.26 21.3 0.65 4.68 19.7 0.51 3.67 18.7 82 7.0 16.8 6.3 108 0.058 0.92 6.8 Ac3 0.750 144 0.047 0.87 5.92 20.9 0.65 4.42 19.4 0.51 3.47 18.5 Fetch line "Acli' shown on exhibit 1 (appendix I)

Wind velocity 82 m.p.h. or 120.5 feet per second

Depth 17.5 feet

Wind fetch 4.5 miles (scaled from map)

S 32.2 x 17.5 = .039 (see TR4) 02 (120.5)2

9F U2 32.2 x !i. 5 x 5280 = 53 (see TR4) (120.5)2

gH5 1.45 x 10" 2 (see fig. 15c TR4) u2

Hs 1.45 x 10-2 x (120.5)2 6.6 ft. sig. wave

Ha=. 32.2

Ts- 2.12 ~~6 = 5.45 seconds sig. wave (from Bretschneider)

Lo = 5.12 x 5.452 = 152 feet (see TR4)

d/Lo - 17.5 0.1151 (TRk) 152

Is/Ho = .9228 (see table D-1,TR4)

d/L5, =1539 (see table D-l, TR4)

Ho = 7.2 feet - equivalent deepwater height

Ls = 114 feet - significant wave length

31. The wave runup factors (R/H0 ) shown in table F were obtained from figure 9 of the Proceedings of the American Society of Civil Engineers, Paper No. 3138, "Freeboard Allowances for Wind-Generated Waves in Inland Reservoirs," by Saville, McClendon, and Cochran.

56 32. Wave overtopping of levees.- The levee crest elevations shown in table F represent the elevations to which the significant waves would run up at the peak of the design storm conditions. There would be some overtopping by those waves in the wave train larger than the significant waves. In studies of wave overtopping for detailed design of the authorized Texas City and Port Arthur hurricane protection projects it was found that, when the levees were of sufficient height to prevent overtopping of the significant wave, the volume of water entering the protected area from larger waves was of little consequence to interior drainage problems. Since it is also improbable that the peak rate of wave overtopping during the design hurricane would coincide with the peak rate of runoff, the rates and volumes of wave overtopping during the design hurricane are not included in the requirements for interior drainage.

33. Levee crest elevations.- The locations of the levees for the various plans are shown on plate 3. The proposed levee alignments include sections located both on land and in the bay, which have different design criteria because of foundation conditions. Generally, the crown elevation must be equal to the maximum tidal surge of the design hurricane plus the estimated runup of the significant wave approaching from the most critical direction. As shown in table F,- the minimum required levee grades vary in the several .levee reaches and, in each reach, with the various side slopes. The actual design grade and cross section selected for each reach are dependent also on foundation conditions and location with respect to normal water and land areas.

34. Standard project rainfall storm.- Flood control improvements authorized for Highland Bayou (H. Doc. .16/89/1) would provide protection from the standard project rainfall. Accordingly, for normal tide conditions, this rainfall was used as a criterion for analysis of interior drainage of the areas to be enclosed by the proposed hurricane flood protection improvements. The standard project rainfall storm, developed in the prior studies for the authorized Highland Bayou flood control project, has a 24-hour rainfall total of 21.3 inches.

35. Other rainstorms investigated.- The effects of rainfall from rainstorms of various frequencies were also investigated. A frequency curve was prepared based on the 24-hour rainfall totals from table E. This frequency curve is shown on exhibit 4 of this appendix and indicates the 50-year "tall-season" rainfall (without regard to tide elevations) to be 14 inches in 24 hours.

36. In the project area, tides higher than about 2 feet above mean sea level begin to impair the effectiveness of gravity drainage outlets. The dates of all tides of 2 feet or more were obtained from records at Galveston, and 24-hour rainfall amounts (if any) were tabulated for those dates. A curve was drawn showing the percent probability of occurrence for 2+-hour rainfalls of various amounts coincident with tides of 2 feet or greate:. This curve, plotted on exhibit I, provides an indication of rainfall coincident with higher than normal tides at Galveston, Texas. Although records are somewhat meager, it is recognized that, in the coastal

57 area, the heaviest rainfalls usually are associated with tropical storms or hurricanes. For this reason, it would be expected that the "all-season" and "coincident with high tide" rainfall curves would tend to coincide in indicating occurrences of extremely heavy rainfall. Accordingly, the portion of the "coincident" eurve depicting rainfall greater than 8 inches in 24 hours was adjusted, as shown on exhibit 4.

37. The design hurricane for the project has an indicated recurrence interval of about 100 years *From the adjusted coincident rainfall curve, it was found that a rainfall of 14 inches in 24 hours was likely to be associated with the design hurricane. This rainfall was adopted as a criterion for analysis of the interior drainage problems associated with the high tides and blocked gravity drainage of the design hurricane. The time distribution of this rainfall is tabulated in the first three columns of table G. A 9-inch rainfall in 24 hours, with a recurrence interval of about 30 years, was distributed in accordance with the 14-inch rainfall distribution and is shown in the last column of table G.

TABLE G

SELECTED 24-HOUR RAINFALLS OCCURRING COINCIDETT WITH HIGH TIDES

DISTRIBUTION OF PRECIPITATION IN 2-HOUR PERIODS

Periods : Time in Rainfall depth (2-hours) : hours (1) : (inches)

14- 0.2 0.1 2 -2 0.2 0.1 3 0 0.3 0.2 4 2 0.7 0.4 5 4 0.7 0.5 6 6 0.9 0.6 7 8 1.5 1.0 8 10 2.7 1.7 9 12 4.o 2.6 10 14 1.5 1.0 11 16 0.7 0.4 12 18 0.6 0.4

Total 14.0 (2) 9.0 (3)

(1) Time scale zero is at beginning of rise of exterior water surface in response to hurricane. (2)- Expected frequency of once in about 100 years. (3) Expected frequency of once in about 30 years. 38. Criteria for interior drainage.- Criteria for handling the interior drainage problem were developed in connection with construction design studies for the authorized Texas City hurricane flood protection project, and during studies for the authorized flood control improvements for Highland Bayou (H. Doc. 168/89/1). Basically the criteria provide for two conditions: the discharge of rainfall runoff through the gravity drainage structures during periods of normal tides; and a combination of storage and supplemental pumping as necessary of the runoff during periods when the gravity drainage structures are inoperable because of high exterior tides. The criteria provide that no serious damage should be experienced from the interior accumulation of runoff from a 1k-inch rainfall in 24 hours without regard to exterior tides. This rainfall might be expected once in about 50 years. The criteria also provide that no exceptionally large damages should be experienced from the interior accumulation of runoff from the standard project rainfall of' 21.3Ainches in 214 hours during normal tide conditions. Further, the criteria provide that no serious damages should be experienced from the interior accumulation of runoff from a 9-inch rainfall in 24 hours during high tide periods, which might be expected once in about 30 years. The criteria provide finally that no exceptionally large damages should be experienced from the interior accumulation of runoff from a 1k-inch rainfall in 24 hours during high tide periods, which might be expected once in about 100 years.

39. Interior drainage areas.- The hurricane flood protection levee around the project area wo inercept drainage that is now discharged into Jones Bay through natural channels, excavated ditches, and by overland flow. The drainage areas and their subwatersheds for plans A, A-alternate and C are shown on exhibits 5, 6 and 7 of this appendix. These drainage areas are characterized by low upland areas w th little slope. The natural channels are shallow and of generally small cross sectional area. Except where improved, the channels are highly sinuous and generally support a luxurious growth of aquatic vegetation along the banks. In the upper reaches where flows are intermittent, vegetation extends across the entire channel.

40. Rainfall losses.- No data were available to permit studies of the initial losses and infiltration indices for the project drainage area. However, extensive investigations of this nature have been made in the Buffalo Bayou watershed in Houston, Texas, which is somewhat similar to the project drainage area. Based on these studies, an initial loss of 1.0 inch and an infiltration index of 0.1 inch per hour were adopted for the project area, and were applied to the 24-hour rainfalls to determine the rainfall excesses.

kl. Rainfall runoff.- The amount of rainfall excess was determined by subtracting the initial loss and infiltration indices from the total rainfall. This excess was used as a basis to develop the inflow hydrographs from the various rainfalls for the several drainage areas under study. The total rainfall excesses for the 9, 1k, and 21.3-inch rainfalls in 24 hours were computed to be 6.4, 11.4, and 18.5 inches, respectively.

59 42. Rates and volumes of runoff.- Synthetic unit hydrographs were developed in order to determine the rates and volumes of runoff from the various subdrainage areas. There are no observations of both rainfall and runoff in the Highland Bayou area available for determination of values of Ct and 640 Cp., Values of these coefficients were estimated from somewhat similar areas on Buffalo Bayou watershed, in the vicinity of Houston, Texas, where actual discharge measurements have been obtained and the coefficients evaluated. The adopted values for coefficients, used in this investigation of providing hurricane flood protection for the La Marque-Hitchcock area, are the same as those used in the Texas City and vicinity, Texas hurricane flood protection project.

43. Inflow hydrographs for the various frequency rainfalls were developed by applying the rainfall excesses to the unit hydrographs developed for each drainage area. These rates and volumes of r off were used to determine the number and size of gravity drainage structures and pumping capacity required for design ponding stages in each plan investigated.

44. Gravity drainage structures.- Gravity drainage structures consisting of combinations of gated navigation structures and gated conduits would be provided for the removal of rainfall runoff during normal tidal periods. The gated navigation structures would provide openings of a size determined by the need to maintain existing navigation within the areas to be enclosed by each plan. Under existing conditions small pleasure craft navigate the lower reaches of Highland Bayou, while barges, derricks, towboats, drilling vessels and dredges use the waters of Jones Bay for oil exploration, drilling and construction activities. For maintenance of existing navigable conditions, the Mghland Bayou channel would require a clear width of at least 20 feet and a clear depth of 10.4 feet below mean sea level, the depth established by the bottom gradient of the authorized flood control project for the stream. Jones Bay would require a clear access width of 56 feet and a clear depth of 13.4 feet below mean sea level, the same depth as the nearby Gulf Intracoastal Waterway (minus 12 feet, mean low tide datum). Closure structures must provide at least these dimensions to maintain ample clearances for traffic into the natural navigable waters of Highland Bayou and Jones Bay. Structurally, the navigation structures would consist of vertical concrete side walls and a sill set at the required depth. Hydraulically, the structures are considered to be a rectangular channel during periods of normal tides.

45. The gravity drainage structures consist of conduits through the levee with automatic flap gates on the outlet end and a well with a riser head gate near the center of the levee. This structure functions as a rectangular channel during periods of normal tides. The rainfall runoff from the protected area was routed through the openings of the navigation and gravity drainage structures. The results of the routing are given in paragraphs 49 through 53. In the routing, the navigation opening was considered as fixed by navigation requirements and the additional cross sectional area required was provided by conduits through the levee.

46. Gravity flow discharges through the various structures are a function of the cross sectional area, interior ponding stages, and the exterior tailwater levels. Rates of discharge for the various structures were determined by using methods presented in EM 1110-345-284. 60 47. Pump requirements.- During periods of high tides the gravity drainage structures are inoperable. When a hurricane forms in or moves into the Gulf of Mexico, the gates of all such structures would be closed prior to an appreciable rise of the exterior water surface. The gates would not be opened so long as the exterior water level was higher than the interior water level or until after passage of the storms.

48. Area capacity curves for the ponding area of plans A and A-alternate are shown on exhibit 8 of this appendix. Similar curves for plan C are shown on exhibit 9 of this appendix. The available capacity for temporary storage or ponding in the enclosed area for both plans A and A-alternate are insufficient to contain the runoff from the selected rainfalls during periods of high tides without ponding to elevations that would produce excessive damage from flooding. In order to hold the ponding elevations to acceptable levels, pumping facilities must be provided to discharge the excess volume of runoff. The tentative pump capacities were determined by methods given in EM 1110-2-1410 and as shown on exhibits 10 through 13. The results of these computations indicate that for plans A and A-alternate, the pumps should have capacities of approximately 1,900,000 and 2,200,000 gallons per minute, respectively. These pumping capacities would limit the ponding elevations from the 14-inch rainfall in 24 hours to 6.1 and 5.9 feet above mean sea level for plans A and A-alternate, respectively. The pumping facilities would be located adjacent to Highland Bayou at the crossing of the proposed protective structures.

49. Proposed structures - plan A.- The routings of runoff from the area that would be enclosed under plan A showed that, during periods of normal tides, a 20-foot wide navigation structure with its sill at a depth of 10.4 feet below mean sea level, as discussed in paragraphs 44 of this appendix and 41 of the text, and two 10-foot by 15-foot gated conduit structures would be required in Highland Bayou. These structures would limit the elevation of ponding in the lower reach of the watershed to 3.5 feet and 5.0 feet above mean sea level for the rainfall runoffs from the 14-inch and 21.3-inch rainfalls, respectively. Four 10-foot by 15-foot gated conduit structures would be placed in the diversion channel from the upper part of the Highland Bayou watershed to Greens Lake. These structures would limit the elevation of ponding of runoff from a 21.3-inch rainfall to 5.8 feet in the diversion channel and adjacent low areas.

50. A channel to be located inside of and parallel to the levee between the upper and lower parts of the watershed would contain an additional gated structure with four 10-foot by 15-foot gates. During normal tidal periods these gates would remain closed and all rainfall runoff from the upper watershed would be discharged through the diversion channel to Greens Lake. During periods of high tides the gates in the diversion channel to Greens Lake would be closed and the gates in the channel paralleling the levee would be opened, thus conducting flows from the upper watershed to the ponding area and pumping station at Highland Bayou. A pumping plant with a capacity of 1,900,000 gallons per minute is required to limit ponding elevations to 3.5 feet and 6.1 feet above mean sea level for the 9-inch and 14-inch rainfalls, respectively, under this condition.

61 51. Proposed.strctures plan A-altert utnlY~gs f run 01

" rw 5 from the area that would be enclosed unUer plan A so Jha ,u

rt during periods of normal tides a 20-footis l a a d t® e b;4 :t its sill at a depth o 10.4 feet belo a and six 10-foot by l5-foot gated cmduit structure 2 , .t Highland Bayou. These structures oud mt 4hE nd in the lower reach of the watershed t 6 n would C)e' 2t 2 level for the rainfall runof rom thle 14 Tnh a G::.: be reur e ,1 , respectively. During periods of highcd he r e. - Ct allowing rainfall ruoff to pon iithn 1 thefprtat L}i "o A uo pinig 2uLd1 1ere2 facility with a capacity of 2,y2 u0,r0 1allon pe9 O ie to limit ponding elevations to 2.0 feat a-y

this plan ro. o' 'lw ) rom ( he p 52. U ne r 'r)gh1n1'02y);u watershed wo u l thr'ugh an op0 n lhrn e tak s t r e s w o u l d d Csr:2 n o c o nt r o l r uc t u b e r e5 3 . P r o p o shd youand'Lak 21nd ate21222 53. _Pro'sle' st "'urg" -s pla e rotn 2 area that would be enclose under p1an C sho '2hat duri run' 2 4 f' h tides a 56-foot wide ma gaton str c with Vs Se^,:1L pe2d fnra C)dp' '1Vf 2AY 13.4 feet below mean sea leve , di = n p ,a r h ) as C) 1> thi< 2'ppendix1 and 41 of the text a -X 5- 02t 2 3- j strctr2 )ould be required in Jones Bay. These QCAu) Kl JKi C, pondin to 3.2 feet and 5,3 feet above eo m"a" s the 14-inch and. 21Q 3-inc rainfallu, re' sseCtiv}ly ,uri tides the rainfall runoff from the h y

within the protection system unt L the xt$ rI r - , tion of the water in storage. At thIs) wt e h tat k., .n t the water in storage would fl ow u The m3 6 fe t a dle .9 ; 2 9 unc be 3.6 feet and 4.9 feet abo'e mean e1' 2 l l 'o 2th 22)ru ol and 14-inch rainfalls, respectively

54. Interior pd6 w'th roposwdC imro rnK'A mm' fieVld

investigation was made to dt ermne 'i the a "pa N l 2- pnding 2 runoff within the project aware The w .!o)V' eleo p ng of r 2" Vno om various rainfalls that 5 0ay . o 5cur 'uring peri'ds o{ "or a e 1)d ' n' d ri periods of tides higher than normal u'r 2cmpe1d for plan A, Awa'ternate and C and are shown o exhibitse, S', and~c 9" th appen12x1 estimated elevations of ponn gfrom larg and less re n sto"2s 2re shown as extension of the 0 "mputed 0 cuve VC'The 2rit'ria 9:r deter22i22n these elevations are gi en in p'a rarah "2 'Dl 129this appi

55. Rapid grow 'of 0 "na1 ty" 'y2 d,5a experienced in the areas under inve ia'iro2 2 9,

pondn volume will be available theseex se l na' extensive fill of low ara that accompa th e ry ~4 co nr tin However, an allowance wa made for thevolu oe lo 11ying Cra adja''112 temporarily ponded in the many charnmn I d boa C," basis wihinthese 02 he&9 '"2. ("2 Clo2 nt n developments. The total available p2ndg ar'o Jh12' inc'ude )-2 wa'er surface area of Jones Ba and Higiand B'yiu> C)' to the existing and plc:nd " aa21 y".p e .. :f < can , nd ba> si wi in the development. The exact location of some R, h p d haEn and i s- f projected developments is not known al nhi im.7 h'ew the areas of ponding have not been indicated on drep,ry drawing the d

5 , 'Tidal rf-- ieT a rae of tide deterEned by the Uotl . C^' s tl2e7rwyq for >eat Bay is 1.0 feet. This tidal range s F'n de red I , B>ap tab tp J o B

II ynspection of

thw "dy s r n nate. Although found to vary, the th tBaTI yc 4h had ti intervals generally as listed below. h tidyd were found to vary longer and hgh tide.

x - Avg. length- T. Of t me hours of time (hours) Fr mTo to :complete phase

/ 8 7 I Stand 5 high tido 1 7 3

-h id to it ow tid 9 10 Stad at o td I 74

:wt ry 9a aweragg cw ag depth of about 2 feet below mean 57..Jone

( ,. S Vi-j " o J, ,es- ,Bay 4ihin the proposed protection system n, s -ilesV and the volume of the tidal prism e ut,20 acre-feet. The gates of the navigation Sw be open during periods of normal tides, per- d.'ttn - the floe f nerintn out of the enclosed portion of the bay pig (omuitations based on the volume of the h4r diffrntial head on opposite sides of the

st 4',rs ) S atthe toal cross sectional area of the proposed Sr, vid apprombte.y normal tidal interchange between . T mptatIone show that over 80 percent of the ri willv, into the closed area of Jones Bay in the West yB y y a F J.-gnng of a rising tide and the beginning

g iie 4 yle. The sr e volume of water would

retrin the longer period between the beginning id . ndY4e baegnn n4 g of the subsequent rising low tide. ut4fte L. a.o, r odso o ma.$L tides construction of the Itwa conL ;r >ksy would have no material hriae I mac oss the bay , '. l uegimn 4f the ater in the enclosed portion of Jones

IV82 'oU naor;ret; Iro hg'rau&ic_.design.- Uydaulic etuae of & he pcoposeeU 3uroanxe flod Protection system require preparation Vd >ration at the a struc>us l in ad ance of hurricanes moving across aesterna portion o th a u (lf of Mxi o, and prior to any appreciable tidal rise at the project area. For hydraulic design purposes, it was assumed that the. preparatory measures would provide for closure of the slide gates in the conduit structures and closure of the navigation structure prior to the beginning of intense rainfalls, and that the gates would remain closed until recession of the hurricane tide, then opened. This time allowance for advance preparation will provide sufficient time for responsible personnel to take the necessary steps of readiness without exposure to the hazardous and adverse conditions that accompany intense tropical storms.

64 86-965 0-67 (Face p. 64)

n- 0 AMARILLO 10 LAM 0 M A 'a ANR. Cl) MEXICO 0

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sTA. 0+ % ~+ PROPOSED STORM STORM ,PROPOSED PROTECTION IMPROVEMENTS 1' PROTE CT ION IMPROVEMENTS

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-PA A N_ PLANS A, A-ALT. AND C

z C 0 x CA TO ACCOMPANY REVIEW REPORT H- FILE NO. GAI.L. 30C- 250 hI

ei C) 0

0U1 20 m COMPUTATIONS BASED ON FREQUENCY m OF CENTRAL PRESSURE INDEXES IN z W.8. MEMO HURRICANE 2-4 C) z rri -J m U)10 C') SM -

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0.1 0.5 2 4 10 30 100 m NUMBER OF OCCURRENCES PER 100 YEARS TEXAS CITY AND VICINITY, TEXAS (LA MARQUE-HITCHCOCK EXTENSION) HURRICANE FLOOD PROTECTION STORM TIDE FREQUENCY N GULF OF MEXICO

x GALVESTON

U.S.ARMY ENGINEER DISTRICT, GALVESTON, TEXAS DEC. 1965 m c z TO ACCOMPANY REVIEW REPORT cl)

FILE: GALV. 308-250 15 C7) f 0

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04 P1

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TEXAS CITY AND VICINITY TEXAS

Li (LA MARQUE- HITCHCOCK EXTENSION) HURRICANE FLOOD PROTECTION U- 0 z DESIGN HURRICANE HYD ROGRAPH

/ S, ARMY ENGINEER DISTRICT GALVESTON, TEGAS DEC. 965 LU -J

TO COM PANY LU I.. REVIEW REPORT r, 0

a x 0LI6 I

T 4 r fi 2

ST 0 2 T 4 A 22 T IME iN HOURS FROM START OF WAT ER SURFACE FHSE C

Ri":iA L AFVi ALL AC20MPANYICG DES HUR'CAN TEXAS CTY AND VICNITYTEXAS (LA MARQUE-HITCHCOCK EXTENSION) HURRICANE FLOOD PROTECTION

24 - H0UR OAI NFALL FE0 CURVE LOT TED FRO TAEL.. E (ITHOUT C tNGDEINT T DES u sA RMY ENGINES GIST TGOALVESTO TEXA DEC 1965

TO ACCOMPANY REVIEW REPORT ! j E G A2FIE:GAL. -250 Q

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t I~~ 6 HD EXPERIENCED RAI NFGRAT COINCIDENT WITH 2 FEET M. S. L. OfR: GREATERt.. 4 r2 z 2L _ Z u u ' 99.9 . 0.2 0.5 I 2 WP ww Ql W --.- --. w PERCENT CHANCE OF OCCURRENCE PER YEAR

U. S. ARMY PAOOQ Ac curtucrDC

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MISETHG1.83 UPPER LIMIT N R OF PROJECT

1764

XAS CITY

GALVESTON - - 7E38:.69 MILE "-'AEpNDR -:- - - - PA6- -

Z OP OFIT BUNARESDIERIO CANELI

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AUTHORIZED FLOOD CONTROL IMPROVEMENTS PROPOSED REVISED - G ALV ESTON

DIVERSION CHANNEL IN - 7 CITY BOUNDARIES- FLOOD CONTROL PROJECT

DO STATE HIGHWAY (RESTUDY IN POST Ii AUTHORIZATION PLANNING) - U. S. H IG HWAY Ra

INTERSTATE HIGHWAY ;-_- - . TEXAS CITY AND VICINITY, T EXAS ( LA M ARQ UE - H ITCHCOCK EXTENSION) x ...... - ~DRAINAGE LAT ERAL--..+- HURRICANE FLOOD PROTECTION

AUTHORIZED TEXAS CITY - DRAINAGE AREA PLAN A -HURRICANE PROTECTION - - --- " -" SCALE OF MILES O STRUCTURES- n BAYOU DRAINAGE f-GR-.S U.S RYEGNEER DISTRICT GALVESTON,TEXAS DEC. 1965 UNDE- RPLANAAREA'---AN ~HIGHLAND -

///DIVERSION CHANNEL DRAINAGE:..' TO ACCOMPANY REVIEW REPORT - AREA UNDER PLAN A FILE: GALV. 308-250

EXHIBIT 5 APPENDIX I I

- U. S. ARMY CORPS OF ENGINEERS N

.83 up tE 1

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EXHIBIT 7 APPENDIX i

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FILE: GALV.308-250 -- I EXHIBIT 10 APPENDIX I I

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FILE: GALV. 308- 250 -- I EXHIBIT II APPENDIX I I

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TO ACCOMPANY REVIEW REPORT

FILE: GALV. 308- 250 .. EXHIBIT 12 APPENDIX I I

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FILE: GALV. 308-250 EXHIBIT 13 APPENDIX I __

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APPENDIX II

PROJECT EVALUATION

TABLE OF CONTENTS

Par Title Page

1 General------.------76 EXTENT AND CHARACTER OF FLOODED AREA------76 PROPETY VALUES------77 5 Existing d-evelop-ent------77 6 Estimated value of property in the area subject to flooding-- 77 FLOOD DAMAGES------778 7 Classes of damages------78 9 Damages from experienced hurricane tidal floods------78 10 Damages from the design hurricane tidal surge------79 11 Average annual damages under existing conditions------'79 12 Residual damages------.---- 79 BENEFITS------79 13 Benefits from damages prevented to existing development------79 14 Benefits from damages prevented to future growth and development------80 17 Intangible benefits------81. 18 Summary of benefits------81 19 Comparison of benefits and cost------82 PROJECT FORMULATION------82 20 Plans considered------82 21 Selection of plans------82 23 Selection of design------T------82

TABLES

A Value of Physical Property in the Flooded Area of the Design Hurricane Flood, Existing Conditions------78 EXHIBITS

1 Stage-Damage Relationship 2 Stage-Frequency Relationship 3 Damage-Frequency Relationship 4 Economic Base Study 5 Economic Base Study Map

75 REVIEW OF REPORT ON TEXAS CITY AND VICINITY, TEXAS (LA MARQUE-HITCHCOCK EXTENSION) HURRICANE FLOOD PROTECTION

APPENDIX II

PROJECT EVALUATION

1. General.- This appendix presents the economic evaluation of the proposed modification of the existing hurricane flood protection project for Texas City and vicinity, Texas, to extend protection to the presently unprotected portion of La Marque and the adjacent city of Hitchcock. The evaluation study is presented in five sections, as follows: (a) extent and character of the flooded area, (b) property values, (c) flood damages., (d) benefits, and (e) project formulation. The section on the extent and character of flooded area describes the flood plain and the type of improvements in the area subject to flooding from a hurricane tidal surge. The sections on property values and flood damages contain an estimate of the value of physical property, and estimates of flood damages that occur to existing property, as well as damages that would occur to future developments in the flood plain. The section on benefits describes and presents estimates of the benefits that are expected to accrue to the plans of improvement investigated in this report.

2. The estimates of values, damages, and benefits are based on data obtained from field surveys, and information submitted by local interests at the public hearing. Aerial mosaics, field surveys, and quadrangle sheets were used for delineating the flood plain for the collection of data on property values and flood damages. The area subject to hurricane flooding that was investigated in detail is shown on plate 3 of the report.

EXTENT AND CHARACTER OF FLOODED AREA

3. The La Marque-Hitchcock area subject to flooding by hurricane tidal surges is roughly rectangular in shape and contains about 28 square miles. The area extends up to 10 miles inland from the shoreline of West Bay to the 15-foot contour elevation, and occupies approximately 5 miles of bay shoreline. Portions of the cities of La Marque and Hitchcock are within the area subject to flooding by hurricane tidal surge. The older section of Hitchcock is located on a small island of ground higher than the 15-foot contour. Undeveloped parts of the area subject to hurricane flooding are mostly prairie, and most of the land is lying idle, although some is used for farming or grazing. There is little or no industrial development in the low area at present.

76 4.9Anumber of the more recent residential developments have been located along the banks of Highland Bayou. Several new resort- or canal- city type developments have been located in areas of very low ground. In this type of development, a system of interconnecting canals are excavated to afford small-boat access to the residential sites. The excavated material is deposited on the adjacent lots to raise the ground elevations for building purposes. Many of the residences are constructed on piles or stilts well above the ground elevation. In several of the developments, the land areas have been raised to an elevation of 5 feet above mean sea level. Very recently, plans have been announced for a new 3,900-acre residential community of the canal-city type to be located near the mouth of Basford Bayou. Construction of some of the canals has been started and the adjacent land is being elevated with fill to approximately 8 feet above mean sea level, which will afford some protection from moderate storm surges. So far as known, promotional sales activities have not been started for this area. The development has been designated as Flamingo Isles.

PROPERTY VALUES

5. Existing development.- The majority of residences in the area subject to flooding were built during the last 15 years. Generally, the older buildings are on low foundation piers and have wood or asbestos shingle siding. Mny of the newer homes have brick veneer exterior walls and are built on slab foundations. Along the waterfront areas, the buildings generally are high elevated wood frame resort homes on wood or concrete piling. About half of the resort homes are used as permanent residences and the remainder are occupied mostly on weekends and during the summer months. Commercial properties include the normal businesses for servicing the needs of residents in the area, i.e., grocery stores, service stations, hardware, appliance stores, etc.

6. Estimated value of property in the area subject to flooding.- Estimated values of property were based on field survey of the area and information obtained from realtors, investors and tax valuations. The value of existing physical property in the flood plain of the design hurricane flood, which has an expected recurrence interval of about 100 years, was estimated in December 1965 to be $25,692,000. Table A presents estimates of the values, classified by use, of existing properties within the flood plain.

77 TABLE A

VALUE OF PHYSICAL PROPERTY IN THE FLOODED AREA OF THE DESIGN HURRICANE FLOOD, EXISTING CONDITIONS

Type of property Value

Residential $17,17x,000 Resort 1,625,000 Commercial 1,776,000 Municipal 1,653,000 Utilities 937,000 Roads and railroads 2, 527,000

Total 25,692,000

1December 1965 estimate.

FLOOD DAMAGES

7. Classes of damages.- Damage estimates are based on data obtained through field surveys and physical inspection of all properties in the flood plain of the design hurricane flood. Primary damage estimates were made for various types of physical property classified by use as residential, resort, commercial, municipal, utilities, roads and railroads, and for various types of nonphysical losses. Estimates of damages are based on the type of loss, the kind and value of structure or improvement, depth of inundation and location. These estimates include the battering effects of wind and wave-driven floating debris where appropriate.

8. Secondary damages, such as loss of production, additional transportation cost, or loss of wages outside the area of influence of the project were not evaluated. Loss of life and residual adverse effects related to public health, security, and national defense also were not evaluated.

9. Damages from experienced hurricane tidal floods.- Prior to 1940, development was sparse in the area subject to flooding, and records of damages from hurricane floods are not available. After World War II and the industrial expansion at Texas City, construction of a number of new residential subdivisions began in the La Marque-Hitchcock vicinity. Since 1957, the area has experienced three floods ranging from minor to serious as a result of hurricanes and related rainfall. On 25-27 June 1957, hurricane "Audrey" moved inland with devastating effects at Cameron, Louisiana, about 130 miles northeast of the Hitchcock area. The fringe effects of this storm produced minor flooding and damages in the study area. On 24-25 July 1959, hurricane "Debra" struck the upper Texas Gulf Coast near Freeport, Texas, with moderately high tides accompanied by very heavy rainfall. Damages

78 from tidal inundation in the La Marque-Hitchcock area were estimated at $100,000. Tidal flooding up to elevations about 13.0 feet above mean sea level, during hurricane "Carla" in September 1961, produced estimated damages of about $2,350,000. A tropical storm, "Cindy,'" moved inland near Sabine Pass, about 80 miles to the northeast of Hitchcock, on 16-20 September 1963. Tides were not high during the passage of this storm and the principal damages resulted from torrential rainfall in some areas. The storm produced practically no damage in the study.area.

10. Damages from the design hurricane tidal surge.- The design hurricane would produce an estimated tide level of 15 feet m.s.l. in the La Marque- Hitchcock vicinity. Inundation of the area from the design hurricane surge would damage approximately 1,700 buildings in an amount estimated at $6,375,000 for the present state of development in the area covered by plan C.

11. Average annual damages under existing conditions.- Estimates of average annual damages were computed by correlating the stage-damage relationship with the stage-frequency relationship to establish the damage- frequency relationship. The average annual damages are determined from the area under the damage-frequency curve. The average annual damages for existing conditions were determined for each study area contained in the various plans of improvement. A stage-damage curve was developed for each study area and plotted with the one stage-frequency curve for hurricane surges to establish the damage-frequency relationship for each study area. The various plans are described in appendix III to this report and the levees for each plan are delineated on plate 3. Stage-damage, stage-frequency, and damage- frequency curves used in determining the average annual damages for plan C are shown as exhibits 1, 2, and 3 of this appendix. The total average annual damages for present development in the area to be protected are estimated at $266,300.

12. Residual damages.- The several investigated plans of improvement would afford protection to the La Marque-Hitchcock area for the design hurricane tidal flood with coincident rainfall. Under each plan some remaining, or residual, damages would still occur with the proposed improvements in operation. The residual damages would be experienced from hurricanes larger than the design hurricane and from hurricane related rainfall that would be ponded during high tidal surges. Average annual residual damages that will be incurred with the improvements proposed under plan C are estimated at $10, 300.

BENEFITS

13. Benefits from damages prevented to existing development.- Bene- fits would accrue to the plans of improvement investigated in this report through the prevention of tidal flooding damages that are incurred by property under existing conditions. The average annual benefits to existing property would be the average annual damages that are now occurring less

79 the residual damages that would still occur with the proposed improvements in operation. As shown on exhibit 3 of this appendix the average annual benefits that would accrue to existing property under improvement plan C are estimated at $226,000.

14. Benefits from damages prevented to future growth and development.- Growth and development of the La Marque-Hitchcock area will be in consonance with the overall growth and development of the mainland portion of Galveston County without hurricane protection. As discussed in the economic base study in exhibit 4 of this appendix, a projected average annual growth rate of 1.6 percent may be expected for the period of evaluation of 100 years. The total land area in the flood plain is about 18,000 acres, of which 3,000 acres are occupied by existing residential and commercial developments.

15. Part of the planned 3,900-acre Flamingo Isles development is included in the allowances for normal growth and development. Flamingo Isles is a recreationally oriented residential community containing all of the normal business, schools, churches, etc., with. interconnecting channels for small boats. If completed to the present long range plans, the Flamingo Isles development probably would have a total value exceeding $150, 000,000. The initial investment by the developers for Flamingo Isles development is estimated at $5,000,000. This investment is being used to excavate a series of connecting canals in patterns designed to afford small boats access to each lot. The excavated material is being used to raise the adjacent ground to elevations of about 8 feet above mean sea level. Bulk- heads and retaining walls will be installed along many of the canal banks. Other facilities to be installed with the initial investment include roads, streets, utilities, and community service and recreational facilities. The probable success of this type of development at this location has been demonstrated by the very similar and nearby Bayou Vista, which was started several years ago and is currently in its third expansion unit. Plans for a similar development to be located on Wilson Point in Jones Bay and known as.,"T'iki : land" h ve beenrecently annocaed in newspaper releases. Numerous other similar developments have been made, both in the immediate area and along the Texas coast in general, in the last 10 years. They, have proven to be very popular and attractive both for permanent residences and for temporary or second-home occupancy for water oriented recreation purposes. To recover the initial $5,000,000 development cost, the first unit will include about 720 acres. It is estimated that full development of this area will occur in about 10 years. Based on a probable 4 houses or dwelling units per acre and an average value per unit of about $13,000, it is estimated that by 1975 this area will have a total valuation of about $25, 960,000, comprised of $23, 940,000 residential property, $320,000 marina, $71, 000 recreation center, $909,000 utilities, $720,000 streets and roads. Since the first unit of Flamingo Isles is an active and definitely committed development now under construction, it has been taken into account individually in estimating

80 benefits for future growth and developent. Since the remainder of the projected Flamingo Isles development is not as definite in commitment, it has not been recognized individually in the estimates of future growth but would be included in the general growth rate of 1.6 percent annually indicated by the economic base study, which has been used for estimates of benefits from future developent.

16. The average annual equivalent benefits are developed according to the formula and procedures described in EM 1120-2-118, appendix II, and Senate Document 97, 87th Congress. Using an interest rate of 3-1/8 percent and a period of evaluation of 100 years, the damages prevented to future growth and developent have been reduced to an average annual equivalent value. For the initial developent unit of Flamingo Isles, an average value per structural unit was estimated and applied to the growth estimated for the 10-year development period as discussed in paragraph 15 above. Based upon exposure characteristics and compared with average annual damages per structural unit estimated for existing developent in the area, average annual damages per structural unit were estimated for the projected development in Flamingo Isles. The annual damage for the total number of units in the tenth year of development is estimated at $451,700. This total of annual damages was assumed to remain constant for the remainder of the 100-year project life. Based on these assumptions, the average annual equivalent benefit for damages prevented to the Flamingo Isles' initial development, computed at 3-1/8 percent interest over the 100-year period, amounts to $451,700 X .868 or $392,000 (rounded) annually. (EM 1120-2-118, Chg 3, APP II, Table 2.) In a like manner, equivalent average annual benefits from the remaining future developments were computed on a 1.6 percent compound growth rate for the 100-year period, as follows: $226,000 X 4.892 = $1,105,592. The remaining damages prevented to future growth are reduced to an equivalent average annual benefit of $1,105, 592 (-) $226,000 X .282 - $248,000 (rounded) annually. Total equir.lent average annual benefits from prevention of damages to future growth and development are estimated at $392,000 to the initial unit of Flamingo Isles, and $248,000 to the remaining future development, or a total of $640,000 annually.

17. Intangible benefits,- In addition to the tangible benefits which have been evaluated, certain benefits include the elimination of loss of life, improved sanitary conditions, and reduction in fire hazards during hurricanes. Such benefits cannot readily be expressed in monetary terms and have not been evaluated in this report.

18. Summary of benefits.- The1 total estimated average annual equivalent benefits creditable to the proposed plan of improvement, evaluated on the basis of December 1965 prices, are summarized as follows:

a. Hurricane flood damages prevented to existing development $226,000

b. Hurricane flood damages prevented to future developents 640,000

Total average annual benefits 866,000

81 19. Comparison of benefits and cost.- The estimated annual charges for the proposed plan of improvement are presented in detail in appendix III to this report. Average annual benefits were estimated as described in the foregoing paragraphs. Comparison of annual benefits to annual charges and the benefit-cost ratio for the recommended plan of improvement are summarized as follows

a. Total average annual benefits $866,000

b. Annual charges 597,000

c. Benefit-cost ratio 1.

PROJECT FOULATION

200 Plans considered.-m In determining the most feasible plan for hurricane protection, five plans were given some degree of consideration for protecting the study area from damages caused by tidal flooding. These plans were designated as plan A, A-alternate, B, C, and D. The plans are described in paragraph 32 of the text of this report and are shown on plate 3.

21. Selection of plans.A As discussed in the text, plans B and D were eliminated for reasons other than economic considerations. Economic analyses were made for plans A, A-alternate, and C.

22. The estimated annual benefits, annual charges, excess benefits over cost, and benefits-to-cost ratio for the plans A, A-alternate, and C are summarized as follows:

Annual Annual Excess benefits B/C Plan benefits Charges over cost ratio

A $376,000 $)74,7000 0.8 A-alternate 376,000 496,000 0.8 C 866,000 597,000 $269,1.4

23. Selection of design. - As shown above, only plan C was found to have a favorable benefits-to-cost ratio and was selected as the plan of improvement. The improvements considered herein, if authorized and constructed, would merely be an extension of the authorized project for hurricane flood protection of Texas City and vicinity, Texas, currently under construction. Design criteria used in this study have been consistent throughout with those used for preconstruction design of the authorized project, which will afford full protection from a design storm with an expected recurrence interval of about 100 years. Accordingly, no tests were considered necessary to determine the economic effects of enlarging or reducing the scope of the project to afford varying degrees of protection and none were made.

82 I0 - - -

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-J TEXAS CITY AND VICINITY, TEXAS -J 0 (LA MARQUE-HITCHCOCK EXTENSION) 0 6 HURRICANE FLOOD PROTECTION 0 STAGE-DAMAGE RELATIONSHIP PLAN "C" 0 5 U.S. ARMY ENGINEER DISTRICT, GALVESTON, TEXAS DEC. 1965 -J -J TO ACCOMPANY REVIEW REPORT 2 4 FILE: GALV. 308-250 U) LW

0 18 16 14 12 10 8 6 4 ELEVATION IN FEET M.S.L.

EXHIBIT I APPENDIX II

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TEXAS CITY AND VICINITY,TEXAS (LA MARQUE-HITCHCOCK EXTENSION) W HURRICANE FLOOD PROTECTION '2 STAGE-FREQUENCY RELATION$HI P PLAN "C Z U.S.ARMY ENGINEER DISTRICT, GALVESTON, TEXAS DEC. 1965 0

S0TO ACCOMPANY REVIEW REPORT W W FILE: GALV. 308-250

8 EXISTING CONDITION

100 YEAR DESIGN

0 10 20 30 40 50 60 NO. OF TIMES EQUALED OR EXCEEDED IN 100 YEARS

EXHIBIT 2 APPENDIX II 84 9 '- -

6 $ I,000,00o x 10 $ 100,000 cr 100

-J-- 0 o AREA= LL 1$0,000,000 0 5

0 -J AVERAGE ANNUAL DAMAGES $ 266,300 RESIDUAL DAMAGES 40,300

4 TOTAL AVERAGE ANNUAL $ 226,000 DAMAGES PREVENTED ca

TEXAS CITY AND VICINITY, TEXAS (LA MARQUE-HITCHCOCK EXTENSION) 3 HURRICANE FLOOD PROTECTION DAMAGE-FREQUENCY RELATIONSHIP PLAN "C" U.S. ARMY ENGINEER DISTRICT, GALVESTON, TEXAS DEC. I965 2 TO ACCOMPANY REVIEW REPORT

FILE: GALV. 308 - 250

EXISTING DAMAGES

RESIDUAL DAMAGES

0 0 10 20 30 40 50 60 NO. OF TIMES EQUALED OR EXCEEDED IN 100 YEARS

EXHIBIT 3 APPENDIX II 85 86-965 0-67-7 s

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r REVIEW OF REPORTS ON TEXAS CITY AND VICINITY, TEXAS (LA MARQUE-HITCHCOCK EXTENSION) HURRICANE FOOD PROTECTION

APPENDIX III

ENGINEERING AND COST DATA

TABLE OF CONTENTS

Par - Title Page

2 General ------88 8 Design features and cost estimates ------91 11 Relocations ------91

12 Structures ------92 13 Annual charges ------92 14 Lands and rights-of-way ------92 15 Maintenance and operation ------92 16 Subsurface investigations ------93 18 Contingencies and allowances ------93 19 Preauthorization study costs ------93

TABLES

A Estimates of first costs for plans investigated------95 B Estimates of investments and annual charges for

plans investigated ------96 C Detailed estimates of first costs for plan of improvement - plan C ------97 D Consolidation of first costs, annual charges & annual benefits for plans investigated with those for Highland Bayou flood control project contained in House Doc. 168/89/1------99 E Pertinent data, plan of improvement (plan C)------100 F First costs, annual maintenance and operation costs, apportionment of cost among interests, and benefits to cost ratio for modified project ------102

EXHIBITS

l Location of borings 2 Soils profile and typical sections 3 Construction details 4 Aerial mosaic - Texas City and Vicinity, Texas 5 Aerial mosaic - Texas City and Vicinity, Texas

87 REVIEW OF REPORT ON TEXAS CITY AND VICINITY, TEXAS (LA MARQUE-HITCHCOCK EXTENSION) HURRICANE FLOOD PROTECTION

APPENDIX III ENGINEERING AND COST DATA

1. Scope.- This appendix presents engineering and cost data pertinent to studies to determine the advisability of extending the authorized Texas City and vicinity, Texas, hurricane flood protection project to encompass the unprotected portion of La Marque and the adjacent city of Hitchcock. Data presented in this appendix relate particularly to first costs, annual charges, subsurface conditions, rights-of- way and easement costs, construction costs, and maintenance and operation costs for the plans investigated.

2. General.= Tropical hurricanes that cross the Texas coast are accompanied by tides of up to 15 feet above mean sea level causing destruction to property in the study area by waves, currents, and inundation. The authorized Federal hurricane flood protection project for Texas City consists of about 16.2 miles of new and enlarged levees and about 1.3 miles of new floodwalls. The authorized flood control project for Highland Bayou, Texas, (House Document No. 168, 89th Congress, 1st Session), provides for protection from upstream flooding on Highland Bayou to the La Marque-Hitchcock area by improvement of the Highland Bayou channel, and by construction of a diversion dam and diversion channel following generally along Basford Bayou to Jones Bay.

3. The following five plans were given engineering and economic consideration for protecting the study area from damages caused by tidal flooding.

a. Plan A - Construct a levee on an alignment as shown on plate 3 with a pumping plant at Highland Bayou; gated drainage structures at Highland Bayou and the Basford Bayou diversion channel; rerouted to Greens Lake as described in paragraph 29 of the text of this report; and a navigation gate at Highland Bayou. Plan A would join the authorized Texas City project at the pumping plant near Interstate Highway 45 and the adjoining west leg of the authorized project would be eliminated.

b. Plan A-alternate - Construct a levee and appurtenant structures similar to plan A except divert the upper Highland Bayou runoff through an alternate channel to Karankawa Bayou in lieu of the Basford -Bayou diversion channel rerouted to Greens Lake. Plan A-alternate would join the authorized Texas City project at the pumping plant near Interstate Highway 45 and the adjoining west leg of the authorized project would be eliminated.

88 c. Plan B - Construct a levee on an alignment as shown on plate 3 with gated drainage structure at Wighland Bayou and the Basford Bayou diversion channel rerouted to Greens Lake, and a navigation gate at Highland Bayou. Plan B would join the authorized Texas City project near Interstate Highway 45 eliminating the pumping plant and adjoining west leg of the authorized project.

d. Plan C - Construct a levee on aia gnment as shown on plate 3 with a tide control and navigation structure and two gated tidal interchange structures in Jones Bayou. Plan C would join the authorized Texas City project near Interstate Highway 45 eliminating the pumping plant and adjoining west leg of the authorized project.

e. Plan D - Construct a levee on an alignment as shown on plate 3 with a tide control and navigation structure and two gated tidal interchange structures in Jones Bay. Plan D would join the authorized Texas City project near Texas Highway Loop 1970 Plan D would eliminate that portion of the authorized project from its intersection with plan D to its southwestern terminus.

4. Subsequent to initiation of the studies and general formulation of the above plans, a local developer announced plans and initiated construction of a large new subdivision, located such that the subdivision would be approximately bisected by the plan B alignment. With this development, ponding of interior drainage inside the levee area would not be practicable and large pumping costs would be involved. Additionally, the acquisition of rights-of-way and easements in that area would incur excessive costs, and a large part of the subdivision would be outside the protected area. Considering these problems and disadvantages, no further engineering and economic studies were made on plan B. The new subdivision described above includes a system of interconnecting canals to afford access for small boats to Galveston Bay. The diversion channel authorized in the Highland Bayou flood control project (H. Doc. 168/89/1) would bisect that system of canals and result in serious problems of maintenance of the canals due to increased silt loads carried by floodwaters from the upper Highland Bayou watershed. Consequently, the diversion channel alignment will be rerouted to Greens Lake south from the subdivision during preconstruction planning. Preliminary cost estimates of the proposed revised diversion channel show that there is no material increase in costs of the authorized Highland Bayou flood control project due to this revision. The two diversion alignments described above are shown on plate 3 of this report.

5. At this time, the alignment for plan C from mile 0 to about mile 2.1 is the most economical route for the construction of a levee under this plan. However, extensive highway interchange construction at the junction of highways Interstate 45, Texas 6, 3, and Loop 197 is in progress. The developers of Bayou Vista, located between Highland Bayou and Interstate Highway 45 and through which the levee alignment from mile 1.2 to about mile 1.3 would be located, have recently announced plans

89 86-965 0-67-8 for farther expansion of their existing canal-city resort-type area. It is conceivable that completion of the highway interchange, coupled with the proposed expansion of Bayou Vista, might result in rights-of-way and design problems such that it would be more practicable to modify the levee alignment in this reach. An alignment for plan C that would start at a point on the existing project immediately east from the Southern Pacific railroad, then follow along the easterly side of the Southern Pacific railroad to and on the alignment for plan D, then cross the Southern Pacific and Galveston-Houston & Henderson railroads, Interstate Highway 45, and the Gulf, Colorado & Santa Fe railroad to Jones Bay on the plan D alignment, would not have costs materially greater than those for the alignment presently shown. Numerous land developments similar to Flamingo Isles and Bayou Vista have been made, both in the immediate area and along the Texas coast in general, in the last 10 years. Plans for the development of Wilson Point in Jones Bay as Tiki Island have been recently announced. It is possible that other land promotional schemes are in planning stages and, for various reasons, release of information on such plans is being withheld. If alignment problems of the nature mentioned develop for plan C, modified alignments would be investigated during preconstruction planning. The contingency allowances provided in the cost estimate for plan C are believed adequate to cover the additional costs that might result from such revisions in the levee alignment.

6. Plan D was developed and investigated to determine whether cost savings could be attained with an alignment that would eliminate that portion of the authorized Texas City project from the pumping plant near Texas Highway Loop 197 to its southwestern terminus. It was found, however, that local interests had expended funds to acquire rights-of-way in the area between Texas Highway Loop 197 and Interstate Highway 45. Additionally, ramps were being constructed at Interstate Highway I45 that were designed to tie into the authorized Texas City hurricane flood protection levee. Since most of the expended funds could not be recovered if this reach of levee were rerouted, plan D was eliminated from further consideration.

7. In the survey report for the Highland Bayou flood control project, referred to in paragraph 2 of this appendix, the studies of stream flooding problems on Highland Bayou considered hurricane flooding only to the extent necessary to determine that the general plan of improvement would not be incompatible with future hurricane flood protection improvements for the western La Marque-Hitchcock area. The authorized plan for control of stream floods proposed enlarging Highland Bayou and constructing the Basford Bayou diversion channel to divert runoff from the upper Highland Bayou watershed. Plan A-alternate was developed and investigated to determine whether a more favorable overall plan of upstream flood protection combined with hurricane flood protection could be attained by diverting flows from the upper Highland Bayou watershed westward to Karankawa Bayou rather than eastward through the Basford Bayou diversion channel. It was found that the authorized Basford Bayou diversion channel, rerouted to Greens Lake as described in paragraph 29 of the text of this report,

90 affords the most economical plan for stream flood protection, and would be compatible with future hurricane flood protection improvements. An economic comparison of plans A, A-alternate, and C is shown in table D of this appendix. The most practicable plan was found to be plan C and is recommended for improvement.

89 Design features and cost estimates.- The design fe t s of the various plans investigated generally are identical or similar to those developed during post-authorization design of the authorized Texas City and vicinity project. The average costs of construction prevailing in the area in December 1965 were used in preparing the estimates of first costs for the plans investigated. The detailed estimates df first costs include the costs of lands and damages, relocations, construction, contingencies, engineering, design, supervision, and administration.

9. Generally, the levees proposed on land areas are designed with 1 on 6 side slopes on exterior sides; 1 on 3 side slopes on the interior sides; and 24-foot crown widths at elevations sufficient to prevent overtopping by the significant waves during passage of a design storm. The crowns would be sloped one foot from interior side to exterior side and surfaced with 9 inches of flexible pavement consisting of sand-shell base material with a double bituminous surface treatment to serve as a road. The levees would be constructed of compacted earth removed by land-based equipment from borrow areas adjacent to the levees. The resulting ditches would be used for collecting and carrying interior runoff to the ponding area. Levee side slopes would be provided with a turf of Bermuda grass for erosion protection. Where necessary in marsh areas 4 to 6 feet of soft material would be removed and wasted to reach suitable foundation soils. A typical section of this design is shown on exhibit 2 of this appendix.

10. The levees in the water area of the bay would be constructed by hydraulic dredge, allowed to settle for one year, and then reworked with land-based equipment to final shape. Side slopes would be protected from 5.0 feet below mean sea level to 5.0 feet above by 30 inches of riprap placed on 18 inches of filter material on the exterior sides and 18 inches of riprap on 9 inches of filter material on the interior sides, The side slopes above 5.0 feet elevation would be turfed and the crowns surfaced as described for land area levees. An overburden of soft clay material would be removed from the bay bottom to an average elevation of about -6.0 feet to reach suitable foundation soils. A typical section of this design is shown on exhibit 2 of this appendix.

11. Relocations.- One new railroad bridge would be constructed over the borrow ditch where the recommended levee crosses the Gulf, Colorado, and Santa Fe Railroad. The bridge would consist of an open deck frame trestle with 5-pile bents designed for E-65 loading. Pipeline and buried communication cable crossings would be encased in split steel pipe sleeves extending from exterior to interior toe of the levee with steel flanges provided at each end to reduce seepage along the outside of the pipes.

91 Power lines would be raised to code clearances required for the voltage rating and communication lines raised to a minimum of 18-foot clearance.

12. Structures.- Closure structures would be provided at the intersection of the recommended levee and Texas Highway 6 and the Gulf, Colorado and Santa Fe railroad. The structures would consist of concrete bays with welded steel swinging gates tied to adjoining levees by reinforced concrete walls. A tide control and navigation structure would be constructed in Jones Bay similar to the navigation structure developed for the authorized Texas City hurricane flood protection project. Two gated tidal interchange structures would be constructed through the recommended levees located to provide circulation in the portion of Jones Bay enclosed by the levee. Each tidal interchange structure would consist of three 3-foot high and 5-foot wide reinforced concrete box culverts, each culvert to have a steel slide gate closure. A tidal exchange channel would be dredged from the Gulf Intracoastal Waterway through the tide control and navigation structure into Jones Bay, and connecting channels be dredged from the tidal exchange channel to any existing private channels blocked by the levee. Dimensions of the access channels would be commensurate with those of the private channels, or of lesser size if not required for existing or foreseeable traffic.

13. Annual charges.- Estimates of interest and amortization of the initial investment included in the annual charges are based on 3.125 percent interest and an amortization period of 100 years. The annual charges also include the estimated annual costs for operation and maintenance.

14. Lands and rights-of-way. - Acquisition of rights-of-way would include lands required for the levee, appurtenant structures, and for alongside borrow areas. The estimated amounts of rights-of-way required for the various reaches of plan C are:

From : To :oAmount required Reach of levee: mile : mile : (acres )

Existing project to Texas Hwy 6 0 1.3 80 Texas Hwy 6 to GC& SF RR 1.3 2.5 101 GC & SF RR to Jones Bay 2.5 2.75 18 Across Jones Bay 2.8 6.2 0 Jones Bay to West terminus 6.2 11.4 339

15. Maintenance andoperation.- Maintenance of levees would entail maintaining a good turf, mowing, repairing erosion damage and replacing riprap, and repair to ramps and the road on top of the emba.nkment. Main- tenance of appurtenant structures would include periodic clearing of the modified Highland Bayou diversion channel, and lubrication of moving parts in the gated drainage and closure structures. Operation of the gated structures would be required periodically in addition to times of high tides, to prevent accumulation of sediment in the gate recesses. Main- tenance of the tidal exchange channel through the tide control and navigation structure would be performed as a part of the local cooperat ion and maintenance of thee entire hurricane flood protection project. Any maintenance or improvement of the channels required for navigation to the private developments within the enclosed area would be performed by the

92 Department of the Army permittees for the existing locally constructed channels. The estimated annual costs of operating and maintaining the various features of the recommended plan of improvement, and the amount that the annual operation and maintenance costs of the existing project would be decreased because of construction of the plan of improvement, are as follows:

Estimated annual costs Item : Maintenance : Operation : Total

Plan of improvement (plan C) Levees $25,000 0 $25,000 Modified diversion channel 3,000 0 3,000 Closure structures (2) 2,500 $2,500 5,000 Tidal interchange structures (2) 2,500 2,500 5,000 Tide control and navigation structure 10,000 7,000 17,000 Subtotals, annual costs for plan C 413000 2,000 55,000 Less credit for annual O&M costs for existing project eliminated by plan C -5,000 Additional annual 0&M costs to existing project by modification to include plan C $50,000

16. Subsurface investigations.- Auger borings and 3-inch Shelby tube undistrubed borings were made along several alignments and at other critical points to reveal the general foundation conditions. The location and logs of these borings are shown on exhibit 2 of this appendix.

17. The soils in the study area consist of the stiff to hard clays and sandy clays of the Beaumont Clay formation overlain by soft recent deposits in the marsh and bay areas. The firm to stiff clays provide an excellent material for constructing an impervious levee and are readily excavated by dragline and hydraulic dredge.

18. Contingencies and allowances. - The estimates include allowances to cover contingencies during construction, and the estimated engineering and overhead costs separated into engineering and design costs and supervision and administration costs. An allowance of 15 percent was used to cover contingencies in connection with the acquisition of lands, and a 20 percent allowance was used to cover contingencies in connection with relocations, dredging, and construction of the levee and appurtenant structures. The allowances for engineering and overhead costs were estimated on the basis of current costs in the district.

19. Reauthorization stud costs.- The sum of $53,000 has been expended for preauthorization survey and study costs including the preparation of this report. The cost estimates in this appendix are exclusive of the preauthorization study costs.

20. Tables presenting estimates of cost and annual charges are included in this appendix as follows.

a. Table A summarizes the cost estimates of the three investigated plans of improvement. 93 b. Table B presents estimates of the investments and annual charges for the three p ns investigated.

c. Table C presents detailed estimates of first cost for- the plan of improvement (plan C).

d. Table D combines first costs, annual charges, and annual benefits for the plans investigated with those for the Highland Bayou flood control project contained in H.D. 168/89/1.

e. Table E presents estimates of cost for the individual work items included in the plan of improvement (plan C), and for the work items in the existing project that would be eliminated by the plan of improvement (plan C).

f. Table f combines first costs, annual charges, and annual maintenance and operation costs of, the plan of improvement (plan C) with those of the existing project, and presents the apportionment of costs among interests and the benefits to costs ratio for the modified project.

94 TABLE A

ESTIMATES OF FIRST COSTS FOR PLANS INVESTIGATED (December 1965 prices)

Item : Plan A : Plan A-alt : Plan C

01.0 Lands and damages $1, 583,000 $2, 325,000 $510,000 02.0 Relocations 540,000 540,000 206,000 09,0 Channels 1,65.1,000 0 98,000 10.0 Seawalls 3,153,000 3,121,000 14,636,000 13.0 Pumping plants 5,160,000 6,791,000 0 30.0 Engineering and design 936,000 941,000 1,350,000 31.0 Supervision and administration 977,000 982,000 1,420,000 Subtotals, first cost for investigated plans 14,000,000 14,700,000 18, 220,000

Less credit for eliminated portions of authorized project 1,600,000 2/ 1,600,000 g/ 2,520,000 3

Additional cost to authorized project by modification to include investigated plans 12,400,000 13,100,000 15, 700, 000

Additional cost for Karankawa B. diversion channel in lieu of Basford B. diversion channel 1,150,000 31

Total f or plan A alternate 14, 250,000

JrllehNY4T SWtR1 lMMR bl + !tw l' x +'n ] M iR t.R [1n M !YlMvtJfi MW

f/ Recommended plan

2/ Lands and damages $255,000 Relocations 335,000 Seawall 1,012, 000 1,602,000

Use 1,600,000

3/ item g/ above cost $1, 602,000 Pumping plant 918,000 2,520,000

3/ From table A, appendix III, Interim report on Highland Bayou, Texas, dated August 5, 1963, H. Doc. 168/89/1.

95 TABLE B

ESTIMATES OF INVESTMENTS AND ANNUAL CHARGES FOR PLANS INVESTIGATED

(Construction period - 48 months) (Interest rate - 3.125%) (Amortization period - 100 years) (Prices as of December 1965)

Item : Plan A : Plan A-alt : Plan C

Total first cost $12,400,000 $13,100,000 / $15,700,000

Federal investment Federal first cost (70% of total) 8,680,ooo 9,170,000 10,990,000 Interest during construction 543,000 573,000 686,800 Total Federal investment 9,223,000 9,743,00 11,676,800

Non-Federal investment Non-Federal first cost (30% of total) 3,720,000 3,930,000 4,710,000 Interest during construction 233,000 246,000 294,400 Total non-Federal investment 3,953,000 176,000 5,004,400

Federal annual charges Interest on Federal investment 288,000 304, 000 365,000 Amortization of Federal investment 14,000 15,000 18,000 Maintenance and operation None None None Total Federal annual charges 302,000 319,00033,000

Non-Federal annual charges Interest on non-Federal investment 124,000 131,000 156,400 Amortization of non-Federal investment 6,ooo 6,000 7,600 Maintenance and operation 42,000 40,000 50,000 Total non-Federal annual charges 172,000 177,000 214,000

Total annual charges 474,000 496,000 597,000

l Investment and annual charges for incremental cost of $1,150,000 for Karankawa Bayou diversion over Basford Bayou diversion (last item, table A of this appendix) are included in amounts for the Highland Bayou flood control project (second consolidation of first costs, annual charges and annual benefits, table D of this appendix)*

96 TABLE C

DETAILED ESTIMATES OF FIRST COSTS FOR PLAN OF IMPROVEMENT (December 1965 prices)

(PLAN C)

Unit :o Unit Item :quantity: cost : Q ntity Cost

(03.0) Lands and damages (a) Rightsof way Acre $i,600.oo 80 128,000 Acre 1,200.00 101 121,000 Acre 500.00 18 9,000 Acre 400.00 339 135,600 (b) Acquisition costs Tract 1,000.00 50 50,000 Subtotal, lands and damages Contingencies, 15% 66, 400 Total, lands and damages 510,9000

(0200) Relocations (a).Road ramp L.S. 3,040 (b) 2-30" waterlines L.F. 3,000 120,000 (c) Power distribution line L.S. 1,020 (d) Telephone line at Highway 6 L .F 0 0.18 750 135 (e) Telephone lines at G0 C0 & S.F. R L.S. 2,600 (f) Signal wires, G.C. & S.F. R L.S. 450 (g) Shoo-fly at G.C. & S.F. RR L.S. 20,600 (h) Railroad bridge (G.C. & S.F. R) L.F. 125.000 180 22,500 Subtotal, relocations 17®7735 Contingencies, 20%+ 35-,655 Total, relocations 206,000

(09.0) Channels (a ) Tidal exchange & connecting channels in Jones Bay C.Y. 0020 410,000 82,000

Contingencies, 20% 16 000 Total, channels 9 9000

(l00) Seawalls (a) Compacted embankment C.Y. 0.52 7,400,000 3,848,000 (b) Hydraulically placed embankment C.Y. 0.50 7,100,000 3,550,000 (c) Stripping and waste excavation C Y. 0.19 3,050,000' 579; 500 (d) Turf irg Acre 500000 488 244,000

97 TABLE C (Cont'd)

Unit Unit Item :quantity, eQst : Quantity: Cost

(10.0) Seawalls (Cont'd) (e) Riprap side slope$ Ton $7.00 134V,000 $938,000 (rf) Filter Ton 5.25 76,000 399,000 (g) Levee crown L.S. 529,500 (h) Closure structure at State Highway 6 L.S. 270,000 (i) Closure structure at G.C. & S.F. RR L.S. 50,000 (j) Tide control and navigation structure L.S. 1,590,000 (k) Tidal interchange structures Each 108,000.00 2 216 000 Subtotal, seawalls 12, 21.,000 Contingencies, 20% 2 42200 Total, seawalls is 3000

(30.0) Engineering and design 1,350,000

(31.0) Supervision and administration 1,420,000

Total cost for plan of improvement (plan C) 18,220,000

98 TABLE D

CONSOLIDATION OF FIRST COSTS, ANNUAL CHARGES & ANNUAL BENEFITS FOR PLANS INVESTIGATED WITH THOSE FOR HIGHLAND BAYOU FLOOD CONTROL PROJECT CONTAINED IN H. DOC. 168/89/1

Highland B., Basford B. Combined Item Plan A Div. Chan. projects First costs $12, 400,000 $4,870, 000 $17,270,000 2/ Annual charges 474,000 196,000 670,000 Annual benefits 376,000 696,000)2/ 1,072,000 Benefits to costs ratio 0.8 3.6 ) 1.6

Highland B., Karankawa Combined Item Plan A-alt B. Div. Chan. projects

First costs $13,100,000 3/ $6,020,000 3/ $19,120,000 i/ Annual charges 496,000 236,000 732; 000 Annual benefits 376,000 637,000 1,013,000 Benefits to costs ratio 0.8 2.7 1.4

Highland B., Basford B. Combined Item Plan C Div. Chan. fro jec t

First cost $15, 700,000 $4,870, 000 $20,570,000 V Annual charges 597,000 196,000 793,000 Annual benef its 866,ooo 696,000 1, 562,000 Benefits to costs ratio 1.4 3.6 2.0

2/ Price levels: HD 168/89/1, August 1963 This report, December 1965

2/ Benefits and benefits to costs ratio as revised by Bureau of the Budget.

3/ Incremental cost of $1,150,000 for Karankawa Bayou diversion over Basford Bayou diversion (last item, table A of this appendix) is included in $6,020,000 amount for flood control plan, Highland Bayou, Karankawa Bayou diversion channel.

99 TABLE E

PERTINENT DATA

PLAN OF IMPROVEMENT (PLAN C)

Feature Work Item Estimated cost, / Lands and R-.0-W, 538 Ac 510,000 damages

Relocations Road ramp, private road, levee mil 1103 4,600 Two 30" waterlines, levee miles 1U.3 & 2,5 180, 500 12 KV powerline, levee mi. 1.3 1,500 Telephone line @ Hwy 6, levee mi. 1.3 200 Telephone line @ GC&SF RR, levee mi. 2.05 3,900 GC&SF RR bridge, shoo-fly, & signal wires, levee mi. 2.5 65, 300 256,000

Channels 12' x 100' x 1,500' tidal exchange channel, & 10' x 100' connecting channel to existing private channels 116,000

Seawalls 11. 4 mi. earth levee; crown elev. +21.0' MSL mi. 0 to .i. 10.0, +21.0' to +16.0' from ml. 10.0 to 11.2, +16.0' to +15.0' from mi. 11.2 to 11.4; bituminous surfaced crown 24' wide throughout; side slopes 1 on 10 in bay area, 1 on 6 on land; riprap side slope protection to +5.0 elev. in bay area, turfed slope above to crown; turfed side slopes on land reaches 14, 320,000 Closure structure @ Hwy 6, levee mi. 1.3 383,000 Closure structure @ GC&SF RR, levee mi. 2.5 71,000 Tide control & navigation structure, levee mi. 5.2 2,257,000 Tidal interchange structures, levee miles 3.2 & 3.8.307.000 17, 338,000

Total cost - plan C 18,220,000

100 TABLE E (Cont'd)

Portion of authorized project eliminated by Plan C (from Texas City Terminal Railway to West End of Levee, Sta. 802+00 to Sta. 927+58)

Feature Work item Estimated cost 2/

Lands and Levee R-0-W, 119.9 Ac $215,000 damages Severance damages 40,000 255,000

Relocations Bayou Road, bridge and ramp 30,000 Lake Road, ramp and culvert 10,000 Texas City Term Ry, trestle aid temp. support during construction of closure structure x0,000 Utilities 255,000 335,000

Seawall 2.38 mi. earth levee 902,000 Closure structure, Texas City Term Ry 54,000 Gravity drainage structures 56,000 1,012,000

Pumping La Marque pump station 918,000 plant

Total cost of portion of authorized project deleted by plan C 2, 520,000

Additional cost to authorized project by modification to include plan C 15,700,000

2/ Includes contingency allowances and costs for engineering, design, supervision and administration.

101 TABLE F

FIRST COSTS, ANNUAL MAINTENANCE AND OPERATION COSTS, APPORTIONMENT OF COST AI)NG INTERESTS, AND BENEFITS TO COSTS RATIO FOR MODIFIED PROJECT

EXISTING PROJECT :Project cost : First costs : Remaining estimate :eliminated by project Item : (Aug 1965) Plan C 0 costs

010 Lands and damages $1,977,000 $255, 000 $1,722,000 02. Relocations 474,000 290,000 184,000 11. Levees and floodwalls 15, 234,000 876,000 14, 358,000 130 Pumping plants 1,790,000 790,000 1,000,000 300 Engineering and design 2,300,000 159,000 2,141,000 310 Supervision and administration 8 25,000 150,000 675, 000 Totals, existing project 22, 000, J 2,520,000 $20,. 60-0,000

Federal share 15,700,000?/ 1,764,000(70%) 13,936,000 Non-Federal share 6,900,0003/ 756,000(30%) 6,144,000

Includes $171,400 local interests costs for ramps in lieu of closure structures. 2 70% of $22,428,600 = $15,700,000 3/ 30% of $22,428,600 = $ 6,728,600 + 171,400 $6,900,000 PLAN OF IMPROVEMENT (PLAN C) Item Project cost estimate

01. Lands and damages $510, 000 02. Relocations 206,000 090 Channels 98,000 100 Levees and floodwalls 14,636,000 30. Engineering and design 1, 350,000 31. Supervision and administration 1,420,000 Total cost to be apportioned $18, 220,000 Less credit for items of existing project eliminated 02, 520,000 Additional cost to existing project by modification to include plan of improvement (plan C) $15,700,000 Federal share of apportioned cost (70%) 12,754,000 Non-Federal share of apportioned cost (30%) 5, 466,000 MODIFIED PROJECT : Federal Non-Federal 4 Total Item_ __share of costs:Qshare of costs : costs

Remaining costs for existing project $13,936,000 $6, 144,000 $2o,080, 000 Plan of improvement (plan C) 12,75 ,000 5 466,000 i8,2 00 Totals $2 6,90,000 $P. 610,000 $38, 00so000

102 TABLE F (Cont'd) Recapitulation:

Project cost estimate, existing project (July 65) $22, 600, 000 Additional cost to existing project by modification to include plan of improvement (plan C) 15,700,000 Total cost of modified project 38,300,000 APPORTIONMENT OF FIRST COSTS & ANNUAL MAINTENANCE AMhD1 INTERESTS

Item Federal :Non-Federal Total

Existing project First cost Construction $15, 646,000 $4,8o5, 600 $20, 451,6oo Lands 54,OOO/ 1,923,000 1,977,000 Ramps None 171,400 171 400 Subtotal, first cost existing project $15,700,000 $6,900,ooo 22, ooooo Annual cost of maintenance & operation None $55,000 Plan of improvement (plan C) First cost Construction $10,980,000 $4 ,004, 000 $24, 984,000 Land 10,0oo00/ 500, 000 510,000 Relocations None 2o6,000 206,000 Rubeotai,first cost plan of improvement $10,990,000 $4,710,000 $15,700,000 Annual cost of maintenance & operation None $50,000 $50,000

Modified project First cost Construction $26,626,000 $8,809,600 $35,435,60o Land 64,ooo/ 2,423,000 2,487,000 Ramps None 171,400 171,400 Relocations None 206,000 206,000 Total first costs, modified project $26,690,000 $1160,000 $3,300, 000

Annual cost of maintenance & operation None -:o5 ,000 $105,000 V Legal review onlyo. Comparison of benefits and costs

Plan of Existing Improvement Modified

project (plan C) p~r oject Average annual benefits $1, 989,000 $866,000 $2,855,000 Annual charges 726,000 597,000 1,323,000 Ratio of benefits to charges 2.7 1.4 2.1

103

REVIEW OF REPORT ON TEXAS CITY AND VICINITY, TEXAS (LA MARQUE-HITCHCOCK EXENSION) HURRICANE FLOOD PROTECTION

APPENDIX IV

CONTENTS BY OTHER AGENCIES

TABLE OF CONTENTS

Title Page

Introduction ------106

U. S. Fish and Wildlife Service letter report dated October 20, 1964 with inclosed copy of letter from Texas Parks and Wildlife Department dated September 25, 1961- 107

County of Galveston letter dated June 23, 1965 with inclosed resolution of the Commissioners Court of Galveston County,

Texas, executed June 21, 1965 ------112

U. S. Bureau of Mines letter dated September 1, 1965 ------116

U. S. Soil Conservation Service letter dated September 3, 1965- 117

U. S. Fish and Wildlife Service letter dated September 13, 1965- 118

Department of Health, Education and Welfare letter data. September 13, 1965 ------119

105 86-965 0-67-9 REVIEW OF REPORT ON TEXAS CITY AND VICINITIY, TEXAS (LA MARQUE-HITCHCOCK EXTENSION) HURRICANE FLOOD PROTECTION

APPENDIX IV

COMMENTS BY OTHER AGENCIES

INTRODUCTION

In accordance with the Interagency Agreement on Coordination of Water and Related Land Resources Activities approved by the President on May 26, 1954, draft copies of the main report and appendixes were sent to other Federal agencies at field level for review. Letters from the agencies containing their comments and replies where appropriate are presented in this appendix.

106 UNITED STATES DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE SERVICE BUREAU OF SPORT FISHERIES AND WILDLIFE POST OFFICE BOX 1306 ALBUQUERQUE, NEW MEXICO 87103

October 20, 1964

District Engineer Corps of Engineers, U. S. Army Post Office Box 1229 Galveston, Texas

Dear Sir:

This letter constitutes the report of the Bureau of Sport Fisheries and Wildlife on fish and wildlife resources to be affected by the proposed Hitchcock Extension of the Hurricane Flood Protection Project for Texas City and Vicinity, Galveston County, Texas. Our report has been prepared under the authority of and in accordance with the provisions of the Fish and Wildlife Coordination Act (48 Stat. 401, as amended; 16 U.S.C. 661 et seq.). It has been coordinated with the Bureau of Commercial Fisheries and has received concurrence of the Texas Parks and Wildlife Department by letter dated September 25, 1964, signed by Mr. J. Weldon Watson, Executive Director. A copy of that letter is enclosed.

The Bureau of Sport Fisheries and Wildlife issued a letter type report on the authorized Hurricane Protection Project for Texas City and Vicinity on March 31, 1960. On May 17, 1963, the Bureau issued a letter type report on Brazoria-Galveston Soil Conservation District, Highland Bayou Project, Texas. The latter report concerned proposed developments to provide flood protection in the vicinity of Alta Loma, Camp Wallace, La Marque, and Hitchcock; channel improvements on High- land and Basford Bayous; and a diversion dam and channel on Highland Bayou.

The project considered herein will provide flood protection from hurricane storm tides to Hitchcock, the western portion of La Marque, and to existing and proposed residential and industrial sites lying south of U. S. Highway No. 75 and flanking Basford and Highland Bayous.

The project will consist of a ll.4-mile-long earthen levee, the top of which will be 21 feet above mean sea level on those sections travers- ing Jones Bay, tapering to 18 feet on those sections lying on land. The levee will tie into the southernmost point of the levee authorized in

107 the Texas City and Vicinity Hurricane Flood Protection Project, and will parallel U. S. Highway No. 75 to a point about 1 mile southeast of its junction with State Highway No. 6. From this point, the levee will extend south across Jones Bay crossing the western tip of Wilson Point to the Gulf Intracoastal Waterway near mile 366; then in a west- northwesterly direction for about 5.5 miles, where it will toe into higher ground at about elevation 15. There will be a 50-foot navigation opening with a guillotine-type gate near the Gulf Intracoastal Waterway adjacent to the spoil banks nearest to the mouth of Basford Bayou. Other gated openings will be located in the bay sections of the levee to provide for water exchange. The exact sizes and locations of these openings are not yet known.

The area of influence for fish and wildlife consists of about 2,000 acres of Jones Bay, the lower portions of Highland and Basford Bayous, and those lands lying between the proposed levee and the estimated contour of the limit of historical storm tide intrusion. These lands lie generally south of the Santa Fe Railroad tracks and encompass several thousand acres of heavily grazed salt meadows and shallow freshwater marshes.

Highland and Basford Bayous drain into Jones Bay. Flows in.the upper reaches of both streams are intermittent except when carrying return flows from irrigation of ricelands. The lower reaches of the streams are tidal. Freshwater fish habitat of minor importance occurs in portions of the streams. At present, public access to Basford Bayou is limited. Residences, industries, and marinas are being developed along the lower reaches of both streams. More of such development is anticipated in the future.

Jones Bay is a shallow, brackish arm of West Bay. It is an important breeding, feeding, and nursery area for fish and shellfish. The tidal reaches of Basford and Highland Bayous also serve as nursery areas and provide for egress of nutrients from the marshes. Important fish and shellfish are spotted seatrout, red drum, flounders, black drum, blue crabs, menhaden, and shrimp. Jones Bay contributes significantly to the sport and commercial fishery of the Galveston Bay estuarine system and associated offshore waters. Because of its location near large concentrations of people, the bay is fished heavily by sportsmen. In the future without the project, sport fishing would amount to about 32,000 man-days annually. The annual contribution of the bay to the commercial fishery harvest would be an estimated 1 million pounds.

108 The project will have no appreciable effect upon freshwater fish habitat in the bayous of the area. However, the effect upon the Jones Bay estuary is expected to be profound and extremely detrimental.

The major portion of Jones Bay will be effectively isolated from the remainder of West Bay by the levee. Thus, its sport and commercial fishery, as well as its contribution as nursery breeding and foraging grounds for West Bay will be lost. Moreover, water circulation in that portion of Jones Bay lying east of the levee will be curtailed. (The expected increase in agriCultural, industrial, and domestic pollution entering the bay via Basford and Highland Bayous will accumulate in the enclosed bay.) The only connection of this portion of Jones Bay wiTh West Bay will be the narrow opening lying just south of the west end of the Galveston Causeway. While water-exchange openings will be provided in the levee, it is highly unlikely that a sufficient number of openings can be provided for adequate circulation of water and nutrients and still give effective hurricane protection.

Wildlife in the area includes bobwhites, mourning doves, cottontails, squirrels, muskrats, minks, raccoons, opossums, snipes, woodcocks, and a few clapper rails, coots, ducks, and geese. The heavily grazed meadows and marshes are of low value to waterfowl, fur animals, and upland game. There is some waterfowl hunting, but trapping of fur animals and hunting for other wildlife is insignificant. Wildlife habitat is being depleted rapidly by urban and industrial developments. However, the project is not expected to affect wildlife resources.

To avoid loss of the valuable fishery resources of Jones Bay, the levee should be placed on land. Fish and wildlife recources would not be damaged by a levee along the shoreline of Jones Bay and West Bay. Openings should be provided in the shoreline levee at the mouths of all major streams to allow small -boat navigation and to provide for pollution diffusion and nutrient outflow.

It is recommended:

1. That the levee be placed on shore, with openings at the mouths of all major streams to allow for small- boat navigation, egress of nutrients, and diffusion of pollutants.

109 We appreciate the opportunity extended to us to comment on this development. Our report is based upon project data received from your agency prior to May 21, 1964.

Sincerely yours,

Carey H. Bennett Acting Regional Director

Enclosure

Copies (10)

Distribution:

(4) Executive Director, Texas Parks and Wildlife Department, Austin, Texas (2) Regional Director, Bureau of Commercial Fisheries,. Region 2, St. Petersburg Beach, Florida (2) Laboratory Director, Biological Laboratory, Bureau of Commercial Fisheries, Galveston, Texas (1) Regional Coordinator, Southwest Field Committee, USDI, Muskogee, Oklahoma (1) Area Director, Bureau of Mines, Area 4, Bartlesville, Oklahoma (2) Field Supervisor, Branch of River Basin Studies, Bureau of Sport Fisheries and Wildlife, Fort Worth, Texas

110 PARKS AND WILDLIFE DEPARTMENT

. W .,®W A" C O M M I SS I O NE R SJ .o~'j ®o ®".J. WEI-DON WATSON

WILL E. ODOM EXECUTIVE DIRECTOR CHAIRMAN, AUSTIN

A. W. MOURSUND MEMBER. JOHNSON CITY JAMES M. DELLINGER *e S MEMBER, CORPUS CHRISTI **

JOHN H. REAGAN BUILDING AUSTIN, TEXAS 78701 September 25, 1964

Regional Director U. S. Fish and Wildlife Service Post Office Box 1306 Albuquerque, New Mexico

Attention Carey H. Bennett

Dear Sir:

Reference is made to the draft of your proposed report concerning Hitchcock Extension of the Hurricane Flood Protec- tion Project for Texas City and Vicinity, Galveston County, Texas.

We have reviewed and are in concurrence with the findings of this report.

Sincerely yours,

J. Weldon Watson

JWW:TRL:sfb CC: Mr. John Degani Mr. Jim Stevens

111 4 t

C INTY COMMISS IONERS COURT COUNTY "OFFICIALS P.. .R J. LA VALLE V. J. BENINATI, JR. COUNTY JUDGE t - rei DISTRICT CLERK IRWIN P. DANTIN JULES DAMIANI, JR. FIRST PRECINCT CRIMINAL DISTRICT JIMMIE VACEK ATTORNEY Ga:COND PRECINCT C.' R. JOHNSON, ASSESSOR PAUL HOPKINS THE COUNTY OF GALVESTON AND COLLECTOR OF THIRD PRECNCT TAXE. JACK LAWRENCE HUDSON J. CAROSR. FOURTH PRECINCT GALVESTON, TEXAS COUNTY AUDITOR GERTRUDE MCKENNA TROY O. JOHN COUNTY CLERK COUNTY TREASURER June 23, 1965 VIRGIL D. SCHULTZ COUNTY ENGINEER J. B. KLINE, SHERIFF PAUL A. MILLIGAN COUNTY SURVEYOR HUGH GIBSON, JR., JUDGE COUNTY COURT NO. 2

Colonel John Unverferth District Engineer U. S. Army Engineers District, Galveston Corps of Engineers 606 Santa Fe Building Galveston, Texas

Re: Proposed westward Extension Texas City-La Marque Hurricane-Flood Protection Project

Dear Colonel Unverferth:

Enclosed herewith are six copies of the resolution assuring the Federal Govern- ment that the County of Galveston will act as local sponsor for the proposed westward extension of the Texas City-La Marque Hurricane-Flood Protection Project, upon the conditions set out in such resolution.

Yours very truly,

PETER J. LA VALLE County Judge Galveston County, Texas

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112 T HE STATE OF TEXAS

COUNTY OF GALVESTON

BE IT REMEMBERED THAT on the 14th day of June, 1965, the Commissioners

Court of Galveston County, Texas, convened in Special session with the following members thereof present:

Peter J. La Valle, County Judge Irwin P. Dantin, Commissioner Precinct No. 1 Jimmie Vacek, Commissioner Precinct No. 2 Paul Hopkins, Commissioner Precinct No. 3 Jad< Lawrence, Commissioner Precinct No. 4 and Gertrude McKenna, County Clerk when the following proceedings, among others, were had, to-wit:

WHEREAS, on January 8, 1963, the Commissioners Court of Galveston County,

Teas, requested the United States Army Engineers District, Galveston, Corps of

Engineers, to make a survey of the feasibility of extending the Hurricane-Flood

Protection Project for Texas City-La Marque, Texas, to include the western portion of

La Marque and Hitchcock to protect life and property of persons in that area and for the future growth of Galveston County; and

WHEREAS, the aforesaid District has completed such a survey and has found this etension feasible and will so recommend in its report to the Chief of Engineers, but requires a local sponsor for this improvement before so recommending;

NOW THEREFORE BE IT RESOLVED that the County of Galveston respectfully agrees to act as local sponsor for the proposed extension of the Hurricane-Flood

Protection Project westward from U. S. Highway 75 to protect the western portion of the County including the West La Marque and Hitchcock areas upon the following conditions: 113 1. That the Corps of Engineers continue to construct to the full extent of their capabilities, and on a schedule as originally planned and approved, all remaining portions of the Project eastward of U. S. Highway 75, save and except the pumping plant located at station 795 + 15 in La Marque.

2. That the County of Galveston will acquire the right-of-way and build, at its own expense, approximately two and one-half miles of levee from station

795+ 15 rnorrwc.rc. and parallel to U. S. Highway 75 to the 15 foot contour at station 927 ,- 58 to form a complete closure to protect for the time being the 55,000

:ersons and property in the original 40 square miles Texas City-La Marque area, whale extension plans go forward.;

3. That if a local bond issue for the Project extension should be submitted and

fail, the authorization for the Texas City-La Marque Hurriaone-Flood Prote:tion

Project will revert back to its present authorized status with the Corps of Engineers

to obtain funds to construct the La Marque pumping plant at station 795 + i5 and

rebuild the two and one-half miles of levee to be constructed by the County as

originally planned without the aforesaid District's being required to make resurveys

or reports, in order to avoid undue delay in completing the presently authorized

Project, and the County is to receive credit for its previous expenditure as part of

its 30% contribution;

4. That every effort will be made. to see that the presently approved Project

east of U. S. Highway 75 and the substitute section of levee to be built solely

10 the County is completed by the present schedule of mid-year 1967.

114 UPON MOTION of Commissioner Hopkins, seconded by Commissioner Dantin, the above Resolution was passed, Commissioner Jack Lawrence obstaining.

EXECUTED THIS the 21st day of J ue, 1965. ".

Peter J. La, alle, County Judge

IrwinP. Dantin, Commissioner Precinct 1

Im. 'Vacek, Commissioner Precinct #2

Paul Hopkins, Commis oner Precinct f3

Jack Lawrence, Commissioner Precinct #4 ATTEST:

Gertrude McKenna, Cournty Clerk

115 oTt}O .UNITEDSTATES .

- DEPARTMENT OF THE INTERIOR BUREAU OF MINES

AREA IV ROOM 204 FEDERAL BUILDING Office of Mineral Resource Office BARTLESVILLE, OKLAHOMA 74004 AREA DIRECTOR

September 1, 1965

Mr. T. W. Elam Chief, Engineering Division U.S. Army Engineer District, Galveston P.O. Box 1229 Galveston, Texas 77551 Reference: SWGGW-2c Dear Mr. Elam:

Thank you for sending us a draft copy of hurricane flood protection survey report on Texas City and vicinity, Texas (La Marque-Hitchcock extension) for field level review.

The proposed works of improvement to extend protection to the presently unprotected portion of La Marque and the adjacent city of Hitchcock would provide for a southward and westward extension of earthen levees and appurtenant structures. The ratio of average annual benefits ($866,000) to average annual cost ($597,000) is 1.4 to 1.0.

The Area IV Mineral Resource Office of the Bureau of Mines is in favor of the proposed works of improvement; they will provide needed protection to petroleum refineries, petrochemical plants, tin. smelter and other mineral industry plants in the area. No field examination was made, but the Area Director and members of his staff are well acquainted with Texas City and the vicinity covered by the report.

Sincerely yours,

Robert S. Sanford Area Director

116 UNITED STATES DEPARTMENT OF AGRICULTURE SOIL CONSERVATION SERVICE P. 0. Box 648 Temple, Texas 76502

September 3, 1965

Mr. T. W. Elam Chief, Engineering Division Corps of Engineers, U. S. Army 606 Santa Fe Building Galveston, Texas

Dear Mr . Elam:

We appreciate the opportunity to review the draft of the hurricane flood protection survey report on Texas City and vicinity, Texas (La Marque-Hitchcock extension).

The Soil Conservation Service has no projects planned in the area involved, and has no comments to make concerning the proposed project.

As requested, we are returning the draft copy of the report.

Sincerely yours,

A' N. Smith State Conservationist

117 NOpr UNITED STATES DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE SERVICE BUREAU OF SPORT FISHERIES AND WILDLIFE ,16vc POST OFFICE BOX 1306 ALBUQUERQUE, NEW MEXICO 87103

September,13, 1965

AIRMAIL District Engineer Corps of Engineers, U. S. Army Post Off-ice Box 1229 Galveston, Texas

Dear Sir:

The draft of your Review of Report on Texas City and Vicinity, Texas (La Marque-Hitchcock Extension), which was transmitted by Mr. T. W. Elam's -letter of August 26, 1965, has.been reviewed. We are pleased to note that this Bureau's report of October 20, 1964, is included in Appendix IV.

It is noted that the recommendation of the Bureau of Sport Fisheries and Wildlife has been considered carefully by your office and a plan has been devised to reduce the deterimental effects of the project on fish habitat. We appreciate these considerations and are of the opin- ion that most of the fishery losses envisioned in our report of Octo- ber 20, 1964, will be offset by the measures contemplated.

The opportunity extended to us to comment on the draft of the report is appreciated. As requested by Mr. Elam, we enclose the copy of the draft of the report for return to your office.

Sincerely yours,

Lewis R. Garlick Assistant Regional Director Cooperative Services cc: Executive Director, Texas Parks and Wildlife Department, Austin, Texas Laboratory Director, Biological Laboratory, BCF, Galveston, Texas Field Supervisor, Division of River Basin Studies, Bureau of Sport Fisheries and Wildlife, Fort Worth, Texas

118 pa l DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE REGIONAL OFFICE 1114 Commerce Street Dallas, Texas 75202

PUBLIC HEALTH SERVICE September 13, 1965

Your reference: SWGGW-2c District Engineer U. S. Army Engineer District, Galveston Corps of Engineers P. 0. Box 1229 Galveston, Texas 77551

Dear Sir:

We have had an opportunity to review the advance copy of your "Review of Report on Texas City and Vicinity, Texas (La Marque-Hitchcock Extension)" recently furnished us.

We find that, in general, the project will benefit public health in the area generally by reducing flooding and hazards during times of hurricane. Also, the channel improvements on Highland Bayou should promote drainage of low areas eliminating mosquito breeding locations.

However, the restriction of flow to and from Jones Bay produced by the construction of the levee proposed in Plan C may result in a highly unsatisfactory water quality condition in the area behind the levee. Highland Bayou receives the treated effluent from several municipal waste treatment plants. Jones Bay is located in a part of West Bay classified by the Texas State Department of Health as an insanitary area, thus, restricting the harvesting of oysters.

We are forwarding the draft to our Communicable Disease Center for review with respect to vector mosquito control requirements. Their comments will be sent on to you when received together with the draft copy.

We appreciate the opportunity to review this report.

Sincerely yours,

JtROME H. SVORE Regional Program Director Water Supply & Pollution Control cc: Texas Water Pollution Control Board Texas State Department of Health

119 REVIEW OF REPORT ON TEXAS CITY AND VICINITY, TEXAS (LA MARQUE TCIOCK EXTENSION) HURRICANE FLOOD PROTECTION

INFORMATION CALLED FOR BY SENATE RESOLUTION 148, 85TH CONGRESS ADOPTED JANUARY 28, 1958

1 Authority The following information is furnished in response to Senate Resolution 148, 85th Congress, adopted January 28, 1958,

2. Requests by local interests.- At a public hearing held in Hitchcock, Texas, on January 8, 1963, the Galveston County Commissioners Court requested extending the authorized Texas City hurricane flood protection project to include similar protection to portions of western La Marque and the adjoining city of Hitchcock.

3. Improvements considered.- A plan of improvement that would afford flood protection from all storms as large as the design hurricane, which has an expected recurrence interval of about 100 years, was found justified and is recommended for authorization and construction. This is essentially the improvement desired by local interests and affords the same degree of protection to the additional area as that afforded to Texas City and vicinity by the presently authorized protection project. Economic analyses for the plan of improvement were made only on a basis of a 100-year project life.

4. The improvements proposed under the recommended plan of improvement have been discussed with the local interests that would be responsible for providing the local cooperation required for the improvements if, and when, adopted. They have expressed satisfaction with the recommended plan of improvement. 0

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