F-14 General Drainage Improvements Near Kingwood

F-14 General Drainage Improvements Near Kingwood

Last Modified: 10/20/2020 09:32 PM

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Virtual Community Engagement Meeting

You are invited to participate in a virtual public meeting to learn more about this project.

Date: Tuesday, October 20, 2020
Time: 6:30 p.m. to 7:30 p.m.
Join online: PublicInput.com/Kingwood
Join by phone: 855-925-2801 (Meeting Code: 9541)

Recent Actions

September 15, 2020 – Harris County Commissioners Court authorized Harris County Real Property Division to sign an earnest money contract in the amount of $14,019,316 for the purchase of two tracts of land containing approximately 267.35 acres in Montgomery County for the Woodridge Village stormwater detention basin, with purchase of the property being contingent upon certain conditions and commitments.

May 19, 2020 – Harris County Commissioners Court approved updates to project details in the 2018 Bond Program List. Update corrects precinct information from Precinct 2 to Precinct 4.

August 13, 2019 - Harris County Commissioners Court authorized a $700,000 agreement with an engineering firm for engineering services in support of this project. Neel-Schaffer, Inc., in the amount of $700,000 for engineering services to identify flooding sources and develop potential flooding solutions in the Kingwood area in Precinct 4 (Map ID F-14, Project ID Z100-00-00-P027, UPIN 190900Z1P027).

August 13, 2019 - Harris County Commissioners Court approved a contract with Neel-Schaffer, Inc. to begin the Kingwood Area Drainage Analysis.

June 25, 2019 – Harris County Commissioners Court authorized negotiations with an engineering firm to identify flooding sources and develop potential solutions in the Kingwood area.

June 4, 2019 – Harris County Commissioners Court authorized an agreement with the Lake Houston Redevelopment Authority/Tax Increment Reinvestment Zone No. 10 to conduct an evaluation of channel capacities and possible improvements within Kingwood, with no Flood Control District funding required.

March 26, 2019 – Harris Harris County Commissioners Court authorized negotiations with the Lake Houston Redevelopment Authority in support of this project

October 23, 2018 – Harris County Commissioners Court authorized and initiated this project

Project Description

The Harris County Flood Control District (Flood Control District) and the Lake Houston Redevelopment Authority (TIRZ 10), City of Houston, teamed together to conduct a drainage study for the streams within the greater Kingwood area (Study Area). The Kingwood Study (Kingwood Drainage Analysis) identified the level-of-service (LOS) within the existing open channel drainage infrastructure and developed improvement options to obtain a 1 percent annual chance event (100 year). This equates to 13 to 18 inches of rainfall within a 24 hour period LOS, for open channels throughout the Study Area. A 100-year channel LOS is defined as achieving no damages to man-made structures from overbank flooding during a 1 percent annual chance (100-year) rainfall event or 13 to 18 inches of rainfall within a 24-hour period. An interlocal agreement between the Flood Control District and the Lake Houston Redevelopment Authority TIRZ 10 (Agreement No. 2019-153), was completed to perform the Kingwood Study and to develop the Kingwood Plan.

The purpose of the Kingwood Plan was two-fold:

  1. Evaluate the Study Area and quantify the existing flooding problems along the streams, channels, and ditches, as well as identify drainage issues associated with the local (storm sewer system) drainage infrastructure within the Study Area; and
  2. Develop strategies to improve the open channel portion of the drainage infrastructure to achieve a 1 percent annual chance event (100-year) level of service that will minimize flood damages to structures within the Study Area. The results of the analysis formed the Kingwood Plan.

The scope of the Kingwood Study began with the study of five streams named in the interlocal agreement:

  1. Bens Branch (Flood Control District Unit G103-33-00), from 3,500 feet upstream of Kingwood Drive to 2,000 feet downstream of West Lake Houston Parkway
  2. Flood Control District Unit G103-33-01
  3. Kingwood Diversion Ditch (Flood Control District Unit G103-38-00)
  4. Green Tree Ditch (Flood Control District Unit G103-80-01)
  5. Taylor Gully (Flood Control District Unit G103-80-03.1B)

In addition to these five channels studied as part of the interlocal agreement, the Flood Control District opted to study all the remaining open channels within the Study Area, regardless of ownership.

Kingwood Drainage Analysis

Technical Report Summary – Updated 10.20.2020

Flood Risks in the Study Area

The roads in the Kingwood area are part of the Kingwood drainage network and many of these roads were purposely designed to move stormwater. The concept of building low roads and elevating houses was a development strategy used as late as the 1990s. Today, development criteria for roads only allow for ponding of approximately 1 foot deep. A modern design will require the developer to design a path where excess rainfall runoff can drain out of a neighborhood without flooding structures.

In Kingwood, there are generally no planned extreme event sheet flow paths, so when rainwater exceeds the capacity of the storm sewer system, which is generally between 1 to 2 inches per hour, street ponding will occur. If extreme event sheet flow paths were to be designed, they would need a channel or bayou with the appropriate capacity to be able to handle the additional flows. So, the first step in the process to reduce flooding in the Kingwood area must begin with improving the bayou and channel network, which is the focus of the Kingwood Plan.

Types of Flood Risk

Sheet flow is the movement of shallow runoff across the ground during a rainfall event as the runoff makes its way to the drainage system or river.

Riverine flooding occurs when a river or channel overflows its banks. River flooding can be a result of both intense bursts of rainfall and long duration rainfall events.

Lake flooding occurs when a lake exceeds its maximum water surface elevation.

Study Recommendations

Based on the results of the Study, the Flood Control District is recommending that proposed improvements to the Kingwood Diversion Ditch and Taylor Gully move to preliminary engineering so that a Preliminary Engineering Report can be completed subject to input from Kingwood area residents. Additionally, the Flood Control District recommends that the proposed improvements to Taylor Gully be reanalyzed to determine how the use of Woodridge Village for detention could modify the recommended improvements. These improvements were determined based on necessary sequencing and project benefits.

Recommended Projects Map

Next Steps

To move forward, a detention mitigation plan will need to be developed and implemented for Bens Branch, the Kingwood Diversion Ditch, and Taylor Gully. The detention mitigation plan will also need to account for the recommended improvements to the tributaries of Bens Branch and the Kingwood Diversion Ditch.

The Flood Control District recommended that the improvement options be constructed and implemented in a phased approach from downstream to upstream. This approach will help to ensure that the receiving systems have the necessary capacity without some form of flow restriction which limits the benefit of the constructed improvements and does not result in downstream impacts during construction. Additionally, the improvement options for the tributaries to Bens Branch and the Kingwood Diversion Ditch cannot be constructed until the improvements to Bens Branch and the Kingwood Diversion Ditch have been constructed. Similarly, local drainage improvements cannot be constructed until after the detention mitigation plan and recommended improvements have been implemented for the receiving channel.


The Harris County Flood Control District has a significant number of flood damage reduction projects occurring all over Harris County as part of its on-going Capital Improvement Program (CIP), Operations and Maintenance, and the 2018 Bond Program. Click the Project ID on the Map to learn about projects’ details. Some early-stage projects are not highlighted on the map. The map will be updated when projects advance or when more information becomes available.

Location

The Study Area is the part of the Kingwood community within Harris County. The Study Area is bounded by the West Fork of the San Jacinto River to the west and south and by White Oak Creek and the East Fork of the San Jacinto River to the east. Being a master planned community, Kingwood is mostly residential with typical suburban infill of commercial, public, and some industrial land uses. Parks and golf courses provide green space to the community. The upper and western portions of the Study Area were developed within the past 35 years with the remaining area developing more recently. The Study Area encompasses 21.7 square miles and is drained by numerous streams and man-made channels. This area can be impacted by out-of-bank channel flooding, overland (sheet) flow, and storm sewer capacity limitations overloaded by intense rainfall events.

Stage

The Kingwood Area Drainage Analysis is currently in the feasibility study stage.

Learn more about the Project Lifecycle

Bond Project Listing

Community Engagement Meetings

Previous meeting information will be posted here following each meeting.