Greens Bayou WatershedFACT SHEET: Watershed Overview

October 2011

The Greens Bayou watershed is located in north Harris County and encompasses parts of the cities of Houston and Humble. A watershed is a geographical region that drains to a common bayou, creek or other waterway. Greens Bayou flows from its headwaters in the northwest part of Harris County near Jones Road to the east and south where it eventually meets the Houston Ship Channel. Greens Bayou is 43 miles long and the watershed covers approximately 212 square miles. In addition to Greens Bayou, the watershed includes three primary waterways: Garners Bayou, Reinhardt Bayou and Halls Bayou. High-density development in the watershed’s floodplains has led to high damages to homes, businesses and vehicles during frequent flood events over the past several decades. Additionally, storm surges can contribute to flooding along the lower 10 miles of the bayou.

COMPLETED CAPITAL PROJECTSGarret Road Stormwater Detention Basin (P500-01-00): The Garret Road Stormwater Detention Basin is located on a 1,529-acre site located near Tidwell Road and John Ralston Road and was completed in 1998. Garners Stormwater Detention Basin (P500-03-00): The Garners Stormwater Detention Basin is located on a 168-acre site near the confluence of Greens and Garners bayous. The first phase of excavation was completed in 2008. The second and final phase of the project has been designed.

CAPITAL PROJECTS IN PROGRESSGreens Bayou Federal Flood Damage Reduction Project (P100-00-00-PG001): The Greens Bayou Federal Flood Damage Reduction Project is a partnership between the U.S. Army Corps of Engineers (Corps) and the Harris County Flood Control District. Under the Corps’ leadership, a reevaluation of alternatives for flood damage reduction projects has recently been completed.

For more information on Harris County’s watersheds, go to: hcfcd.org/watersheds.html or call 713-684-4000.

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Drainage Area

211 Sq. Miles 528,720 308 Miles 43 Miles

Watershed Population Open Stream Miles Length of Halls Bayou

Greens Bayou WatershedFACT SHEET: Watershed Overview

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Features of the recommended project include 3.7 miles of earthen channel modifications from Cutten Road to Veterans Memorial Boulevard; a stormwater detention basin and appropriate environmental mitigation. The Corps is designing the stormwater detention basin at Greens Road and Antoine Drive in northern Harris County. Further design and construction await funding.

Greens Bayou Mid-Reach Flood Damage Reduction Plan (P100-00-00-Y018): The Greenspoint Management District created a task force after Tropical Storm Allison (2001) to identify a local project along Greens Bayou to reduce flooding damages. The Greens Bayou Mid-Reach Flood Damage Reduction Plan is a product of that effort. The plan includes widening 11 miles of Greens Bayou from John F. Kennedy Boulevard to Veterans Memorial Drive, constructing of four stormwater detention basins and modifying 19 bridges. The four stormwater detention basins identified by the plan are the Aldine-Westfield Stormwater Detention Basin (P500-04-00) located at Aldine Westfield Road and Beltway 8; the Glen Forest Stormwater Detention Basin (P500-08-00) located north of Greens Bayou and east of IH-45; the Kuykendahl Stormwater Detention Basin (P545-01-00) located south of Kuykendahl Road and east of Ella Boulevard; and the Lauder Stormwater Detention Basin (P500-06-00) located at Lauder Road and Long Oak Drive. Preliminary excavation has begun on the Aldine-Westfield, Lauder and Kuykendahl Stormwater Detention Basins. Further engineering services and construction are not currently funded.

STORMWATER DETENTION BASINSExcavation or construction is in progress at six stormwater detention basins in the Greens Bayou watershed. Three of the stormwater detention basins currently under construction are:

Cutten Road Stormwater Detention Basin (P500-02-00): The Cutten Road Stormwater Detention Basin is located on a 236-acre site near Cutten Road and Hwy 249. The majority of the site south of Greens Road has been excavated. A project is planned to excavate part of the stormwater detention basin north of Greens Bayou. An Interlocal Agreement has been signed with Harris County for Hollister Road to bisect this site.Glen Forest Stormwater Detention Basin (P500-08-00): The Glen Forest Stormwater Detention Basin is located on a 160-acre site north of Greens Bayou and east of IH-45. Right-of-way acquisition and utility relocation are complete. As of October 2011, final design services were being negotiated and construction awaits availability of funds. A grant application has been submitted to the Federal Emergency Management Agency (FEMA) under a Hurricane Ike Hazard Mitigation Grant Program (HMGP) to secure matching federal funds and move forward with construction.Kuykendahl Stormwater Detention Basin (P545-01-00): The Kuykendahl Stormwater Detention Basin is located on a 293-acre site on the North Fork of Greens Bayou, south of Kuykendahl Road and east of Ella Boulevard. A part of the stormwater detention volume in this basin is designated as mitigation for specified development in the area. A grant application has been submitted to FEMA under a Hurricane Ike HMGP to secure matching federal funds and move forward with construction.Greens Bayou Wetlands Mitigation Bank In 1995, the Flood Control District implemented one of the first wetlands mitigation banks in Harris County. Mitigation banks provide sustainable ecological benefits in advance of unavoidable adverse impacts to wetlands caused by human activity. The 1,400-acre mitigation bank, which is located near the confluence of Greens and Garners bayous, provides compensating wetlands credits for projects that cannot avoid disturbing wetlands. Currently, public entities are given the opportunity to pay a one-time fee to purchase credits from the bank to satisfy all or part of their statutory wetland mitigation requirements. The mitigation bank combines wetland creation, mitigation and natural stormwater runoff treatment in a unique and highly beneficial manner.