Water Designated Uses Quality Contact Recreation • Limited Quality Aquatic Habitat Monitoring Agencies City of Houston Health and Human Services City of Houston Public Works and Engineering (historical) RHEINHARDT BAYOU Texas Natural Resource Conservation Commission United States Geological Survey (flow) GARNERS BAYOU 1 GREENS BAYOU Dissolved oxygen, water temperature, and bacteria LAKE Sam Houston Tollway HOUSTON levels are critical factors that impact aquatic life. These charts show the actual value of water samples taken between 1994-1999. I-45 Oxygen in the water is important to aquatic I-59 life. Generally, dissolved Fig. 1 oxygen levels are con- SHELDON sidered good for aquatic RESERVOIR organisms at 5mg/l HALLS BAYOU (or higher). Fish popu- lations can still be supported, although mg/L stressed, at levels as colonies/ °C Flood Control low as 3 mg/l. 100mL Throughout the watershed the temper- Before extensive development occurred throughout Sam Houston Tollway Temperature affects ature dissolved oxygen relationship the watershed, Greens Bayou had a relatively small 2 the quality of aquatic appears to be satisfactory. Dissolved channel with tree-lined banks and tight meanders. During flood life and also dictates oxygen readings are adequate for events, water would pond in forested and grassy areas and slowly the amount of oxygen survival of aquatic populations in the infiltrate into the soil. Hwy. 90 SPRING GULLY that can be contained 1 upper and middle sections of the in water. watershed. However, in the lower As residential development increased impervious cover, reducing In the 1990’s, other more reaches of the bayou, these levels dip infiltration and accelerating runoff, physical modifications to the channel “environmentally friendly” types of flood Coolgreen Bacteria counts are below the levels that support healthy to control flooding became a necessity. Individuals first dug ditches from damage reduction measures were implemented. Corridor important in assessing fish habitation. There is substantially suburbs to the bayou to reduce flooding problems, but these efforts soon The Harris County Flood Control District constructed a waterbody’s suitability Fig. 2 more urban development in the middle became inefficient and more substantial modifications were required to a large detention structure and a wetlands mitigation for contact recreation, and lower portions of the watershed, effectively protect the surrounding communities. bank (1450 acres) near John Ralston Road to provide temporary flood such as swimming. resulting in polluted stormwater runoff, water storage. Smaller detention basins were also created along the Fecal coliform densities which can cause lower oxygen levels. Major modifications below US HWY 59 began in 1973, and modifications bayou and its tributaries. Water is detained in these basins until the below 200 colonies/ in the upper reaches of the bayou began in the early 1980’s. With floodwaters recede and the bayou can accommodate added water. 100 ml of water are Although the stations in the middle these modifications, the bayou’s physical nature was compromised. Since these structures do not affect the bayou during non-flooding GOODYEAR CREEK considered acceptable. and lower portions of the watershed The bayou’s meanders and bends were straightened, the cross-sections events, aquatic and aesthetic properties are minimally affected. exhibit a stable or slightly decreasing were enlarged, and portions of its banks were paved. Although this 1 = Monitoring Site trend in dissolved oxygen values, the colonies/ increased hydraulic capacities, aquatic habitat was degraded due to The District, in cooperation with other federal, state, and local agencies, mg/L °C 100mL station located in the upper portion of reduction of near-stream vegetation (shade cover) and pool and riffle is also active in purchasing homes and other buildings that are frequent- i-10 the watershed shows a significant sequences, which provide diverse aquatic habitat. ly inundated during flood events. This “buyout” program has been quite = Detention Basin Fig. 1 decline in oxygen levels since 1994. Fecal coliform densities successful in Harris County, with several hundred homes having been 3 during the time frame Continued development in the upper purchased in the last decade. Participants are given fair-market value for represented were all within portions of the watershed could their property and may receive assistance in relocating. Flood-prone reportable limits. 2 continue this trend. structures are then removed, resulting in reduced flood losses. Fig. 2 Fecal coliform densities Bacteria counts throughout the water- Since flooding problems are not always the result of activities or land on 11/6/97, 12/3/97, and shed are well above contact recreation 1/7/98 were reported as uses in close proximity to a large waterbody, the District also purchases standards at each station. Typically, >160,000 colonies/100 ml; available land outside the floodplain. Depending on the landscape and To Houston Ship Channel densities on 9/2/99 were Fig. 3 these densities are higher after land use, any part of a reported as >200,000 rainstorms, which wash bacteria from watershed can be inundated colonies/100 ml. many sources into area waterways. with water as it makes it way Fig. 3 Fecal coliform numbers generally to the major drainage channel Fecal coliform densities decline rapidly after a rainfall unless on 5/4/95 and 12/6/95 during a heavy rain event. were reported as <200 there is a continuous source of bacteria Thus, watershed planning colonies/100 ml; densities present, such as a leaking septic tank in terms of flood damage on 1/7/98 were reported as or sewer line. reduction is essential in >160,000 colonies/100 ml. colonies/ protecting lives and property mg/L °C NOTE: 100mL Degree of development also impacts in a drainage basin/watershed. Trend lines do not the amount of bacteria present as necessarily correspond to actual values on the evidenced by the higher fecal densities y-axis. The slope of the in the lower portions of the watershed. trend lines exhibit the best-fit line and indicate either increasing, 3 decreasing, or no change in the corresponding para- meter over time plotted. Watershed G r The Greens Bayou watershed is wholly contained Profile No matter where e ed e ersh within Harris County and is a part of the lower Area 213 Sq. Miles ns B u Wat San Jacinto River Basin. Greens Bayou is the largest ayo tributary to Buffalo Bayou and the Houston Ship we live or work, G Rainfall Average Annual 46" Channel. Its watershed contains portions of the Coolgreen Corridor Local Residents Get Involved Elevation 20'-134' we are always r City of Houston as well as unincorporated residential The “Coolgreen Corridor” is land set aside to reduce flood damage, but is primarily intended to be a nature e areas and undeveloped brushland. d Geology Sedimentary formations preserve. The corridor connects Herman Brown Park with Greens Bayou, approximately 1.5 miles north of e consisting of materials h in a watershed – Interstate 10 in Houston. Currently, there is no official entrance to the preserve; however, visitors can e s deposited by water r access the corridor’s nature trails through a vacant lot on Pecan Grove Drive off of Coolgreen Avenue. n te Vegetation Coastal short grass prairie s a an area of land The movement to acquire the original 23-acre strip of land began in 1989 after several severe flooding W (predominant) Bayou events damaged residents’ homes. Previously, in anticipation of the completion of the NE segment of Pine-hardwood forest that drains to a Beltway 8, the Harris County Flood Control District dug ditches to alleviate flooding problems associated Soils Clay and silt, locally sandy with the highway development. The beltway was completed before detention basins could be put in, and Poorly drained stormwater from the ditches increased flow in the bayou, resulting in increased flooding problems to High moisture retention at particular creek, homes downstream. the surface Some areas with higher river, bayou or Almost a decade later, a conservation investor donated money through the Brown Foundation, allowing permeabilities serve as the land to be purchased and donated to the Houston Parks Board, and, finally, to the City of Houston. aquifer recharge zones The sale included a deed restriction requiring that the land not be developed under any circumstances. lake. As our Since that acquisition, two private landowners and Texaco USA have donated adjacent land, expanding Major Ecoregion Western Gulf Coastal Plain the corridor to over 50 acres. Currently, members of the Legacy Land Trust are contacting other property owners, mainly those with flood-prone property, in an effort to enlarge the corridor further. Their visions Cities Houston population grows, include expanding the strip to Sheldon State Park, creating a continuous wildlife corridor and refuge Humble between Herman Brown Park and Sheldon State Park. Tributaries Halls Bayou so do the risks Garners Bayou Projects involving public and private entities are extremely important when attempting to preserve or clean up the environment. When these groups Spring Gully are able to work together, partnerships can be established with multiple benefits for all involved. The Coolgreen Corridor is a prime example of a project Big Gulch to our waterways that benefits a variety of local interests as well as maintains the health of the environment. The Coolgreen Corridor serves to enhance aesthetics of the Goodyear Creek waterway and surrounding neighborhoods, to filter runoff and enhance water quality, and to reduce flooding. The land includes specific designated sites for bird habitat, and preserves a contiguous corridor in which migratory animals can move, enhancing the diversity of species and enriching the habitat. Aquifers Gulf Coast from activities in In addition, people can experience nature in the middle of a highly urban area while learning about the bayou ecosystem. Issues Flooding/high moisture History retention at surface due the watershed.