Major Storms
In Chronological Order:
1527 – 2008 Texas Hurricane History
By David Roth of the National Weather Service. Tells the story of 122 major storms to hit Texas.
1994 – Rain By the Cubit: The Great Southeast Texas Flood of 1994
By Andy Yung, PE, CFM of Dodson and Duane Barrett, PE, CFM of HDR Engineering, Inc.
1994 – Final HCFCD Report on 1994 Storm
The flood of record in the northern part of Harris County until Harvey in 2017. Dropped up to 30″ of rain. Exceeded 500-year flood levels. Water was 12 feet higher than the Lake Houston flood record.
1998 – Final HCFCD Report on 1998 Storm
Slow moving cold front that moved west to east across northern Harris County in November 1998 dropping up to 11 inches of rain. Caused flooding in Cypress, Little Cypress, Willow, Spring, Luce and San Jacinto Watersheds.
Dumped 28 inches of rainfall just northeast of Downtown Houston in a 12-hour period. The costliest tropical storm in US history. Dumped enough rain to meet the needs of the whole US for an entire year.
2008 NHC Reports on Hurricane Ike
Cat 5 storm that blew up off the Texas Coast and came straight up Galveston Bay and Lake Houston. Eye came directly over Kingwood. Wind damage knocked out power for 3 weeks because of trees falling on so many power lines. Dropped up to 18 inches of rain.
2016 – Final HCFCD Tax Day Storm Report
Summarizes the historic and devastating flooding from rainfall that occurred across Harris County late on the evening of the 17th into the 18th of April 2016.
2016 – Final HCFCD Memorial Weekend Storm Report
Summarizes the major flooding from excessive rainfall on May 26-27 over north and northwest Harris County, southern
Montgomery County, and northern Waller County.
2017 – Final HCFCD Harvey Report
Fascinating compendium of flooding statistics from the largest rainfall in the history of North America. 32 pages in total.
2019 – Final HCFCD Tropical Storm Imelda Report
The fourth wettest storm in Texas history when measured by total rainfall, Imelda produced incredible short duration rainfall rates that exceeded Harvey in the 5-, 15-, and 30-minute time periods. And that is the key to understanding why more homes flooded in the 500-year floodplain than the 100-year floodplain. 2019.
2020 – Final HCFCD Tropical Storm Beta Report
Produced up to 14.7 inches of rainfall in a 48 hour period, but frequent breaks limited flooding. Mainly hit south and west sides of Houston area.
2022 – Final HCFCD Report on January 8-9, 2022 Storm
Slow moving cold front that dropped 8.5 inches in 24 hours and spawned numerous tornados along a corridor in northern Harris County.
2024 – Final HCFCD Report on April 28 through May 5 Storm
The storm of 20 year rains that produced a 500-year flood on the San Jacinto East Fork. Also include data for other watersheds, putting the storm in historical perspective. See where it ranks vs. other major floods.
2024 – Final HCFCD Report on Hurricane Beryl in July
Cat 1 storm made landfall around Matagorda. Produced highest storm surge since Ike. Brought intense rains, but because of storm’s speed, few homes flooded. However, winds knocked out power to more than 2.2 million people.
Regulations
City of Houston
Houston Floodplain Ordinances (Chapter 19)
Lake Houston (including dredging, excavating and mining) Chapter 23
Houston Planning and Development
Houston Public Works Infrastructure Design Manual Chapter 9 on Stormwater Requirements 2023
Houston Public Works Infrastructure Design Manual – Entire 2023
Houston Public Works General Requirements 2023
Houston Buildings and Neighborhood Protection
Updated as of 10/25/2023
Harris County
Recommendations for Minimum Regulations in Areas Draining into Harris County
Harris County Infrastructure Regulations 2019
Harris County Regulations for Approval and Acceptance of Infrastructure 2023
Harris County Engineer’s Page (check for latest updates)
Montgomery County
Montgomery County Development Regulations (March 4, 2025)
Montgomery County Floodplain Management Regulations
Montgomery County Subdivision Rules and Regulations
Montgomery County H&H Study Analysis Guidelines
Montgomery County Engineering Department
Montgomery County Drainage Criteria Manual – 2019
Montgomery County Draft Drainage Criteria Manual – Feb 2024 Update
Montgomery County Summary of Changes in DCM Update
Montgomery County Steps for Development – Structure in Floodplain
Montgomery County Engineers Page (check for latest rules/regulations)
Liberty County
2021 Liberty County Subdivision and Development Regulations
Liberty County Flood Prevention Ordinance
Liberty County Road Construction Including Ditches
Liberty County Engineer (check for latest rules/regulations)
State of Texas
Harris County Flood Control District
Bond Updates:
Bond Vote Outcome:
Pre-Referendum Project Lists:
Project List for Flood Bond Final as of August 6, 2018
Project List for Flood Bond as of August 1
Project List for Flood Bond as of July 19
Project List for Flood Bond as of June 29
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.
Official Bond Text:
This is what you will actually be voting on. The project list can be changed in the future to give the Flood Control District flexibility to achieve these objectives.
Subdivision Drainage Projects
Subdivision drainage projects used to be a subset of projects within the flood bond. However, Commissioners formally transferred them to the Office of the County Engineer in April 2021. See Item 21-1833 in the 4/27/21 Commissioners Court meeting.
Studies:
HCFCD page with links to studies reporting on different phases.
Kingwood Area Drainage Analysis 2020 Summary
Kingwood Area Drainage Study Volume 1 (Part A – Text of the Full Report)
Kingwood Area Drainage Study Volume 1 (Part B – Maps)
Kingwood Area Drainage Study Volume 1 (Part C – Additional Maps and Cross Sections)
Kingwood Area Drainage Study Volume 2 (Appendices Including Photos & Tables)
Kingwood Diversion Ditch Preliminary Engineering Review
Kingwood Diversion Ditch Typical Cross Section for Alternative #1
Kingwood Diversion Ditch Typical Cross Section for Alternative #2
Kingwood Diversion Ditch Typical Cross Section for Alternative #3
Kingwood Diversion Ditch Bridge Assessment
Kingwood Diversion Ditch Stream Condition Assessment
Kingwood Diversion Ditch Stormwater Detention Basin Alternatives
Kingwood Diversion Ditch Threatened/Endangered Species Habitat Assessment
Kingwood Diversion Ditch Exhibit 1 Project Area
Kingwood Diversion Ditch Exhibit 2 FEMA Map
Kingwood Diversion Ditch Exhibit 3 Historical Flooding
Kingwood Diversion Ditch Exhibit 4 Topographical Map
Kingwood Diversion Ditch Exhibit 5 Land Use Cover
Kingwood Diversion Ditch Exhibit 6 Existing Parcel and Right of Way
Kingwood Diversion Ditch Exhibit 7 Waterlines
Kingwood Diversion Ditch Exhibit 8 Wastewater Lines
Kingwood Diversion Ditch Exhibit 9 Pipelines
Kingwood Diversion Ditch Exhibit 10 Utilities
Kingwood Diversion Ditch Exhibit 11 Stormwater Lines
Kingwood Diversion Ditch Exhibit 12 Inundation Map 50%
Kingwood Diversion Ditch Exhibit 13 Inundation Map 10%
Kingwood Diversion Ditch Exhibit 15 Inundation Map 1%
Kingwood Diversion Ditch Exhibit 14 Inundation Map 0.2%
Huffman Area Drainage Analysis 2019
Covers areas east of Lake Houston including East Fork, Luce Bayou and Cedar Bayou watersheds.
Watersheds in Harris County:
Watersheds and Channels Reference Guide. Contains maps of every watershed and channel in Harris County along with indexes and reference numbers. Useful for determining the extent of water upstream from you.
Hurricane Harvey and Flooding
Remembering Hurricane Harvey – Impact and Response in Harris County
52-Page book published by HCFCD in 2018 as impacts of storm became clear. Non-technical. Written and art directed for general audience. Filled with poignant pictures and informative graphics that emotionally and statistically recreate the impact of the storm and our immediate response to it.
Hurricane-Harvey-Rainfall-Event-Presentation_092817
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.
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).
SJRA Release Rates from Lake Conroe during Hurricane Harvey
From affidavits of Hector Olmos and Chuck Gilman.
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.
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.
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.
San Jacinto River Authority
SJRA/City of Houston Contract for Operation of Lake Conroe
This contract, approved by Houston City Council in September 2023, governs the operation of and releases from Lake Conroe. It stipulates that the City owns two-thirds of the water in the Lake and that the contract remains in effect until the end of the useful life of the Lake. It places a premium on conservation, but provides a force majeure provision for hurricanes and storms. (Section 7.02 page 24). Attachments include historical documents from the TCEQ and Texas Water Commission and SJRA. The last outlines how SJRA accounts for water that it lets lakefront property owners pump out of the lake. 48 pages in total. Important for understanding lake lowering policy in advance of storms.
Lays out the goals and authorities of the SJRA. They include flood control; erosion prevention; reforestation; and protecting life and property.
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.
SJRA and Lake Conroe History
See Chapter 4 of this doctoral dissertation by Andrew C. Baker at Rice University. It paints a fascinating picture of the problems the SJRA had in originally fulfilling its basic mission and how the SJRA overcame them with help from the City of Houston.
SJRA Flood Control Planning Study 1985
Includes recommendations for upstream, regional detention along with their benefit/cost ratios at the time. Comparing this to current studies of the same areas dramatizes the need for revising BCR rules.
Sedimentation in the Upper San Jacinto River Basin has been well documented and is known to impact floodway conveyance capacity. Evaluation of sedimentation in the Upper San Jacinto River Basin, including identification of which sub-watersheds in the basin produce and store the most sediment, prioritization of individual watersheds/locations for improvements, and development of conceptual sedimentation solutions.
San Jacinto River Sediment Removal and Sand Trap Development 2022
By Freese & Nichols. Explores the feasibility of implementing sediment trapping facilities (“sand traps”). The purpose: to remove sediment from the West or East Fork of the San Jacinto River.
FAQs-Related-to-Harvey-and-Lake-Conroe-Dam
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 Release Rates from Lake Conroe during Hurricane Harvey
From affidavits of Hector Olmos and Chuck Gilman.
Appellate Court Decision in SJRA “Takings” Case
Downstream homeowners allecged that SJRA took their homes without just compensation when it released 79,000 CFS from Lake Conroe during Harvey. Trial court found for the plaintiffs. Appellate court dismissed the claims.
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.
Sedimentation
Problems
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.
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.
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.
Dredging
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. However, please note that there have been amendments to this document. The first increased the amount to be dredged by more than 2X. The second made a minor adjustment to expand dredging to a river access point for dredging equipment. Here is the Corps’ West Fork Value Engineering Study from May 7, 2018, that accompanied these plans. Caution: large downloads, may be slow to open because of large numbers of visuals.
The Case for Expanding the West Fork Dredging Project Scope
Same as listed above under sedimentation problems. 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.
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.
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.
Sedimentation in the Upper San Jacinto River Basin has been well documented and is known to impact floodway conveyance capacity. Evaluation of sedimentation in the Upper San Jacinto River Basin, including identification of which sub-watersheds in the basin produce and store the most sediment, prioritization of individual watersheds/locations for improvements, and development of conceptual sedimentation solutions.
San Jacinto River Sediment Removal and Sand Trap Development 2022
By Freese & Nichols. Explores the feasibility of implementing sediment trapping facilities (“sand traps”). The purpose: to remove sediment from the West or East Fork of the San Jacinto River.
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
Using new technology, previous reports were re-evaluated. Indicates Lake Houston has lost capacity at an average of 384 acre-feet per year since impoundment. Recommended new hydrographic survey be completed every five years. Original capacity was 158,553 acre feet. In 2018 it was 136,119 acre feet.
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.
Other Flood Mitigation
Harris County Community Flood Resilience Task Force Bylaws – A group formed after Harvey to give voice to the diverse concerns within Harris County about flooding and flood mitigation efforts.
Report on National Flood Insurance Program and recommended changes.
FEMA Hazard Mitigation Assistance Cost Sharing Guide
Compares cost sharing percentages for different types of grants.
Buffalo Bayou and Tributaries Resiliency Study 2020
Feasibility study of the Buffalo Bayou and Tributaries flood risk management system.
Region 6 San Jacinto Flood Planning Group
Recommendations for first state flood plan.
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.
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.
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.
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.
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.
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.
System Capacity Maps for all 23 Harris County Watersheds
Pre-Atlas 14 maps show how much rainfall streams and their tributaries can handle without flooding.
Tax Appraisals
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.
Congressional Budget Office Reports on Flooding
The reports below represent the Congressional Budget Office’s recent work on flooding and natural disasters. They are authored by Evan Herrnstadt, Ph.D., Principal Analyst, Microeconomic Studies Division. These reports each provide data for public policy makers on a different aspect of flooding.
Climate Work provides an overview of several different studies and presents key findings.
Effects of Flood Damage on the Subsidy Cost of Federally Backed Mortgages. Uses data on mortgages and expected flood damage for each residential property in the United States to examine how much flood damage is expected to increase the cost of federally backed mortgages (referred to as the subsidy cost).
Flood Insurance in Communities at Risk of Flooding. Examines how properties at risk of flooding share the cost of NFIP policies across communities with different economic and demographic characteristics.
Climate Change, Disaster Risk, and Homeowner’s Insurance. Analyzes recent changes in property insurance markets and considers alternative insurance products as well as policy approaches to increase the availability and affordability of insurance for homeowners and renters.
Flood Damage and Federally Backed Mortgages in a Changing Climate. Estimates how much flood damage homes with federally backed mortgages are expected to face in two multiyear projection periods, one centered on 2020 and the other centered on 2050.
Communities at Risk of Flooding. Examines how projected flood risk varies across communities with different economic and demographic characteristics in two multiyear projection periods, one centered on 2020 and the other centered on 2050.
FEMA’s Disaster Relief Fund: Budgetary History and Projections. Deals with budgetary issues past and present in the face of irregularly occurring disasters.
Army Corps of Engineers: Budgetary History and Projections. Explains the Corps’ purpose, scope of operations, and how Congress has budgeted allocations for it.
Flood Damage Avoided by Potential Spending on Property-Level Adaptations. Provides an estimate of the potential damage avoided from spending by governments and homeowners on property-level flood risk adaptations, primarily buyouts and elevations.