2010 Charter Amendment

Text of the original dedicated drainage and street improvement proposal.

Texas Supreme Court 2015-13-0047

Found that ballot language for the 2010 proposal was misleading because it didn’t mention that the dedicated fund would be paid for by a new tax on residents. The Supremes remanded the case back to a trial court for disposition.

Final Summary Judgment of Trial Court

Declared the 2010 election null and void as if it had never happened. Ordered a new election.

2018 Proposition A Language

Identical to 2010 language with the exception of one word. In B(iii), the word “equal” in 2010 has been changed to “equivalent” here. Note also that the Supreme Court’s concern about the ballot language has been addressed separately toward the end of the amendment language.

Summary of Issues

Bob Rehak’s post that attempts to clear the fog. Explains why we’re voting again and what the consequences are.

Professional Liability for Construction in Flood Hazard Areas

A legal paper from the Association of State Flood Plain Managers. It addresses the liability of architects, engineers, landscape architects, surveyors, floodplain managers and other professionals in designing or constructing structures that are subsequently damaged by flooding or that damage adjacent properties by increasing flood heights or velocities. It also briefly considers the liability of landowners, contractors, builders, banks, real estate brokers, and insurance agents. Targeted to professions in those businesses. The initial sections of the paper explore professional liability. The final section makes recommendations for staying out of legal trouble.

Design Professional’s Duty to Design to Mitigate against Damages from Extreme Weather Events

A legal white paper by Zurich Insurance targeted at the construction industry. Talks about enhanced standards of care in an age of changing climate and how meeting code may not be a sufficient legal defense with flood mitigation. Also talks about how the foreseeability of harm may create independent duty of care.

City of Conroe Ordinance Re: Construction in Floodways Provisions for flood hazard reduction.

City of Houston 2022 Infrastructure Design Manual  See Chapter 9 for Stormwater Quality, Stormwater Requirements and Low-Impact Development.

Harris County Guidelines for Atlas 14 Implementation for Current or Proposed Projects Affecting Rights of Way

Harris County Interim Guidelines and Criteria for Atlas 14 Implementation

Harris County Flood Control District Policy, Criteria, and Procedure Manual

Harris County Floodplain Regulations

Harris County Floodplain Regulations (with revisions shown)

Harris County Infrastructure Regulations as of 9/19/2020

Harris County Infrastructure Regulations (with revisions shown)

Harris County Recommendations on Minimum Standards for Communities in Harris County and Draining into Harris County

Harris County Engineer’s Report on How Building Regs Affected Damage during Hurricane Harvey. While 154,170 homes (roughly one in ten) in Harris County flooded during Harvey, only 0.6% of those built to regulations in effect after 2009 flooded. See what made the difference.

Liberty County Road and Drainage Standards for Subdivisions, including ditches (7/27/04)

Liberty County Subdivision Rules – 2004 version.

Liberty County Subdivision Rules – 2019, includes drainage regulations.

Liberty County Flood Damage Prevention Ordinance – 2004 Version

Liberty County Flood Damage Prevention Ordinance – Updated October 2020

Drainage standards for developments in Liberty County, Texas.

Liberty County Hazard Mitigation Action Plan

From hazard and risk assessment to mitigation strategies and planning procedures. Published 10/22/18.

Liberty County Strategic Plan

A blueprint for growth in Liberty County.

Liberty County Water Control Improvement District Drainage Criteria Manual, August 2016

Contains guidelines for stormwater detention in new developments and specifies “no adverse impact” for upstream or downstream properties.

Montgomery County Subdivision Rules and Regulations

Adopted in 1984, these rules, regulations and requirements relate to the approval and acceptance of improvements in subdivisions. See Page 12 (Development within the floodplain); Section III (Storm Sewers including runoff calculations, etc.); Section IV (Sediment control and sedimentation ponds); and Section V (permanent erosion control). Of special interest to Elm Grove residents suing Perry Homes, see section IV starting on page 28.

Montgomery County Atlas-14 Requirements effective 1.1.19.

Montgomery County Floodplain Regulations

Regulations affecting new developments designed to reduce flood hazards in Montgomery County, Texas. Permit requirements for developers.

Montgomery County Drainage Criteria Manual

Guidelines in effect in Montgomery County, Texas, for designing drainage structures such as ponds, storm drains, culverts, etc.

Montgomery County Hydrology and Hydraulic Analysis Guidelines

Designed to ensure no adverse impacts to the base flood elevation for development in floodplains.

Primary documents on which original bids for West Fork Emergency Dredging project were based

Caution: large downloads in come cases because of large number of visuals.

U.S. Army Corps of Engineers Plans for Dredging

For West Fork of the San Jacinto. Shows where, how wide, and how deep. This is the document that bidders based bids on.

U.S. Army Corps of Engineers Specs for Dredging

Companion document to the one above. This gives instructions for everything besides where, how wide and deep.

U.S. Army Corps of Engineers Value Engineering Study from May 7, 2018

Further elaborated on the plans and specs. Helps explain some of the concepts the Corps considered in structuring the job.


Amendment #1 increased the amount to be dredged by more than 2X.

Amendment #2 made a minor adjustment to expand scope of dredging and extend the bid deadline.

Amendment #3 made several changes to contract requirements, quantities and payments.

Amendment #4 extended bid deadline again, this time by six more days.

Amendment #5  changed quantities and several contract requirements again. This amendment contains a complete set of 27 updated project drawings.

Amendment #6 extended the bid deadline a third time, this time to June 22, four additional days.

Amendment #7 changed quantities again and added dredging through the side bar at River Grove Park.

Amendment #8 changed the plan for dredging through the side bar at River Grove Park.


First Bids for Emergency West Fork Dredging Project

Revised Bids after vetting

Mouth Bar Issue

The Case for Expanding the West Fork Dredging Project Scope 

An analysis of West Fork San Jacinto River and Lake Houston Flow Profiles, Bathymetry, Associated Landforms and Impact on Flooding by R.D. Kissling, Tim Garfield and Bob Rehak, July 23, 2018. A 28-page presentation in PDF format. It explains how the river is changing, why it’s crucial to remove the mouth bar (which was excluded from the Corps Emergency West Fork Project), and what will likely happen if we don’t. Illustrated with charts and graphs.

A Brief History of Lake Houston and the Hurricane Harvey Flood

The Combined effects of Record Rain, Human Error and Predictable Geomorphic Processes by Tim Garfield,  Randy Kissling and Bob Rehak. Presented by Tim Garfield to the University of Houston Honors History Program. A look at how geologic and human history intersected on one ill-fated night in August of 2017, and continued efforts to rectify the errors.

Evaluating West Lake Houston bathymetry, dredging status and recommendations

By Tim Garfield and RD Kissling, September 2020. Evaluates the lake and river bottom in an attempt to identify the best strategy for dredging an additional million cubic yards from the area of the West Fork San Jacinto mouth bar.

Future Dredging

Plans as of 7/9/21 to Extend Dredging to East Fork and Lake Houston

Presented by Stephen Costello at Kingwood Community Center

Galveston Bay Regional Programmatic Sediment Management Plan,

From March 2010. Posted here at the suggestion of Harris County Flood Control as an example of what really needs to be developed for the San Jacinto Watershed. Think of this as a comprehensive template, not specific recommendations for the San Jac. Why is a long term sediment management plan so important? So governments can budget for it, and not scramble around looking for emergency funding.

Active Construction and Maintenance Projects  A GIS database showing the location of all active Harris County Construction and Maintenance Projects. Updated monthly during the first week.

Huffman Area Drainage Assessment

Presentation by District at Huffman community meeting on 7/11/2019 to update community on status of flood mitigation projects in three watersheds (East Fork, Luce Bayou and Cedar Bayou).

Kingwood Drainage Assessment

Background, scope and bidding doc.

Kingwood Drainage Assessment

Summary of 600-page final report.

Contract with Neel-Schaffer for Engineering Services

Final HCFCD Harvey Report,

Harris County Flood Control District’s Final Report on Hurricane Harvey is fascinating compendium of statistics. 32 pages in total. It’s your ultimate and authoritative guide to Harvey trivia in case Jeopardy ever decides to base a game on the event. How many cars did Harvey destroy? What was the peak rainfall amount? How did Harvey’s damage compare to other storms? What was the impact in your part of town? How many times did the alarm sound for one inch of rainfall in 15 minutes? (Answer: 336 times!) Relive the excitement!

Harvey Impact and Response,  May-2018

A pictorial version of HCFCD’s final Harvey report. Much higher level. Doesn’t contain as much information. But captures the human impact in a way that the data does not. (9 meg pdf)

Timeline: What the Harris County Flood Control District Did in the Year Following Harvey

What happened in terms of flood mitigation between August 2017 and August 2018 from a Flood Control District perspective.

July 2022 Spending and Project Update from HCFCD on Flood Mitigation Projects in Bond.

June 2022 Spending and Project Update from HCFCD on Flood-Mitigation Projects in Bond.

May 2022 Spending and Project Update from HCFCD on Flood-Mitigation Projects in Bond.

March 2022 Spending and Project Update from HCFCD on Flood-Mitigation Projects in Bond.

February 2022 Spending and Project Update from HCFCD on Flood-Mitigation Projects in Bond.

December 2021 Spending and Project Update from HCFCD on Flood-Mitigation Projects in Bond.

August 2021 Spending and Project Update from HCFCD on Flood Mitigation projects in Bond.

Project List for Flood Bond Updated as of March 2021 (includes spending updates, consolidated projects, completed projects and more).

Project List for Flood Bond Updated as of May 2020 (includes spending updates, consolidated projects, completed projects and more)

Project List for Flood Bond as of August 6, 2018

Project List for Flood Bond as of August 1, 2018

Project List for Flood Bond as of July 19, 2018

Project List for Flood Bond as of June 29, 2018

Watershed-by-watershed list of recommended projects for Harris County’s $2.5 Billion Flood Bond Referendum. Historical versions of this list are preserved so you can see how it evolved as a result of meetings with residents in 23 watersheds. Early voting starts August 8. Final day to vote will be August 25, the anniversary of Harvey.

Final Bond Language

This is what voters approved. The project list can be changed in the future to give the Flood Control District flexibility to achieve these objectives.

Equity Guidelines Adopted by Harris County Commissioners Court

Redefined the common definition of equity found in most dictionaries to favor certain income segments. Includes a multi-factor index that reprioritized the execution order of flood bond projects.

Funding Flood Resilience in Harris County

Presentation made by Alan Black of HCFCD about how HCFCD proposed funding construction of flood mitigation projects without delays in the event partner funding doesn’t materialize as planned. Black proposed transferring $40 million per year from HCTRA funds and Commissioners unanimously approved on 6/28/2021.

Final Bylaws of Community Flood Resilience Task Force

There are the bylaws of a community task force set up to ensure that bond dollars are being spent according to the “equity” guidelines approved by Harris County Democratic Commissioners almost two years after the bond was approved.

Minimum Drainage Recommendations

What communities within Harris County and also those draining into Harris County must do if they wish to partner with Harris County on Flood Bond projects.

2018 Federal Briefing

An overview of the Harris County Flood Control District, how it operates, who it partners with, and all of the federal projects currently underway. Includes a section on Flood Control’s response to Hurricane Harvey. Filled with maps by watershed and congressional district. Warning: 33 meg download. After reviewing this, it suddenly became clear why people in the Lake Houston Area need to become more vocal; there are no federal projects here. That may explain why sediment has been building so long.

2019 Federal Briefing

Update on Harris County Flood Control District’s federal partnership projects for 2019.

City of Houston’s Harvey Data Project

Report on Harvey Damage for HUD from the City’s Housing and Community Development Department. Breaks down damage by neighborhood and how Harvey affected the most vulnerable.

FEMA Damage Map of Houston.

This interactive map shows where damage occurred throughout Houston including Kingwood and surrounding areas. It enables you to see how extensively Harvey damaged your neighborhood compared to others. Note the date: 9/2/17. This was a preliminary assessment and does not show all damage.

Harris County Needs Assessment from Hurricane Harvey

Report to the Texas General Land Office by the Harris County Community Services Department documenting unmet needs in the county after Harvey. Focuses primarily on low-to-moderate-income areas (LMI).

Harris County Engineer’s Report on How Building Regs Affected Damage during Hurricane Harvey. While 154,170 homes (roughly one in ten) in Harris County flooded during Harvey, only 0.6% of those built to regulations in effect after 2009 flooded. See what made the difference.

Harvey Inundation and Rainfall Map

Across the entire San Jacinto River Basin with peak flows, gage readings and overbank flood heights near every gage.

The Harvey Story in Montgomery County

An interactive GIS (geographic information system) site by ESRI focusing on flood damage in Montgomery County Texas. Also includes flood damages from Memorial Day, Tax Day and 1994 floods. Zoom into any part of the county and see exactly how many homes flooded there.

Houston Flooding and Flood Plains: Past Present and Future

By Dr. William Dupré, Professor Emeritus of Atmospheric and Earth Sciences from the University of Houston. A presentation in two parts that explains the science behind flood forecasting and floodplain delineation. Part One provides a basic understanding of flooding, hydrology and measurement. Part Two explains how and why floodplains change.

Houston a Year After Harvey: Where We Are and Where We Need to Be 

By Jim Blackburn, JD, professor of environmental law at Rice and Phil Bedient, PhD., professor of engineering. Excellent summary of what happened, how the community is responding, and what still needs to be done – watershed by watershed. August 2018. 55 pages. Posted here with permission of Rice University’s Baker Institute for Public Policy and SSPEED Center. ©2018 James A. Baker III Institute for Public Policy of Rice University.

Novel 4-pane mapping tool allows users to view pre- and post- Hurricane Harvey natural color as well as Color InfraRed imagery. It is very helpful when looking at how river and stream channels changed before and after the storm. Zooming and scrolling in the upper-left pane automatically zooms and scrolls the other panes to match.

Hurricane Harvey Impact and Response Book 

Powerful photos, stories and diagrams that tell the story of the storm and mitigation plans. Produced for HCFCD by Holloway Environmental in May 2018. 48-page downloadable PDF.


This 82-page presentation by the San Jacinto River Authority discusses the difficulty of forecasting storms, such as Harvey, and lays out the rationale for the steps the San Jacinto River Authority took in releasing water from the Lake Conroe Dam.

NOAA Atlas 14 Rainfall Intensity Map for Texas

The map above shows 24-hour/100-year contour intervals for the entire state of Texas. To find precise figures for the gage nearest you, go to the Precipitation Frequency Data Server – PFDS. This will show you a table of figures for different time periods and recurrence intervals. To compare the new data to two comparable previous studies, see the 1961 NOAA study or the 2004 USGS study.

Peak Flow Data of San Jacinto and Tributaries During Harvey

This map shows the contribution of various streams to all the water that hit us during Harvey, including from Lake Conroe. It’s based on USGS stream gages and was compiled by the San Jacinto River Authority. All figures expressed as CFS (Cubic Feet per Second).

San Jacinto Flooding, 8/2017

A 92-page report filled with facts, figures, statistics maps and interpretations. Covers every aspect of the basin from both historical and Harvey perspectives. By Kingwood’s David Seitzinger, PE. Focuses on six obstructions and the backwater effects they created. Also looks at timing issues.

San Jacinto Watershed: Where All the Water Comes From

This helpful map compiled by Charlie Fahrmeier shows wher e the water comes from that flows past Kingwood and the Upper Lake Houston Area. Charlie outlined all the tributaries of the West Fork of the San Jacinto in red, and all the tributaries of the East Fork in Green.

San Jacinto River Tributaries and Their Watersheds with Square Miles Drained

A map produced for the San Jacinto River Basin Master Drainage Plan. Shows the square miles of each

State of Texas Disaster Recovery Plan Draft

For Hurricane Harvey, Round 1. This is the first fully amended report published on September 6, 2018. The public comment period ended on October 6, 2018. Prepared by the Texas General land Office, Community Development & Revitalization Program. It was approved by the U.S. Department of Housing and Urban Development (HUD) on June 25, 2018. This incorporates Harris County and City of Houston Local Action Plans.

State of Texas Comptroller’s Report

On the Economic Impact of Harvey. Shows the initial negative impacts from lost productivity and then a rebound effect as people spend money to repair and replace losses. Sadly, this does not factor in the depletion of savings and how that will impact people in their retirement years.

Texas Water Development Board Statewide Assessment of Flooding

69-page report on flooding issues common to many parts the state. Does not get into watershed-by-watershed detail but does a good job of outlining how we can improve flood mitigation. Note this is a first draft dated 9/18.

USGS Report on Peak Streamflows and Flood Inundation Maps

…of Selected Areas in S.E. Texas and Louisiana resulting from Hurricane Harvey. See pages 35 and 36 for maps of the Harris and Montgomery County area. Caution: 10 meg pdf file; may be slow to open.

Slate Magazine Article about Floodplain Development in Houston

Well-researched article about how City of Houston approved a 900-home development in an area already prone to flooding where many homes were being bought out. Underscores the need to give rivers more room.

Scope of Work for Preliminary Engineering. Outline of work involved in Phase 1 of project designed to reduce flooding by adding more gates to Lake Houston Spillway.

Plans being Considered by Army Corps for Permitting Five page PDF showing location and layout.

Army Corps Public Notice  Contains a high level overview. Public comment period closed 8/23/2021.

Gates Alternatives Analysis  Describes alternatives being considered in design process. Lists pros and cons of each along with a thorough description.

July 2022 Project Update

July 21 Project Update. Presentation by Chris Mueller of engineering firm Black & Veatch  about engineering objectives, constraints, and recommendations.

Laws and Regulations for Professional Engineers in Texas

If you think an engineer has fudged a report to please a client and that it jeopardizes public safety, you should read Chapter 137, Subchapter C. It explains professional conduct and ethics for engineers in Texas. Chapter 139, Subchapter B explains how to file a complaint.

Legal Issues and No Adverse Impact Workshop

A 2009 presentation for the Texas Water Development Board, Texas Floodplain Management Association and others about legal issues having to do with developing in floodplains. 201 pages! Discusses private property rights versus public safety, and whether upholding the principle of “no adverse impact” constitutes a “taking” by regulators. Includes hundreds of years of legal precedents. A must-read paper for those who think people have unlimited rights to do what they want with the property, even if it harms others. By the head of the National Hazard Mitigation Association.

Model Local Laws to Increase Resilience

A catalog of local laws compiled by New York State that address a variety of flooding issues. It not only provides valuable background information, it provides templates for the legal language.

Professional Liability for Construction in Flood Hazard Areas

A legal paper from the Association of State Flood Plain Managers. It addresses the liability of architects, engineers, landscape architects, surveyors, floodplain managers and other professionals in designing or constructing structures that are subsequently damaged by flooding or that damage adjacent properties by increasing flood heights or velocities. It also briefly considers the liability of landowners, contractors, builders, banks, real estate brokers, and insurance agents. Targeted to professions in those businesses. The initial sections of the paper explore professional liability. The final section makes recommendations for staying out of legal trouble.

Design Professional’s Duty to Design to Mitigate against Damages from Extreme Weather Events

A legal white paper by Zurich Insurance targeted at the construction industry. Talks about enhanced standards of care in an age of changing climate and how meeting code may not be a sufficient legal defense with flood mitigation. Also talks about how the foreseeability of harm may create independent duty of care.

Stormwater Pollution Prevention Plan Requirements 

A template provided by the EPA that explains SWPPP plans, what they must include, and options for attaining various goals. This is the template for large construction sites.

TCEQ SJR Watershed Report 2015

A deep dive into highly technical data about bacteria in the San Jacinto River Watershed. From 20o15. “Second Update, Technical Support Document for Total Maximum Daily Loads for Indicator Bacteria in Lake Houston, East Fork San Jacinto River, West Fork San Jacinto River, and Crystal Creek Watersheds.” 79 pages of charts, graphs, tables and maps.  

Sustainability of Sand Production

A worldwide look at the sustainability of sand production by the United Nations Environment Program.

SJRA Master Plan Report From 1957 

Contains the history of the SJRA and the objectives originally given to the Agency by state legislators. See Pages 7 and 8.

San Jacinto Upper Watershed Drainage Improvement and Flood Control Planning Study from 1985

By Wayne Smith & Associates for the Texas Water Development Board and SJRA. Well written and exceptionally easy to understand for an engineering study. At the time this was done, Montgomery County was only 5% developed. The recommendations were prophetic. Had someone only acted on them!

SJRA History and the Struggle to Fund Lake Conroe

See Chapter 4 of this history doctoral dissertation by Andrew C. Baker, PhD, from Rice University


An SJRA doc that explains their reasons and timing for opening the floodgates of the Lake Conroe dam during Harvey. Spoiler alert: you may not agree with all their answers, but it’s a good starting point for discussion.

Resolution Establishing Flood Mitigation Division of SJRA

Full text of resolution-07 from 4/26/2018.

SJRA Enabling Legislation

Includes updates and sunset review in 2021.

SJRA Self-Evaluation Report for Sunset Review Commission

How the SJRA perceives its own performance relative to its objectives. Contains information on strengths, weaknesses, opportunities and threats. Read before submitting public comments to the Commission.

San Jacinto Regional Watershed Master Drainage Plan

PowerPoint used in a Virtual Public Meeting on August 13, 2020 to report the preliminary findings of the plan. Final report is due by end of 2020.

San Jacinto Regional Watershed Master Drainage Plan Updates

Information includes non-regulatory inundation maps (not intended to replace current effective maps) for the studied streams that show the extent and depth of riverine flooding of the larger rivers within the watershed for an array of simulated storm events. Plan results will be used to inform and update Hazard Mitigation Plans for each of the participating partners and to provide guidance on regulations for future growth within the study area.

SJRA Gate Operations Policies and Statistics During Harvey

Affidavit of Freese and Nichols Partner and VP Hector Olmos. Olmos helped define the Gate Operations Policy in use during Harvey. Statistics at the end of the affidavit show how the policy was put into action during the storm. For a discussion of the statistics and questions they raise, see this post.

SJRA Report to February 2020 Board Meeting by Chuck Gilman

Correlates rainfall to rise in Lake Conroe levels. Contains staff recommendations on lake-lowering policy.

Kaaren Cambio’s April 2018 Flood Mitigation Project Update   View SJRA Board Member Kaaren Cambio’s presentation to the April Meeting of the Lake Houston Area Grass Roots Flood Prevention Initiative. It contains updates on the status of numerous flood mitigation projects underway in the San Jacinto watershed.

SJRA Grant Applications

TWDB abridged application for development of a joint reservoir operations plan for Lake Conroe and Lake Houston.

TWDB abridged application for development of a flood early warning system for San Jacinto county.

TWDB abridged application for preliminary design of sand traps.

TWDB abridged application for Spring Creek Watershed Flood Control Dams Conceptual Engineering Feasibility Study

TWDB abridged application for Upper San Jacinto River Basin Regional Sedimentation Study


10 Sand Mining Practices that Could Help Reduce the Rate of Sedimentation into the San Jacinto River and its Tributaries: A Starting Point for Discussion

By Bob Rehak,  August 1, 2018, Compares actual sand mine practices on the West and East Forks of the San Jacinto to the best management practices around the world. Includes ten recommendations that could reduce the rate of sedimentation if universally followed.

House Interim Report on APOs, January 2021

Discusses a variety of issues related to sand mining in Texas with a special focus on the San Jacinto River basin. Includes dozens of recommendations for how to reform the industry.

West Fork Dredging, The Mouth Bar and Sand Mining

By Bob Rehak, 9/17/2018. Presentation to the Lake Houston Area Grass Roots Flood Prevention Initiative. (7 meg pdf).

The Case for Expanding the West Fork Dredging Project Scope 

An analysis of West Fork San Jacinto River and Lake Houston Flow Profiles, Bathymetry, Associated Landforms and Impact on Flooding by R.D. Kissling, Tim Garfield and Bob Rehak, July 23, 2018. A 28-page presentation in PDF format. It explains how the river is changing, why it’s crucial to remove the mouth bar, and what will likely happen if we don’t. Illustrated with charts and graphs.

West Fork Sand Stockpiles: Before, During and After Hurricane Harvey

A collection of satellite images from Google Earth showing stockpiles of sand at West Fork sand mines before, during and after Hurricane Harvey. The sequential images show how Harvey (and the release of water from the Lake Conroe dam) reduced stockpiles and moved sand downstream.

Sand Deposits and Flooding along the San Jacinto River By Bob Rehak 2018

An aerial survey, 58 pages long, containing photographs of fresh sand deposits in and along the shores of the San Jacinto River shortly after Hurricane Harvey in 2017. It shows several major blockages of the river and its tributaries with sand reaching into treetops in places.

Sand Deposits and Flooding Condensed by Bob Rehak 2018

Same as above but shorter and focusing on the most severe blockages.

DIG IT by Keith Jordan 2017 

A Kingwood geologist uses his knowledge to put Harvey flooding into a historical context. Contains recommendations to prevent flooding and a suggested timetable for implementation.

SJR Flooding: Cause, Impacts, Potential Solutions by David Seitzinger, PE 2018

A Kingwood resident’s look at chokepoints along the San Jacinto and the breadth of watershed issues from an engineer’s perspective.

2006 Article on San Jacinto Being One of Ten Most Endangered Rivers

…Because of sand mining. While somewhat dated, it’s interesting from a historical perspective. Also note, the problem has only gotten worse since then.

Sand Mining Best Practices, Regulations and Research

Link to a whole page of this website dedicated to cataloging best practices, regulations and research regarding sand mining.

Government Surveys and Plans

Brown & Root Regional Flood Protection Study 2000

A 734-page engineering study conducted by Brown & Root after previous record floods in 1994 and 1998. The study examined several different approaches to flood control, including dredging. It found that river sand was suitable for use in construction.

Volumetric Survey of Lake Houston 2003

Shows almost 12,000 acre/foot loss since previous survey (almost 9% of lake volume). Also shows that majority of sedimentation was upstream from FM1960 bridge, not downstream.

Volumetric and Sedimentation Survey of Lake Houston: 2011

Discusses impact of new methodology on new volume predictions. 45 pages. Shows Lake Houston has lost 25% of its capacity due to sedimentation since construction.

Volumetric and Sedimentation Survey of Lake Houston: 2018

The 2018 TWDB volumetric survey indicates Lake Houston has a total reservoir capacity of 136,119 acre-feet. Original design estimate was 158,553 acre-feet.

West Fork Difference Map

Shows where sediment has built up since 2011 and how the City hopes to phase dredging.

West Fork Difference Map. Red/orange/yellow/green areas represent decreases in sediment since last survey. Blue, violet and white represent increases.

NRCS Report on Soils in Montgomery County

This map shows where the greatest concentrations of sand are in Montgomery County. The NRCS (National Resources Conservation Service) is part of the U.S. Department of Agriculture. Blue areas have the highest concentration of sand in the soil and red the lowest.

Subsidence can affect flooding by lowering ground levels unequally. The following reports from the Harris-Galveston Subsidence District and the Lone Star Groundwater Conservation District all contain information about subsidence affecting the Humble/Kingwood/Lake Houston Area.

Harris County Flood Control District

Discussion of the Effects of Subsidence on Flooding from 1995

By Michael Talbott, P.E., Engineering Division Manager of the Flood Control District at the time. Describes different types of subsidence, and how they relate to flooding and flood insurance surveys.

Harris-Galveston Subsidence District

The Past, Present and Future of Subsidence in the Houston Region

Presentation by Michael J. Turco, General Manage of the Harris-Galveston Subsidence District dated 8/28/18. A great intro to subsidence in this region. Begins by describing the history, the aquifers, mechanisms for subsidence in the Gulf Coast, and examples. Topographic maps show subsidence in various areas. For instance, most of Kingwood lost two feet between 1906 and 2000, and even more since then. Kingwood continues to decline by about a half inch per year. However, parts of western Harris County are subsiding by approximately .75 feet per year.


Investigates brackish groundwater resources in the Gulf Coast Region and potential subsidence risk due to resource development. This is the overview of the next report below which contains all of the scientific detail. The results of this study confirm the potential for compaction in the Jasper aquifer and subsidence to occur particularly in up-dip areas near where the Jasper is being used for freshwater supply.


This contains all the scientific data for the summary report above. It contains all the detail that scientists, engineers, regulators and geotechnical people will need to evaluate the conclusions above. If you want to know the compressibility of clay based on its mineralogy, this is for you.

HGSD Subsidence Contour Map from 1906-2000

Shows elevation changes in 1-foot isobars between 1906 and 2000.

Lonestar Groundwater Conservation District (Montgomery County)

Ground Water Production and Water-Level Monitoring – Phase One of Stategic Plan

Graphs groundwater pumping in Montgomery and surrounding counties over time and shows impact on levels of different aquifers. Found dramatic decreases in the Evangeline and Jasper Aquifers. Also found Montgomery County had a dramatic increase in pumping while surrounding counties generally decreased since 2000.

Ground Water Observations/Estimated Recoverable Storage– Phase Two of Strategic Plan.

Prepared by LBG-Guyton Associates, May 24, 2016. Review of the total estimated recoverable storage (TERS) by the Texas Water Development Board and implications for groundwater management. Also assesses potential volumes of fresh and brackish groundwater in the TERS volume within the District. Finally estimates subsidence for various points in Montgomery and North Harris Counties.

Strategic Planning Summary and Results – Phase Three of Strategic Plan

Evaluated the impact of four different pumping scenarios on drawdowns in wells drilled into various aquifers in Montgomery County. The most likely scenario based on projected growth in water demand shows a 224 foot reduction in the level of the critical Jasper aquifer.

A Study of the Relationship Between Subsidence and Flooding: Executive Summary

A 1986 joint-study by three engineering firms (Turner Collie & Braden Inc., Page Engineers Inc. and Winslow & Associates Inc.) for Harris County Flood Control District, City of Houston, Harris-Galveston Subsidence District and Fort Bend County Drainage District. Dated at this point, but establishes the relationship between subsidence and flooding, describes its nature, and outlines the limits. Although the principles are still valid today, the specifics have changed in the last thirty years with actual subsidence. Includes an analysis of riverine flooding useful for people studying the San Jacinto watershed. Altogether, it builds a good case for conversion from groundwater to surface water.


“Houston, we have a groundwater problem.”

September, 2018, presentation by the SJRA explaining how excessive groundwater withdrawals can affect the l201vel of aquifers, reliability of wells, and long-term water production. A good resource for those looking for hard data about the groundwater debate. (6 meg pdf)

Why Responsible Groundwater Management Matters

White paper that addresses claims made by City of Conroe consultants in the groundwater debate. Uses a point/counter point style almost like a debate in print. Easy to understand and follow for anyone who wants to understand both sides of the issue.


USGS Article about Recharge Rates

For aquifers in Montgomery County, Texas. Shows the rate in the crucial Jasper aquifer averages about one-tenth of an inch per year.

USGS Subsidence Data from 2009

A 1-page oversized placemat presentation of subsidence issues in the region at the time. Useful for historical context and comparison. Contains a good overview and a large graphic of aquifers in the Gulf Coast region of Texas. Large download (8.5 megs). Page 1 of 2 (see next item).

USGS Subsidence Map with LIDAR from 2009

Another 1-page oversized placemat presentation. Page 2 of the doc above. But this page contains a LIDAR “heat” map showing estimated land-surface subsidence from 1915–17 to 2001, in feet. Let’s you see at a glance where the most and least subsidence was in Harris County during the last century. Somewhat dated in 2018, but nonetheless useful for historical context and comparison. Another large download (15.9 megs).

Bill Fowler’s Report on Tax Appraisals and Protests in the Wake of Hurricane Harvey.

Delivered at the June, 2018, meeting of the Lake Houston Area Grass Roots Flood Prevention Initiative. PowerPoint format.

Humble ISD 2017 Reappraisals For Flooded Properties

What to do to get a refund if you flooded.

East Fork Sand Mine Appraised as Timberland

Post about how the Guniganti mine on Caney Creek reduced its tax burden.

Inconsistencies in Sand Mine Appraisals

A clean sweep. After examining 53 parcels of land used for sand mining in Montgomery County, not one was appraised properly.

Montgomery County says it will re-evaluate sand mine appraisals

Report summarizing this series of post and what the Montgomery County Appaiser’s Office is investigating.

Flood Infrastructure Fund (SB7) Intended Use Plan

TWDB Community Assistance  Here’s my post on another Texas Water Development Board website with dozens of links to just about every flood-related topic you can imagine. From building codes to flood insurance and advice for community officials, this page has it all. Includes a Community Official Flood Resource Guide.

GLO Imelda Action Plan for Distributing HUD Grants

Proposed rules for the distribution of almost $213 million in HUD funds. 70% will go to low-to-moderate income persons and 80% must go to most-impacted-and-distressed areas as a matter of national policy. Read all the details on who’s eligible for what for the two big floods that struck Texas in 2019. 133 pages. 6 meg download. For an overview, see this post. 

Immediate Flood Report #1

The first post flood report detailing the rainfall and flooding associated with Tropical Storm Imelda. This report also compares Imelda against other major storm events in the last 5 years and also Tropical Storm Allison with respect to rainfall and rainfall rates.

Final Imelda Report from Harris County Flood Control

37-pages packed full of statistics, maps, tables and charts. A real work of scholarship. It helps explain some of the unusual flooding patterns seen during Imelda. 62% of homes that flooded were outside the 100-year floodplain, for instance. Why? Incredible short-duration downbursts that overwhelmed the capacity of storm drains.

Final Imelda Report from National Hurricane Center

28-pages, also packed full of statistics. Did you know that Fannett, Texas receives 31 inches of rain in 12 hours! Covers a wider area than Harris County. Includes impacts on surrounding states.

SJRA Peak Streamflow Report During Imelda

This map shows how much rain fell on different gages throughout the watershed and what the peak streamflows were for each. Within the space of 25 miles, rainfall rates ranged from 0″ in Tomball to almost 30″ in New Caney. From one side of the watershed to the other, there was a 1500X difference in peak streamflow rates. A good science less for kids. Dramatizes why you need to look upstream on your tributary to get a feel for flooding.

How Wetlands Influence Development – A 114-page PowerPoint in PDF format that describes how the US Army Corps of Engineers goes about determining whether land is “wetlands” and then delineating their extent. Also includes a discussion of “jurisdictional determination.” Useful for anyone trying to develop or conserve land. File Size = 5.9 megabytes.

Jurisdictional Determinations and Delineating Waters of the U.S., including Wetlands

A 114-page presentation by the Army Corps designed to help people understand whether wetlands fall under the Corps’ jurisdiction. Covers regulations, guidelines, precedents, types of wetlands, standards, and how/where to seek definitive guidance.

Stemming the Flow: The Role of Trees and Woodland in Flood Protection

An informative policy paper by the Woodland Trust in the UK.

US Army Corps of Engineers Galveston District Regulatory Program – A 67-Page PowerPoint in PDF format.  Similar to the PowerPoint above but with a little more of a “how to” emphasis. Targeted to people applying for permits or wondering whether they need to apply for permits to fill land that MIGHT be considered wetlands. File size = 6.3 megabytes.

Wetland Delineation Manual 

By US Army Corps, updated in 2010, for the Gulf Coast Region.

Wetland Protection Legislation

Published by USGS. By Todd H. Votteler, University of Texas and Thomas A. Muir, National Biological Service. An extensive compilation of all the federal laws and regulations affecting wetlands, one way or the other. Some discourage wetland conversion and others encourage it.

2018 FloodWarn Workshop Presentations from 5/1/18 at Kingwood College.  Presentations by: 1) the National Weather Service about how they develop river forecasts and communicate risk; 2) Harris County Flood Control about hydrology in Harris County, warning systems, future enhancements, inundation mapping, and gage system expansion; 3) San Jacinto River Authority about Lake Conroe Dam operation and the release of water during Harvey; 4) and FEMA about  flood risk, hazard mapping and flood insurance.

Army Corps Presentation on Flooding Along Buffalo Bayou and its Tributaries

Resiliency Study update from Spring, 2019, helps readers understand how much further ahead mitigation is on the west side of Houston.

Army Corps of Engineers: Water Resource Authorization and Project Delivery Processes

April 2019 paper explaining how the Corps has tailored processes around the Water Resources Development Act (WRDA) and why WRDA funding is so important. Also explains why/how projects are funded in phases.

Army Corps of Engineers: Buffalo Bayou and Tributaries Resiliency Study, Texas, October 2020

A review of flood mitigation alternatives for Buffalo Bayou and its tributaries. One alternative would create a third dam on the west side of Houston along the upper Cypress Creek watershed to keep floodwater from spilling over into the Addicks reservoir as it did during Harvey. If this alternative is selected for construction, it could help reduce flooding in the Lake Houston Area.

CHARM (Community Health and Resource Management)

A program of Texas A&M Agrilife Extension. This presentation shows the results of a workshop in east Montgomery County. Attendees were county and city officials. The challenge was to double the growth of cities like Conroe and Patton Village without creating more flooding. Interesting real-world exploration of GIS mapping tools, mitigation strategies and planning concepts.

Conservation Flood Planning in Texas

A study by Dr. Matthew Berg first published in Texas Water Review. It examines dozens of ways that engineering and conservation are coming together to form more effective flood-mitigation solutions.

Dave Martin’s April 2018 Flood Mitigation Project Update View Houston City Council Member Dave Martin’s Presentation to the April Meeting of the Lake Houston Area Grass Roots Flood Prevention  Initiative. It contains updates on the status of numerous flood mitigation projects.

EPA Stormwater Management

The User Manual for Version 5.1 of the EPA’s Storm Water Management Model. Used by engineers and hydrologists to plan construction and compute runoff. Cited by LJA Engineering in its plans for Woodridge Village, the development that allegedly flooded hundreds of Kingwood residents in May of 2019.

Flood Mitigation Problem Solving Flowsheet A light hearted look at the serious business of flood mitigation. Posted here in downloadable PDF format because sometimes you need to smile.

Freese and Nichols Report on the Effect of Adding Floodgates to Lake Houston. Study finds that additional gates could have reduces flooding during Harvey by up to 1.9 feet.

“Green Development” Article in Builder Online Magazine

How to manage excessive water on construction sites. Surveys things builders are trying to do to minimize their impact on flooding. Mentions two local developments: One in Harris County and the other in Montgomery. The Harris County site is controversial because of trying to build hundreds of homes on a golf course in the 100 year flood plain.

Greater Houston Flood Mitigation Survey, April 5, 2018

This 64-page report was developed by a large coalition of interests representing the entire region. It begins with a discussion of the pros and cons of various strategies in general. Then it looks at strategies that apply to each watershed within the region. Their discussion of recommendations for the San Jacinto Watershed begins on page 48 and continues on page 49. The report also points out that the San Jacinto watershed contains 3% of the region’s population, gets 0% of the budget, and had 14% of the region’s damages. Note: this file is a large download, direct from Google.

Greater Houston Flood Mitigation Consortium Report on Affordable Multi-Family Housing, March, 2019

108-page richly documented report on the dwindling supply of affordable multi-family housing in the Houston area and what can be done about it. Warning: 50-meg PDF.

Greater Houston Flood Mitigation Consortium Report on Detention Pond and Drainage Requirements.

This report discusses Houston’s requirements and whether they are enough. A primer on all the factors that go into determining detention pond capacity.

Growing Threat of Urban Flooding: A National Challenge – 2018

By research teams from The University of Maryland and Texas A&M Galveston. Packed full of statistical analysis and insights from across the U.S. Targeted to government officials and urban planners, but will help the average homeowner understand why flooding is so severe and why flood mitigation is so difficult.

Harvard Study on Ways to Improve Buyout Process 

“Floodway Buyout Strategy for a Resilient Houston: A Systems Approach to Breaking the Dangerous and Expensive Cycle of Rebuilding in the Floodway.” Tries to answer the question of why people would choose to rebuild in a floodway up to 40 times before accepting a buyout to move to a safer place. Also makes 13 recommendations to address this problem. Study done for City of Houston.

Houston at a Crossroads: Reliability and Sustainability in the 21st Century By Jim Blackburn and the James Baker Institute at Rice. Discusses long-term trends affecting the Houston area and how to turn our liabilities into assets for the future. Very high level.

Huffman Area Drainage Study Scope of Work

By the Harris County Flood Control District. Doc outlines scope of work which is described as an engineering investigation.

Lake Conroe Press Release from City of Houston and San Jacinto River Authority about TCEQ approval

…of the decision to lower Lake Conroe. See also the text of TCEQ approval letter.

Lake Houston Area Flood Mitigation Update

Report on Multiple Projects by Stephen Costello, Chief Resiliency Officer for City of Houston.

Luce Bayou Watershed Plan Summary Report

Prepared for HUD, Texas General Land Office, Harris County Community Services, and Harris County Flood Control District by LJA engineering. Recommendation for a bypass channel was killed in Commissioners Court by Precinct 2 Adrian Garcia on 8/24/2021, citing local opposition from affected property owners.

The Need to Reduce Impervious Cover to Reduce Flooding and Improve Water Quality

Informative report published by Rhode Island and funded by the National Park Service explains the relationships between impervious cover and watershed degradation.

Rain by the Cubit: The Great Southeast Texas Flood of 1994

41-Page PowerPoint in PDF format by Andy Yung, PE, and Duance Barrett, PE, about the 1994 Flood. A great summary of the largest flood to hit the Lake Houston Area before Harvey. Kingwood received 29″ of rainfall during this event. Contains dozens of pictures of area lakes, rivers, homes and businesses impacted by the flood. Ironically, had the recommendations been followed, much damage during Harvey might have been averted.

ReBuild Houston

2018 Report on funding

Resilient Houston

City’s vision for the future.

San Jacinto River Basin Study Overview

2-Page summary outlining objectives and scope.

San Jacinto River Basin Study: Master Drainage Plan Detailed

Joint project funded by FEMA, SJRA, Montgomery County, Harris County Flood Control and City of Houston. This doc outlines the scope of work in intricate detail (as opposed to overview above).

San Jacinto River Basin Master Drainage Plan Draft Report

Draft final report from 8/13/2020 virtual presentation.

San Jacinto River Basin Master Drainage Plan FINAL Report

3600 pages broken down into multiple sections including one on sedimentation. This post explains a flaw in the sedimentation section which mars an otherwise excellent report.

San Jacinto River Flooding above Lake Houston

Presentation by Charles Jones, local resident and business man, about the role of the FM1960 bridge in Harvey Flooding.

San Jacinto Flood Planning Group (Region 6) 

Review of draft report released in August 2022 with link to full report.

Storm Surge and the Future of the Houston Ship Channel

By Prof. Jim Blackburn of Rice University and Amy Jaffe of the Council on Foreign Relations. Discusses the risks, importance, and possible mitigation strategies for dealing with a storm like Ike that comes up the throat of Galveston Bay, but with higher winds that could produce higher surge.

Stormwater Pollution Prevention Plans 

Their purpose, objectives, what goes into them and who is responsible for what. A high-level guide by the EPA suitable for public consumption. Not too intimidating.

Texas Water Development Statewide Flood Plan

Discussion guide for development of rules for the state’s first flood plan.

Texas Disaster Recovery Plan (Draft)

Published September 6, 2018, by Texas General Land Office Community Development and Revitalization Program. Public comment period ended October 6. Has not yet been approved by HUD.


By Brian Gettinger, PE, of Freese & Nichols. Describes how flood tunnels can add conveyance capacity.

Tunneling – Phase 2 Report

By Scott Elmer, P.E., CFM, Asst. Director of Operations, Harris County Flood Control. This post includes links to the presentation and virtual community meeting. It also includes a description of where/why tunnels make sense, six recommended routes, and how this study fits in with Phase 1 and Phase 3.

TWCA Report on Flooding in Texas

Pros and Cons of various flood mitigation strategies from a professional’s point of view. Read this to understand why some things work better than others in certain situations.