Harris County Flood Control District
COASTAL PRAIRIE MANAGEMENT
PLAN
for
Willow Waterhole Detention Basin
(HCFCD Unit No. D512-01-00)
Version 3.0
March 2015
Record of Changes
Version Revision Section/ Initials
Number
Date
Page
1.0
11/13/13
ALL
CW/SB Document Finalized.
2.0
4.2 / 10
1/17/2014 5.2 / 15
6.5 / 16
Description
Update Tree Clearing information.
SB/CW Updated information regarding fencing of H. texana sites.
Insert Fencing section under Trails and Signage
Updated maps with 2014 aerials
3.0
3.7 / 8
4.2 / 11
4.4 / 12
Fig. 2
2/26/2015 Fig. 3
Appx B
Appx C
Appx D
Appx E
Ecological Indices added to Appendix B
Link to Public Access Plan added to Appendix C
Updated H. texana monitoring plan in Appendix D
SB
Forested Buffer tree planting photo added to Appendix E
Updated information about tree removal and motte creation in
MU 1, 2, & 3, and future work of MU 4
Updated information about invasive tree removal and native
tree planting within forested buffer
4.0
5.0
6.0
7.0
8.0
9.0
10.0
11.0
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
20.0
21.0
22.0
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Version 3.0
Table of Contents
1.0
Overview ........................................................................................................................................... 1
1.1 Willow Waterhole............................................................................................................................... 1
1.2 Coastal Prairie Management Goals & Objectives .............................................................................. 1
1.3 Plan Purpose and Need ....................................................................................................................... 2
1.4 Plan Use and Updates ......................................................................................................................... 2
2.0
Management Framework .................................................................................................................. 4
2.1 Introduction ........................................................................................................................................ 4
2.2 HCFCD Mission ................................................................................................................................. 4
2.3 NEPA Compliance ............................................................................................................................. 4
2.4 Basin Design ....................................................................................................................................... 5
2.5 Vegetation Management ..................................................................................................................... 5
3.0
Site Description ................................................................................................................................. 6
3.1 Introduction ........................................................................................................................................ 6
3.2 Soils .................................................................................................................................................... 6
3.3 Management Units.............................................................................................................................. 7
3.4 Coastal Prairie..................................................................................................................................... 7
3.5 Wet Coastal Prairie ............................................................................................................................. 7
3.6 Hymenoxys texana .............................................................................................................................. 7
3.7 Forested Buffer ................................................................................................................................... 8
4.0
Coastal Prairie Habitat Management .............................................................................................. 10
4.1 Introduction ...................................................................................................................................... 10
4.2 Tree Removal ................................................................................................................................... 10
4.3 Undesirable Plant Control ................................................................................................................ 11
4.4 Motte Establishment ......................................................................................................................... 12
4.5 Native Plant Transplanting ............................................................................................................... 12
4.6 Mowing............................................................................................................................................. 12
4.7 Transect Monitoring ......................................................................................................................... 13
4.8 Long-Term Maintenance .................................................................................................................. 13
5.0
Texas Prairiedawn (H. texana) Management .................................................................................. 15
5.1 Introduction ...................................................................................................................................... 15
5.2 Operations......................................................................................................................................... 15
5.3 Monitoring ........................................................................................................................................ 16
6.0
Trails & Signage ............................................................................................................................. 17
6.1 Introduction ...................................................................................................................................... 17
6.2 Trails ................................................................................................................................................. 17
6.3 NMZ Signs ....................................................................................................................................... 17
6.4 Interpretive Signs .............................................................................................................................. 17
6.5 Fencing ............................................................................................................................................. 17
HCFCD Coastal Prairie Management Plan
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Version 3.0
Table of Contents, continued
7.0
Communications and Community Relations .................................................................................. 19
7.1 Introduction ...................................................................................................................................... 19
7.2 Public Education ............................................................................................................................... 19
8.0
References ....................................................................................................................................... 20
Figure 1
Figure 2
Figure 3
Figure 4
Conceptual Willow Waterhole Detention Basin Complex Plan ................................................... 3
Willow Waterhole Coastal Prairie Management Area ................................................................. 8
Willow Waterhole Coastal Prairie Management – Monitoring Transects and H. texana.......... 13
Perimeter Signage ....................................................................................................................... 17
Table 1
Example Mowing Regime .......................................................................................................... 12
APPENDICES
Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Coastal Prairie Management Area Plant Inventory
Transect Monitoring Data
Willow Waterhole – Compartment 3 Detention Basin Plan;
Public Access Plan
Hymenoxys texana Monitoring Plan
Site Photographs
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
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Version 3.0
1.0 Overview
1.1
Willow
Waterhole
The Willow Waterhole (WWH) Detention Basin complex, located within the
Brays Bayou watershed in southern Harris County, is owned and operated by
Harris County Flood Control District (HCFCD). It is being constructed as part
of Project Brays, a US Army Corps of Engineers (USACE) flood damage
reduction project. The complex includes six (6) compartments as shown in the
conceptual basin plan, Figure 1. The detention basin properties were acquired
by HCFCD to reduce flood damage risks within the Brays Bayou watershed.
The entire complex is approximately 280 acres and has capacity to store
approximately 1,865 acre-feet of flood water.
The 15-acre Coastal Prairie Management Area is located north and south of a
pipeline corridor within Compartment 3, located east of S. Post Oak Blvd.
Through site investigations, the federally-listed, endangered plant species,
Texas prairiedawn (Hymenoxys texana) was discovered and several remnants
of native coastal prairie habitat were identified.
1.2
Coastal Prairie
Management
Goals &
Objectives
The coastal prairie is an ecosystem of essentially flat, predominantly treeless
landscape dominated by tall grasses, ranging from southwestern Louisiana to
south-central Texas along the Gulf of Mexico. The coastal prairie ecosystem
once covered as much as 9 million acres, however 99% of this land has been
lost to agriculture or urbanization. The remainder is severely threatened by
exotic species and urban sprawl (USGS, 2000).
Historic aerial photography and property ownership documents reveal that the
Coastal Prairie Management Area persisted as a coastal prairie ecosystem as
recently as the late 1980’s. Light grazing pressure excluded woody species
encroachment, even as urbanization surrounded the site. However over the
past twenty-five years, grazing has discontinued and the site has been left
fallow. This allowed larger woody species, dispersed from adjacent urban
areas, to establish a canopy and shade out the understory prairie species.
Removing the encroached woody canopy will restore sunlight to the prairie
floor, providing the germination cues needed to activate the persistent soil
seedbank of the recently displaced prairie species.
This Coastal Prairie Management Plan (Plan) describes activities that will
maintain and enhance native coastal prairie habitat, including the federally
endangered Texas prairiedawn (H. texana) populations within the WWH
Coastal Prairie Management Area.
Continued on next page
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1.0 Overview, continued
1.2
Coastal Prairie
Management
Goals &
Objectives
(continued)
Specific management objectives are to:
 Provide a coastal prairie conservation area for community benefit;
 Expand isolated remnants of native coastal prairie;
 Sustain and possibly enhance existing colonies of H. texana;
 Partially fulfill HCFCD’s mitigation requirements of the National
Environmental Policy Act (NEPA), as documented in the
Environmental Assessment Report;
 Employ adaptive management principles and techniques.
1.3
Plan Purpose
and Need
This Plan is provided to HCFCD personnel, resources agencies, and interested
parties to generally guide maintenance and operations of the WWH Coastal
Prairie Management Area. The Plan specifies activities to ensure
conservation, protection and enhancement of resources, including:
 Coastal prairie and wet coastal prairie;
 Texas prairiedawn (H. texana);
 Natural buffers;
 Public use facilities; and
 Communications
1.4
Plan Use and
Updates
This Plan relies on principles of adaptive management, allowing HCFCD to
respond to changes in the coastal prairie ecosystem and to account for
significant variations in climatic or other environmental factors. Iterative
adaptation of prairie management may also be required to address changes in
management objectives.
This Coastal Prairie Management Plan provides adaptive management by:
 Revisiting and revising management objectives, regularly;
 Using system models as reference;
 Incorporating development in prairie management research;
 Developing a range of management choices;
 Assessing and evaluating outcomes;
 Incorporating assessment results; and
 Adjusting management techniques, as needed, to account for
significant variations in climatic or other environmental factors.
HCFCD Environmental Services Division (ESD) will prepare and update this
Plan based on assessment outcomes and through input from HCFCD
Department and Project Managers, resource agencies, and other parties.
Updates to this final Plan are documented in the Record of Changes, found in
the front of this document.
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
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Version 3.0
Figure 1. Conceptual Willow Waterhole Detention Basin Complex Hydrology Plan
(not for construction purposes)
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
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Version 3.0
2.0 Management Framework
2.1
Introduction
This section provides context for operations and maintenance of the WWH
Coastal Prairie Management Area with respect to:
 HCFCD Mission Statement;
 National Environmental Policy Act (NEPA) Compliance;
 Basin Design; and
 HCFCD Vegetation Management Contracts
2.2
HCFCD
Mission
The HCFCD was created as a local partner for major federal flood damage
reduction projects, such as Project Brays, which includes construction of the
WWH Detention Basin. Since its creation, HCFCD has developed
increasingly complex roles, as outlined in the mission statement to:
Provide flood damage reduction projects that work, with appropriate regard
for community and natural values.
2.3
NEPA
Compliance
After passage of Section 211 of the Water Resources Development Act
(WRDA) of 1996, the HCFCD was given the opportunity to perform the
General Reevaluation Report (GRR) studies at WWH, which included the
preparation of the Environmental Assessment (EA) (HCFCD, 2008). Both the
EA and the GRR were completed and signed off in March 2008.
As partially funded by the US Army Corps of Engineers (USACE),
construction of the WWH Detention Basin must comply with NEPA. This
Coastal Prairie Management Plan is consistent with the mitigation
commitments outlined in the EA and Biological Assessment (BA) (HCFCD,
2007). Essential concepts of this Management Plan, consistent with the BA,
include:
 Preserving a minimum 200-foot buffer around the current H. texana
populations (later revised to allow a 100-foot buffer in select areas);
 Fencing off existing H. texana colonies and annual removal of woody
vegetation encroaching upon the H. texana buffer;
 Planting of native grasses and wildflowers such as little bluestem, big
bluestem and gamma grass in the northern portion of the basin
adjacent to the prairie buffers to control the spread of Bermuda grass
or other encroaching vegetation with the ability to displace prairie
species;
 Cleaning of all mowing equipment prior to use to reduce the spread of
invasive species within the buffer areas;
Continued on next page
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2.0 Management Framework, continued
2.3
NEPA
Compliance
(continued)





Establishing a 15-acre coastal prairie conservation area through
conservation of remnant coastal prairie areas and restoration of
historic coastal prairie areas by selective removal of any encroaching
vegetation with the ability to displace prairie species;
Excluding the 15-acre coastal prairie conservation area from basin
operations;
Scheduled mowing, including within H. texana sites, twice annually;
Annual monitoring and reporting of plant density, aerial coverage, and
reproductive success for the existing H. texana colonies to both
USFWS and USACE; and
Adjustment of management techniques as needed to account for
significant variations in climatic or other environmental factors.
2.4
Basin Design
The WWH Detention Basin compartment located adjacent to the Coastal
Prairie Management Area (Compartment 3) is currently being designed to
avoid impacts to the coastal prairie and H. texana habitats. A copy of the
proposed basin design is provided in Appendix C.
2.5
Vegetation
Management
HCFCD Environmental Services Division (ESD) has removed the WWH
Coastal Prairie Management Area from HCFCD’s cyclic mowing contract
and maintenance, placing it in a No Maintenance Zone (NMZ). ESD uses its
Term Contract for Sensitive Habitat Maintenance, to manage resources within
the NMZ. ESD’s sensitive habitat maintenance contractor uses specialized
methods to manage the coastal prairie habitat, as outlined in this Plan (Section
4.0).
ESD also utilizes its Term Contract for Thick Sod Cutting and Relocating of
Vegetation to enhance the Coastal Prairie Management Area.
HCFCD Coastal Prairie Management Plan
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3.0 Site Description
3.1
Introduction
This Plan addresses the existing conditions and future plans for Compartment
3 of the WWH Detention Basin complex and specifically the Coastal Prairie
Management Area, located north and east of the future detention basin site, as
conceptually shown in Figure 1.
The primary purpose of the WWH Detention Basin is to mitigate flood events
from Brays Bayou; however, it also serves to enhance community and natural
values with permanent pools, wetlands, island habitats, upland reforestation
areas, and the coastal prairie area. While various groups have shown an
interest in developing educational features, bridges, boardwalks, and other
public use facilities, none of these amenities are currently within
Compartment 3.
3.2
Soils
The coastal prairie is generally level with several distinctive knolls and mima
mounds. The soils within the 15-acre coastal prairie management area are
classified as Bernard-Edna Complex soils. Bernard clay loam and Edna fine
sandy loam are the major soils in the general Bernard-Edna soil Complex and
are highly associated with prairie ecosystems.
The Bernard soil makes up about 55 percent of the Soil Complex. It is located
generally in slightly concave depressions and on the flats between the knolls
and mima mounds of the Edna soil.
The Edna soil makes up about 30 percent of the Soil Complex. It is mainly on
convex knolls, ridges, and circular mima mounds. The remainder of the Soil
Complex is made up of closely associated soils, such as Addicks, Lake
Charles, and Clodine soils.
The soils in this complex are somewhat poorly drained and are generally
saturated in winter and in early spring. Internal drainage and permeability are
very slow. The available water capacity is medium to high. The moundy
surface and poor drainage are the major concerns of management in these soil
types (NRCS, 1976).
Continued on next page
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3.0 Site Description, continued
3.3
Management
Units
HCFCD established the 15-acre Coastal Prairie Management Area centered
around the remnant coastal prairie habitat and extant H. texana colonies. The
area has been divided into four management units: MU1, MU2 MU3, and
MU4 (Figure 2). Management activities within each unit are consistent with
those outlined in the Biological Assessment (HCFCD, 2007).
The primary management approach is removal of woody vegetation
encroaching on the Coastal Prairie Management Area since about 1990. As
the prairie ecosystem recovers and desirable vegetation is established, each
unit will be placed on a rotating management schedule (Table 1). Specialized
management techniques have also been developed for management of H.
texana populations.
3.4
Coastal Prairie
Several remnant areas of coastal prairie have been identified within the
Coastal Prairie Management Area. These communities are dominated by
native species such as little bluestem (Schizachyrium scoparium), Indian grass
(Sorghastrum nutans), Texas coneflower (Rudbeckia texana) and various
sedge species (Carex spp.). For a complete list of plant species found at the
site, refer to Appendix A
3.5
Wet Coastal
Prairie
Wetter areas of coastal prairie habitat were mapped separately. Species
include Gulf cordgrass (Spartina spartinae), Indian plantain (Arnoglossum
spp.) and Rattlesnakemaster (Eryngium aquaticum). For a complete list of
plant species found at the site, refer to Appendix A
3.6
Hymenoxys
texana
Two extant populations of Texas prairiedawn (H. texana) and one area with
associated species and habitat have been identified within the Coastal Prairie
Management Area. Both H. texana Site A and Site B, as well as the
associated habitat, are depicted in Figure 3. Fences were constructed around
the two extant populations, and access to the third associated area is
restricted. While the known populations of H. texana were dormant for
several years, they have been observed every Spring since April 2012.
HCFCD Coastal Prairie Management Plan
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3.0 Site Description, Continued
3.7
Forested Buffer
A forested buffer will be left along a portion of the northern perimeter of the
Coastal Prairie Management Area. This forested buffer was generally a
thicket of opportunistic trees and shrubs dominated by common hackberry
(Celtis occidentalis), ash (Fraxinus spp.), elm (Ulmus spp.), yaupon (Ilex
vomitoria), and oak (Quercus spp.) as well as invasive Chinese tallow
(Triadica sebifera), Chinese Elm (Ulmus parvifolia) and Chinese Privet
(Ligustrum sinense). In early 2015, the forested buffer was cleared of all
invasive trees.
Native tree saplings were planted in February 2015 to replace the invasive
trees and reclaim any bare space created by invasive removal. A mix of 150
individuals of the following species were planted: Swamp Red Maple (Acer
rubrum var. drummondii), Sweetgum (Liquedambar styraciflua), Eastern
Sycamore (Platanus occidentalis), Pecan (Carya illinoinensis), Loblolly Pine
(Pinus taeda), Cedar Elm (Ulmus crassifolia), American Elm (Ulmus
americana), Redbud (Cercis canadensis), Mexican Plum (Prunus mexicana),
Shumard’s Oak (Quercus shumardii), Wax Myrtle (Myrica cerifera) and Bur
Oak (Quercus macrocarpa) (Appendix E).
HCFCD Coastal Prairie Management Plan
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Version 3.0
Figure 2. Willow Waterhole Coastal Prairie Management Area
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
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4.0 Coastal Prairie Habitat Management
4.1
Introduction
Compliance with NEPA, required establishment of a 15-acre Coastal Prairie
Management Area within Compartment 3 of the WWH Detention Basin
complex according to the EA (HCFCD, 2008). This area, as well as known
areas of H. texana, has been excluded from severe ground disturbance
activities associated with flood damage reduction.
HCFCD identified and mapped the coastal prairie and wet coastal prairie
remnants within Compartment 3, and determined the extent of the Coastal
Prairie Management Area (Figure 2). This management area provides the
most suitable habitat for prairie ecosystem restoration with minimal impacts
to basin design.
Once the Coastal Prairie Management Area boundaries were delineated,
HCFCD proceeded with activities to enhance and manage the coastal prairie
habitat. These improvements are continually being achieved through:
 Tree Removal;
 Undesirable Plant Control;
 Motte Establishment;
 Native Plant Transplanting;
 Mowing; and
 Transect Monitoring.
The Coastal Prairie Management Area has been excluded from basin
operations and HCFCD standard cyclic maintenance. Four management units
have been delineated. Each management unit has a specific management
regime to introduce variable disturbance and promote suitable coastal prairie
habitat.
4.2
Tree Removal
Initial steps toward establishment of the 15-acre coastal prairie conservation
area entailed clearing of woody vegetation. In January 2010, qualifying trees
were transplanted to Compartment 2 of the WWH Detention Basin complex.
After that initial transplanting activity, the bulk of the remaining trees within
an approximate 7 acre area were cleared. This method consists of
mechanically cutting down mature trees and shredding them into mulch, on
site. This activity took place in March 2010. Large woody debris and mulch
was raked into piles under existing trees to promote grass and forb
propagation on the majority of the site.
Continued on next page
HCFCD Coastal Prairie Management Plan
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4.0 Coastal Prairie Habitat Management, continued
4.2
Tree Removal
(Continued)
An additional 7-acre area was cleared in December 2013, leaving a forested
buffer along a portion of the northern perimeter. This forested buffer will
remain since it adds to site diversity, provides a privacy screening for
adjacent landowners, and restricts potential access to the Coastal Prairie
Management Area. As described in Section 3.7, clearing of non-native
species and select trees has occurred within and adjacent to that forested
buffer.
4.3
Undesirable
Plant Control
Undesirable overstorey trees that were growing within remnants of coastal
prairie habitat were treated with herbicide to avoid potential impacts to the
desirable vegetation that could be caused during hydro-axing. Herbicide
applications were made to mature woody vegetation within the Coastal Prairie
Management Area during the fall of 2010 and 2011.
Herbicide application methods included basal bark application using a HypoHatchet® and machetes to apply Garlon 3A, and an injection method using an
EZ-Ject® lance with capsules of Copperhead. Species treated included Water
Oak (Quercus Nigra), Yaupon (Ilex vomitoria), American Elm (Ulmus
americana), Green Ash (Fraxinus pennsylvanica), and invasive Chinese
Tallow (Triadica sebifera).
Ongoing foliar treatments, applied by contractors, occur on an as needed basis
to treat vegetation such as Chinese tallow (Triadica sebifera) saplings and
yaupon (Ilex vomitoria).
Herbicide monitoring for adverse effects and success rates occur post
application at 1 month, 6 month and 12 month intervals. Herbicide
monitoring reports are retained on file for two years in compliance with Texas
Department of Agriculture (TDA) requirements.
Continued on next page
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4.0 Coastal Prairie Habitat Management, continued
4.4
Motte
Establishment
After initial tree removal efforts, an evaluation of all trees remaining on the
site was completed to establish appropriate locations for mottes (groupings of
trees within the prairie). This evaluation was based on tree condition,
location, species, number, and land use and access. Figure 2 shows the
location of mottes within the prairie management area and outside the
forested buffer. Tree removal and motte establishment was completed in
Management Units 1, 2 and 3 in early 2015. Tree removal and motte
establishment will occur in Management Unit 4 in late 2015.
4.5
Native Plant
Transplanting
Once woody vegetation was removed, the opportunity to transplant prairie
vegetation was apparent. Native prairie grasses and wildflowers from the
future site of Compartment 3 were rescued and transplanted within the prairie
conservation area. In December 2010, March 2011, April 2012, April 2013,
the District, along with local partners, rescued and transplanted prairie
vegetation at Willow Waterhole. These activities are ongoing.
4.6
Mowing
While prescribed burning is an excellent technique for suppressing
undesirables and promoting natives within prairie ecosystems, it was decided,
at this time, that this technique was not appropriate for the urban setting of
Willow Waterhole.
Mowing of each management unit on a rotation cycle, twice per year, is the
preferred method for controlling the majority of woody species. High deck
mowing (10-12 inches), coupled with spot treatments of herbicide, has been
used as a method to control the reoccurrence of woody vegetation throughout
the coastal prairie conservation area. Mowers are cleaned thoroughly before
each use on the site. The reduction of woody vegetation will provide better
opportunities for natural propagation of native prairie species.
Mowing is scheduled to occur twice annually within the coastal prairie
conservation area as recommended through the Biological Assessment
(HCFCD, 2007). One mowing event will occur prior to the onset of summer
heat (May, June, July) and the second in the fall (Nov., Dec., Jan.).
Mowing is to be done only when the site is dry enough to prevent rutting by
mower tires. Hand trimming may be used as an alternative to reduce the
potential impacts from mowing.
Continued on next page
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4.0 Coastal Prairie Habitat Management, continued
4.7
Transect
Monitoring
HCFCD is monitoring plant density and aerial coverage of remnant
vegetation and propagating vegetation within the Coastal Prairie Management
Area, using six (6) transect sites, each 60 feet long. These transects were
randomly selected with two transects located within each management unit
(Figure 3). A seventh transect will be added in Management Unit 4.
Monitoring has been conducted using the line intercept method. Monitoring
occurs twice annually; once during the spring flowering season and once in
the fall. Monitoring results provide species composition and percent cover
(Appendix B).
4.8
Long-Term
Maintenance
A mowing schedule has been developed for each management unit to vary
disturbance and promote the growth of desirable coastal prairie vegetation.
Mowing regimes have been scheduled around growing and flowering seasons
to minimize impacts to native prairie grasses and wildflowers (Table 1).
The H. texana sites will be trimmed twice per year to keep woody and other
undesirable species under control. Hand trimmers and mowers will be used in
these areas. Woody species surrounding the sites will also be cleared.
Table 1: Example Mowing Regime
YEAR 1
Date
May
June
July
November
December
January
MU1
MU2
MU3
H. texana
Mow
Mow
Trim
Mow
Mow
Mow
Trim
MU3
H. texana
Mow
YEAR 2
Date
May
June
July
November
December
January
HCFCD Coastal Prairie Management Plan
MU1
MU2
Mow
Mow
Trim
Mow
Mow
Mow
Trim
Mow
Willow Waterhole – D512-01-00
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Figure 3. Willow Waterhole Coastal Prairie Management – Monitoring Transects and H. texana
HCFCD Coastal Prairie Management Plan
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Version 3.0
5.0 Texas Prairiedawn (H. texana) Management
5.1
Introduction
Texas prairiedawn (H. texana) was federally-listed as an endangered species
on March 13, 1986 (USFWS, 1986). It is also listed as endangered by the
state of Texas. The objective of this plan is to preserve extant populations of
H. texana within the site and to promote potential expansions of these
communities in the future.
H. texana is an annual forb, growing 36-180 millimeters tall with several
divergent branches arising from a rosette of basal leaves. Leaf margins are
shortly toothed or lobed from mid-blade to tip. Disk flowers are yellow and
small appearing in early spring, as early as February and as late as May
(USFWS, 1986).
Preferred habitat for H. texana appears to be in micro-areas where a
competitive advantage exists, likely due to its ability to tolerate saline soils. A
typical H. texana location occurs on the edge of or in the flats between mima
mounds where vegetation is sparse and bare soils are common. A continuous
disturbance regime is required in order to facilitate these poor soil conditions
(USFWS, 1986).
Historically disturbed sites such as abandoned rice fields, vacant lots and
pastures, where mima mounds had been leveled, were occupied by H. texana.
Though any severe disturbances, such as plowing, that eliminate the soil
horizon could be a severe threat to the species (USFWS, 1989). The potential
for direct impacts to H. texana within Willow Waterhole has been greatly
reduced by creating alternatives to soil placement and altering detention basin
design.
Again, while prescribed burning is an excellent technique for suppressing
undesirables and promoting H. texana, it was decided that this technique was
not appropriate for the urban environments adjacent to Willow Waterhole.
5.2
Operations
H. texana was identified and located in Sites A and B during field visits in
2012 (Figure 3). Prior to that the species was not found for several years. The
15-acre Coastal Prairie Management Area has been excluded from basin
operations in compliance with NEPA requirements. Severe ground
disturbance activities such as rutting, plowing and disking have been
excluded from the H. texana sites. Fencing and buffers have been established
around each H. texana colony to exclude such disturbances.
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5.0 Texas Prairiedawn (H. texana) Management, continued
5.2
Operations
(Continued)
H. texana Site A, located within Management Unit 3 (refer to Figure 3) was
originally fenced in September 2011 with four strands of barbed-wire. After
the area around the endangered plant colony was cleared of woody vegetation
in December 2013, the fenced area was expanded and replaced with hogmesh
fencing material. A pedestrian access gate with a lock was installed to restrict
access to Site A.
H. texana Site B was isolated with a locked six-foot cyclone, barbed wire
fence in 2006 (Figure 3). The area around the fence, within Management Unit
4 was cleared of woody vegetation in December 2013. Management of open
buffers will occur annually with the removal of encroaching woody
vegetation.
The third potential site for H. texana is located at the easternmost site shown
on Figure 3 as “Associated Site”. This site exhibits potentially suitable habitat
for H. texana and contains associated species such as Iva angustifolia, Krigia
occidentalis, Spartina spartinae, Eleocharis montevidensis, Plantago
elongate, and Berchemia scandens (Brown, 2002).
Final basin design will incorporate the required 100 ft buffer at each H.
texana site in compliance with NEPA requirements.
Hand mowing is scheduled to occur twice annually within the H. texana sites,
once prior to the onset of summer heat (May) and once in November.
Mowing is to be done only when the site is dry enough to prevent rutting by
mower tires. Hand trimming may be used as an alternative to reduce the
impacts of mowing.
Mowing will be the primary method for controlling the encroachment of
woody species within H. texana buffers. Large diameter woody vegetation
may initially need to be controlled using herbicides or other mechanical
means.
5.3
Monitoring
Monitoring and reporting of plant density, areal coverage and reproductive
success for the existing H. texana colonies within the Willow Waterhole will
be submitted annually to USFWS and USACE.
Prior to April 2012, the H. texana colonies were not located for several years.
Since the plant species has been located, HCFCD has developed a detailed
monitoring plan found in Appendix D.
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Page 17
Version 3.0
6.0 Trails & Signage
6.1
Introduction
The WWH Detention Basin Complex has been designed to accommodate
public use facilities, such as: bridges, trails, park benches, pavilions,
interpretative signage and trash cans. While the City of Houston has installed
some facilities within Compartment 5, generally no partners have been
identified to fund and install public use features in the future.
6.2
Trails
HCFCD plans to work with a landscape architect to develop an access plan
for the Coastal Prairie Management Area. When complete, this Public Access
Plan will be included in Appendix C.
HCFCD will maintain access to the identified H. texana sites for maintenance
and monitoring.
6.3
NMZ Signs
No Mow Zone signs were installed along the southern border of the Coastal
Prairie Management Area in December 2010. The purpose of the signs is to
notify mowing crews of the sensitivity of the site and provide a physical
barrier for mowing crews to follow.
Signs, placed approximately every 50-feet, instruct crews in both English and
Spanish not to mow beyond that point.
6.4
Interpretive
Signs
HCFCD plans to include educational signs at the perimeter of the 15-acre
Coastal Prairie Management Area to instruct visitors that this habitat is not to
be disturbed (Figure 4).
The Public Access Plan will also include interpretive signage at specified
locations along the public use trails.
6.5 Fencing
To exclude the Coastal Prairie Management Area from ongoing basin
construction activity, and to protect it from illegal dumping and vehicular
traffic, a five strand barbed-wire fence was installed around Management
Units 1, 2, and 3 along the southern, western, and eastern boundaries. The
northern boundary abuts residential homes. No fence was installed to the
north. A pedestrian access gate was installed at the end of Windwood Dr. and
two maintenance access gates are located on the southern fenceline.
Additional fence installation will occur once preparations for Management
Unit 4 have been completed, and the Public Access Plan is finalized.
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Page 18
Version 3.0
Figure 4. Perimeter Signage
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Page 19
Version 3.0
7.0 Communications and Community Relations
7.1
Introduction
Public communication regarding the purpose and function of HCFCD’s
Willow Waterhole Detention Basin is important. WWH Detention Basin
complex is heavily used by the community. On any given day it is common to
see walkers, and birders utilizing the facility. Public schools nearby could
also benefit from outdoor educational experiences at the detention basin
complex.
The Willow Waterhole Greenspace Conservancy, Houston Audubon Society,
and many groups remain active at the site, providing volunteer assistance for
prairie grass rescue, vegetation monitoring and general site maintenance.
Other partners will be identified as public interest increases.
7.2
Public
Education
Effective property management requires attention to community relations.
Outreach and public education is an integral part of ecosystem restoration.
Unique public educational and recreational opportunities such as hiking,
biking, photography and birding are planned for the site.
These opportunities may be realized throughout the site with the addition of
hike and bike trails, boardwalks and bird viewing stations
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Page 20
8.0
Version 3.0
References
Brown, Larry E. 2002. A search for Hymenoxys texana Sites during March at HCFCD
Unit D512-01-00-R001.
Harris County Flood Control District (HCFCD). 2008. Brays Bayou Flood Control
Project, Harris County, TX; Alternative to the Diversion Separable Element; General
Reevaluation Report; Environmental Assessment.
HCFCD. 2007. Biological Assessment for Brays Bayou Federal Flood Control Project:
Alternative to the Diversion Separable Element Harris County, TX
Natural Resources Conservation Service (NRCS; formerly Soil Conservation Service
[SCS]). 1976. Soil Survey of Harris County, Texas. United States Department of
Agriculture.
U.S. Fish and Wildlife Service (USFWS). 1986. Determination of Endangered Species
Status for Hymenoxys texana, Federal Register 51:8681-8683. Washington D.C.
USFWS. 1989. Hymenoxys texana Recovery Plan. S.M. Young and L.E. Brown, editors.
Regional Office, Albuquerque, New Mexico.
U.S. Geological Survey. 2000. Coastal Prairie. http://www.nwrc.usgs.gov/factshts/01900.pdf
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
APPENDIX A
COASTAL PRAIRIE MANAGEMENT AREA PLANT INVENTORY
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Family – Scientific
Family – Common
Scientific Name
ACANTHACEAE
ACANTHACEAE
ACANTHACEAE
ALISMATACEAE
ACANTHUS
ACANTHUS
ACANTHUS
WATER PLANTAIN
ALLIACEAE
ONION
ALLIACEAE
ALLIACEAE
ALTINGIACEAE
ONION
ONION
SWEET GUM
AMARANTHACEAE
AMARYLLIDACEAE
ANACARDIACEAE
APIACEAE
APIACEAE
APIACEAE
APOCYNACEAE
APOCYNACEAE
APOCYNACEAE
APOCYNACEAE
AQUIFOLIACEAE
AQUIFOLIACEAE
ARECACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
AMARANTH
AMARYLLIS
SUMAC FAMILY
CARROT FAMILY
CARROT FAMILY
CARROT FAMILY
MILKWEED
MILKWEED
MILKWEED
MILKWEED
HOLLY FAMILY
HOLLY FAMILY
PALM FAMILY
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
Justica lanceolata
Ruellia humilis
Ruellia nudiflora
Sagittaria papillosa
Allium canadense var.
canadense
Allium canadense var.
mobilense
Nothoscordum bivalve
Liquidambar styraciflua
Gossypianthus lanuginosum
tenuifolium
Zephyranthes traubii
Toxicodendron radicans
Limnosciadium pumilum
Polytaenia nuttallii
Torilis arvensis
Asclepias linearis
Asclepias verticillata
Asclepias viridis
Nerium oleander
Ilex decidua
Ilex vomitoria
Sabal minor
Ambrosia psilostachya
Arnoglossum ovatum
Baccharis halimifolia
Boltonia diffusa
Calyptocarpus vialis
Cirsium horridulum
Conoclinium coelestinum
Conyza canadensis
Coreopsis lanceolata
Coreopsis tinctoria
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
Erigeron tenuis
Eupatorium compositifolium
Eupatorium hyssopifolium
Eupatorium lancifolium
Eupatorium serotinum
Euthamia gymnspermoides
HCFCD Coastal Prairie Management Plan
Common Name
Loose-flowered waterwillow
Fringeleaf wild petuna
Violet wild petuna
Papillose arrowhead
Meadow garlic
Meadow garlic
False garlic
Sweet gum
Cotton flower
Traubs Rain-Lily
Poison Ivy
Dog sunshade
Prairie parsley
Hedge parsley
Narrowleaf milkweed
Whorled milkweed
Green milkweed
Oleander
Deciduous Holly
Youpon
Dwarf palmetto
Western Ragweed
Ovateleaf Indian Plantain
Sea-myrtle
Smallhead doll's daisy
Straggler daisy
Horrid thistle
Mist flower
Horseweed
Lanceleaf tickseed
Golden tickseed
Slenderleaf Daisy
Fleabane
Yankeeweed
Narrowleaf thoroughwort
Lanceleaf thoroghwort
Fall thoroughwort
Texas goldentop
Willow Waterhole – D512-01-00
Family - Scientific
ASTERACEAE
Family- Common
SUNFLOWER
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
ASTERACEAE
BERBERIDACEAE
BORAGINACEAE
BRASSICACEAE
CAMPANULACEAE
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
SUNFLOWER
BARBERRY FAMILY
BORAGE FAMILY
MUSTARD FAMILY
LOBELIA FAMILY
HCFCD Coastal Prairie Management Plan
Scientific Name
Euthamia leptocephala
Gaillardia aestivalis var.
aestivalis
Gamochaeta antillana
Gamochaeta pennsylvanica
Helenium amarum
Helenium flexuosum
Helianthus angustifolus
Helianthus annuus
Helianthus maximiliani
Hymenoxys texana
Iva angustifolia
Iva annua
Krigia occidentalis
Liatris acidota
Liatris bractata
Liatris pycnostachya
Packera tampicanus
Palafoxia rosea
Pluchea odorata
Pyrrhopappus carolinianus
Pyrrhopappus pauciflorua
Ratibida columnifera
Rayjacksonia aurea
Rudbeckia hirta
Rudbeckia texana
Silphium radula var. gracile
Solidago altlissima
Solidago sempervirens
Sonchus asper
Symphyotrichum divaricatum
Symphyotrichum dumosum
Symphyotrichum ericoides
Symphyotrichum lanceolatum
Symphyotrichum lateriflorum
Taraxacum officinale
Veronica missurica
Youngia japonica
Nandina domestica
Lithospermum incisum
Lepidium virginicus
Lobelia puberula
Common Name
Flat-topped goldentop
Lanceleaf Indian-blanket
Narrowleaf cudweed
Pennsylvanica everlasting
Bitterweed
Purplehead sneezeweed
Swamp sunflower
Common sunflower
Maximilian sunflower
Prairie dawn
Narrowleaf sumpweed
Sumpweed
Dwarf dandelion
Sharp gay-feather
Coastal gay-feather
Tall gay-feather
Great plains ragwort
Rosy palafox
Sweetsent
Carolina false dandelion
Cutleaf false dandelion
Prairie coneflower
Houston camphor daisy
Blackeyed susan
Texas coneflower
Rosin-weed
Common goldenrod
Seashore goldenrod
Spiny sowthistle
Blueweed aster
Rice-button aster
Prairie aster
Large flower aster
Farewell-summer aster
Dandelion
Missouri ironweed
Japanese hawkweed
Heavenly bamboo
Narrowleaf puccon
Pepperwort
Blue cardinal flower
Willow Waterhole – D512-01-00
Family - Scientific
CAMPANULACEAE
CANNABACEAE
CAPRIFOLIACEAE
CAPRIFOLIACEAE
COMMELINACEAE
COMMELINACEAE
CONVOLVULACEAE
CONVOLVULACEAE
CONVOLVULACEAE
CRASSULACEAE
CUCURBITACEAE
CUCURBITACEAE
CUPRESSACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
Family- Common
LOBELIA FAMILY
HOP FAMILY
HONEYSUCKLE
HONEYSUCKLE
SPIDERWORT
SPIDERWORT
MORNING GLORY
MORNING GLORY
MORNING GLORY
STONECROP
GOURD FAMILY
SQUASH FAMILY
CEDAR FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
Scientific Name
Triodanis biflora
Celtis laevigata
Lonicera japonica
Valerianella radiata
Commelina erecta
Tradescantia ohiensis
Dichondra carolinensis
Evolvulus sericeus
Ipomoea cordatotriloba
Crassula aquatica
Cucumis melo var. texana
Melothria pendula
Juniperus virginiana
Carex brevior
Carex bushii
Carex cherokeensis
Carex flaccosperma
Carex meadii
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
CYPERACEAE
CYPERACEAE
SEDGE FAMILY
SEDGE FAMILY
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
CYPERACEAE
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
SEDGE FAMILY
Carex microdonta
Carex tetrastachya
Carex triangularis
Carex vulpinoidea
Cyperus acuminatus
Cyperus articulatus
Cyperus croceus
Cyperus echinatus
Cyperus entrerianus
Cyperus haspan
Cyperus ochraceus
Cyperus pseudovegetus
Cyperus reflexus
Cyperus retrorsus var.
retrorsus
Eleocharis montevidensis
Fimbristylis puberula var.
puberula
Rhynchospora caduca
Rhynchospora corniculata
Rhynchospora globularis
Rhynchospora harveyi
Scleria ciliata var. ciliata
HCFCD Coastal Prairie Management Plan
Common Name
Venus looking-glass
Sugar Hackberry
Japanese honeysuckle
Beaked Cornsalad
Whitemouth dayflower
Spiderwort
Carolina ponyfoot
Silver dwrf-morning-glory
Tievine
Water pigmy-weed
Cantaloupe
Melonette
Eastern red cedar
Short-beak bladder-sedge
Bush's bladder -sedge
Cherokee bladder-sedge
Thin-fruit bladder-sedge
Mead's sedge
Little-tooth Bladdersedge
Britton's sedge
Eastern bladder-sedge
fox sedge
Taper-leaf flat-sedge
Jointed flat-sedge
Baldwin's flat-sedge
Globe flat sedge
Deep rooted Flat sedge
Soft flat sedge
Flat sedge
Marsh flat-sedge
Red-bracted flat-sedge
Ovoid flat-sedge
Spike rush
Fimbry
anglestem beaksedge
Short-bristle beak-sedge
Globe beak-sedge
Horn rush
Fringed nut-rush
Willow Waterhole – D512-01-00
Family - Scientific
CYPERACEAE
EBENACEAE
EUPHORBIACEAE
EUPHORBIACEAE
EUPHORBIACEAE
EUPHORBIACEAE
EUPHORBIACEAE
FABACEAE
FABACEAE
FABACEAE
Family- Common
SEDGE FAMILY
EBONY FAMILY
SPURGE FAMILY
SPURGE FAMILY
SPURGE FAMILY
SPURGE FAMILY
SPURGE FAMILY
BEAN FAMILY
BEAN FAMILY
BEAN FAMILY
FABACEAE
FABACEAE
BEAN FAMILY
BEAN FAMILY
FABACEAE
FABACEAE
FABACEAE
FABACEAE
FABACEAE
FABACEAE
FABACEAE
FABACEAE
FABACEAE
FABACEAE
FABACEAE
FABACEAE
FAGACEAE
FAGACEAE
FAGACEAE
FAGACEAE
BEAN FAMILY
BEAN FAMILY
BEAN FAMILY
BEAN FAMILY
BEAN FAMILY
BEAN FAMILY
BEAN FAMILY
BEAN FAMILY
BEAN FAMILY
BEAN FAMILY
BEAN FAMILY
BEAN FAMILY
OAK FAMILY
OAK FAMILY
OAK FAMILY
OAK FAMILY
Scientific Name
Scleria pauciflora
Diospyros virginiana
Acalypha gracilens
Croton capitatus
Croton monanthogynus
Euphorbia spathula
Triadica sebiferum
Acacia farnesiana
Albizia julibrissin
Baptisia sphaerocarpa
Cercis canadensis var.
canadensis
Chamaecrista fasciculata
Dalea compacta var.
compacat
Desmanthus illinoensis
Desmodium sessilifolium
Indigofera miniata
Lathyrus pusillus
Mimosa hystricina
Mimosa strigillosa
Neptunia lutea
Neptunia pubescens
Parkinsonia aculeata
Sesbania drummondii
Vicia ludoviciana
Quercus hemisphaerica
Quercus nigra
Quercus phellos
Quercus virginiana
GENTIANACEAE
HALOGRACEAE
HALOGRACEAE
HYDROLEACEAE
HYPERICACEAE
HYPERICACEAE
HYPOXIDACEAE
IRIDACEAE
GENTIAN FAMILY
WATER MILLFOIL
WATER MILLFOIL
FALSE FIDDLEHEAD
SAINT-JOHN'S-WORT
SAINT-JOHN'S-WORT
STAR-GRASS FAMILY
IRIS FAMILY
Sabatia campestris
Myriophyllum pinnatum
Proserpinaca palustris
Hydrolea ovata
Hypericum drummondii
Hypericum hypericoides
Hypoxis hirsuta
Herbertia lahue
HCFCD Coastal Prairie Management Plan
Common Name
Few-flower nut-rush
Persimmon
Three-seed-mercury
Wooly croton
Prairie tea
Warty spurge
Chinese tallow
Huisache
Silk tree
Yellow false indigo
Red bud
Partridge pea
Purple prairie clover
Illinoia bundle flower
Sessleaf ticktrefoil
Scarlet pea
Tiny pea
Sensitive briar
Powder puff
Yellow-puff
Tropical puff
Ratama
Rattlebush
Louisiana vetch
Upland laurel oak
Water Oak
Willow oak
Live oak
Meadow beauty/Texas
star
Watermillfoil
Marsh mermaidweed
Ovate false fiddlehead
Nits-and-lice
St.Andrew's cross
Yellow star grass
Herbertia
Willow Waterhole – D512-01-00
Family - Scientific
IRIDACEAE
IRIDACEAE
IRIDACEAE
JUNCACEAE
JUNCACEAE
JUNCACEAE
JUNCACEAE
JUNCACEAE
KRAMERIACEAE
LAMIACEAE
LAMIACEAE
LAMIACEAE
LAMIACEAE
LAMIACEAE
LAMIACEAE
LAMIACEAE
LAMIACEAE
LAMIACEAE
Family- Common
IRIS FAMILY
IRIS FAMILY
IRIS FAMILY
RUSH FAMILY
RUSH FAMILY
RUSH FAMILY
RUSH FAMILY
RUSH FAMILY
RATANY FAMILY
MINT FAMILY
MINT FAMILY
MINT FAMILY
MINT FAMILY
MINT FAMILY
MINT FAMILY
MINT FAMILY
MINT FAMILY
MINT FAMILY
LINACEAE
LINACEAE
FLAX FAMILY
FLAX FAMILY
LYTHRACEAE
MAGNOLIACEAE
LOOSESTRIFE
MAGNOLIACEAE
MALVACEAE
MALLOW FAMILY
MALVACEAE
MALVACEAE
MALVACEAE
MORACEAE
MYRICACEAE
OLEACEAE
OLEACEAE
OLEACEAE
OLEACEAE
ONAGRACEAE
ONAGRACEAE
MALLOW FAMILY
MALLOW FAMILY
MALLOW FAMILY
MULBERRY FAMILY
BAYBERRY FAMILY
OLIVE FAMILY
OLIVE FAMILY
OLIVE FAMILY
OLIVE FAMILY
EVENING PRIMROSE
EVENING PRIMROSE
Scientific Name
Sisyrinchium angustifolium
Sisyrinchium langloisii
Sisyrinchium rosulatum
Juncus acuminatus
Juncus brachycarpus
Juncus dichotomus
Juncus marginatus
Juncus validus
Kramera lanceolatus
Callicarpa americana
Hedeoma hispida
Hyptis alata
Monarda citriodora
Salvia azurea
Salvia lyrata
Scutellaria parvula
Stachys crenata
Stachys drummondii
Linum berlandieri var.
berlandieri
Linum medium var. texanum
Lythrum alatum var.
lanceolatum
Magnolia grandiflora
Callirhoe involucrata var.
lineariloba
Malvastrum
coromandelianum
Malvaviscus arboreus
Sida spinosa
Morus alba
Morella cerifera
Fraxinus berlandieriana
Fraxinus pennsylvanica
Ligustrum lucidum
Ligustrum sinense
Gaura lindheimeri
Gaura longiflora
ONAGRACEAE
EVENING PRIMROSE
Ludwigia glandulosa
HCFCD Coastal Prairie Management Plan
Common Name
Blue-eyed grass
Blue-eyed grass
Blue-eyed grass
Tapertip rush
Short-fruit rush
Fork rush
Field rush
Flatleaf rush
Ratany
American beauty berry
Rough false pennyroyal
Clustered bushmint
Lemon beebalm
Azure blue sage
Lyreleaf sage
Small skullcap
Mouseear betony
Pink mint
Flax
Stiff yellow flax
Winged loosestrife
Southern magnolia
Winecup
Threelobe false mallow
Wax-mallow
Prickley fanpetals
White Mulberry
Wax myrtle
Mexican ash
Green ash
Glossy privet
Chinese privet
Lindheimer's beeblossom
Longflower beeblossom
Glandular Primrosewillow
Willow Waterhole – D512-01-00
Family - Scientific
Family- Common
Scientific Name
ONAGRACEAE
EVENING PRIMROSE
Ludwigia linearis
ONAGRACEAE
ONAGRACEAE
ORCHIDACEAE
OROBANCHACEAE
OROBANCHACEAE
EVENING PRIMROSE
EVENING PRIMROSE
ORCHID FAMILY
BROOMRAPE
BROOMRAPE
Oenothera linifolia
Oenothera speciosa
Spiranthes vernalis
Agalinis heterophylla
Castilieja indivisa
OXALIDACEAE
OXALIDACEAE
OXALIDACEAE
OXALIDACEAE
PASSIFLORACEAE
PINACEAE
PLANTAGINACEAE
PLANTAGINACEAE
PLANTAGINACEAE
PLANTAGINACEAE
PLANTAGINACEAE
PLANTAGINACEAE
PLANTAGINACEAE
POACEAE
POACEAE
POACEAE
POACEAE
WOOD SORREL
WOOD SORREL
WOOD SORREL
WOOD SORREL
PASSIONFLOWER
PINE FAMILY
SNAPDRAGON
SNAPDRAGON
SNAPDRAGON
SNAPDRAGON
SNAPDRAGON
SNAPDRAGON
SNAPDRAGON
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
POACEAE
GRASS FAMILY
POACEAE
POACEAE
GRASS FAMILY
GRASS FAMILY
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
Oxalis debilis
Oxalis dillenii
Oxalis texana
Oxalis violacea
Passiflora incarnata
Pinus elliotii
Nuttallanthus texanus
Plantago aristata
Plantago elongata
Plantago heterophylla
Plantago lanceolata
Plantago virginica
Veronica agrestis
Agrostis elliottiana
Agrostis hyemalis
Andropogon gerardii
Andropogon glomeratus
Aristida longispica var.
geniculata
Aristida longispica var.
longispicata
Aristida oligantha
Aristida purpurascens var
purpurascens
Bothriochloa longipaniculata
Bothriochloa ischaemum
Bouteloua curtipendula
Bouteloua rigidiseta
HCFCD Coastal Prairie Management Plan
Common Name
Narrowleaf Primrosewillow
Threadleaf evening
primrose
Mexican primrose
Spring ladies's tresses
Common false foxglobe
Indian paintbrush
Bulbous nonyellow
sourgrass
Slender yellow sourgrass
Tufted yellow sourgrass
Violet sourgrass
Purple passion flower
Slash pine
Texas toadflax
Long bract plantain
Prairie plantain
Slender plantain
Plantain
Plantain
Wayside speedwell
Elliot's bentgrass
Winter bentgrass
Big bluestem
Bushy bluestem
Slimspike threeawn grass
Slimspike threeawn grass
Oldfield three-awn
Arrowfeather threeawn
Longspike silver bluestem
King ranch bluestem
Side-oats grama
Texas grama
Willow Waterhole – D512-01-00
Family - Scientific
POACEAE
POACEAE
POACEAE
POACEAE
Family- Common
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
POACEAE
GRASS FAMILY
POACEAE
GRASS FAMILY
POACEAE
POACEAE
POACEAE
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
POACEAE
POACEAE
GRASS FAMILY
GRASS FAMILY
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
HCFCD Coastal Prairie Management Plan
Scientific Name
Briza minor
Bromus catharticus
Chloris canterae
Cyndon dactylon
Dichanthelium aciculare
angustifolium
Dichanthelium acuminatum
acuminatum
Dichanthelium acuminatum
lindheimeri
Dichanthelium commutatum
Dichanthelium oligosanthes
Dichanthelium ovale var.
villosissimum
Dichanthelium scoparium
Dichanthelium
sphaerocarpon
Dichanthium annulatum
Dichanthium aristatum
Digitaria ciliaris
Digitaria cognata
Echinochloa colonum
Elymus virginicus
Eragrostis elliottii
Eragrostis secundiflora
Eragrostis spectabilis
Hordeum pusillum
Leersia hexandra
Lolium perenne
Muhlenbergii capillaris
Nassella leucotricha
Panicum dichotomiflorum
Panicum repens
Panicum rigidulum
Panicum virgatum
Paspalum denticulatum
Paspalum dilatatum
Paspalum floridanum
Paspalum langei
Paspalum plicatulum
Common Name
Quackinggrass
Rescue grass
Paraguayan windmillgrass
Bermudagrass
Needleleaf rosettegrass
Tapered rosett grass
Tapered rosette grass
Variable rosettegrass
Fewflowered rosettegrass
Egg leaf rosette grass
Velvet rosettegrass
Roundfruit rosettegrass
Kleberg bluestem
Angelton bluestem
Southern crabgrass
Carolina crabgrass
Jungle-rice grass
Virginia wildrye
Elliot's lovegrass
Red lovegrass
Purple lovegrass
Little barley
Southern ricegrass
Perennial ryegrass
Gulf muhly
Texas speargrass
Fall panicgrass
Torpedo grass
Redtop panicgrass
Switchgrass
Longtom
Dallisgrass
Florida paspalum
Rustyseed paspalum
Brownseed paspalum
Willow Waterhole – D512-01-00
Family - Scientific
POACEAE
POACEAE
POACEAE
Family- Common
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
POACEAE
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
GRASS FAMILY
POACEAE
POLYGALACEAE
POLYGONACEAE
POLYGONACEAE
POLYGONACEAE
PRIMULACEAE
PRIMULACEAE
RANUNCULACEAE
RANUNCULACEAE
RANUNCULACEAE
RANUNCULACEAE
RANUNCULACEAE
RHAMNACEAE
ROSACEAE
ROSACEAE
ROSACEAE
ROSACEAE
RUBIACEAE
RUBIACEAE
RUBIACEAE
GRASS FAMILY
MILKWORT
KNOTWEED
KNOTWEED
KNOTWEED
PRIMROSE
PRIMROSE
BUTTERCUP
BUTTERCUP
BUTTERCUP
BUTTERCUP
BUTTERCUP
BUCKTHORN
ROSE FAMILY
ROSE FAMILY
ROSE FAMILY
ROSE FAMILY
MADDER FAMILY
MADDER FAMILY
MADDER FAMILY
HCFCD Coastal Prairie Management Plan
Scientific Name
Paspalum pubiflorum
Paspalum setaceum
Paspalum urvillei
Schizachyrium scoparium var.
divergens
Setaria parviflora
Setaria pumila subsp. pumila
Sorghastum nutans
Sorghum bicolor
Sorghum halepense
Spartina spartinae
Sphenopholis obtusata
Sporobolus compositus var.
compositua
Sporobolus indicus
Sporobolus pyramidatus
Steinchisma hians
Stenotaphrum secundatum
Tridens strictus
Willcommia texana var.
texana
Polygala incarnata
Persicaria hydropiperoides
Rumex chrysocarpus
Rumex crispus
Anagallis arvensis
Anagallis minima
Anemone berlandieri
Anemone caroliniana
Ranunculus muricatus
Ranunculus platensis
Ranunculus sardosus
Berchemia scandens
Pyracantha koidzumii
Rosa bracteaea
Rubus argutus
Rubus trivialis
Diodia teres
Diodia virginiana
Galium aparine
Common Name
Harryseed paspaluim
Thin paspalum
Vaseygrass
Little bluestem
Knotroot bristlegrass
Yellow bristlegrass
Indiangrass
Milo (cultivated sorghum)
Johnsongrass
Gulf cordgrass
Prairie wedgescale
Tall dropseed
Smutgrass
Whorled dropseed
Gaping panicgrass
St, Augustine grass
Longspike tridens
Texas willkommia
Procession flower
Swamp smartweed
Amamastla
Curly dock
Scarlet pimpernel
Little pimperenel
Berandieri's anemone
Carolina anemone
Spinyfruit buttercup
Prairie buttercup
Hairy buttercup
Rattan vine
Firethorn
Macartney rose
Sawtooth blackberry
Dewberry
Poorjoe
Virginia buttonweed
Bedstraw
Willow Waterhole – D512-01-00
Family - Scientific
RUBIACEAE
RUBIACEAE
RUBIACEAE
RUBIACEAE
RUBIACEAE
SALICACEAE
SAPOTACEAE
SMILACACEAE
SOLANACEAE
SOLANACEAE
SOLANACEAE
ULMACEAE
ULMACEAE
ULMACEAE
VERBENACEAE
VERBENACEAE
VERBENACEAE
VERBENACEAE
VERBENACEAE
VERBENACEAE
VITACEAE
Family- Common
MADDER FAMILY
MADDER FAMILY
MADDER FAMILY
MADDER FAMILY
MADDER FAMILY
WILLOW FAMILY
SAPODILLA FAMILY
GREENBRIER
NIGHTSHADE
NIGHTSHADE
NIGHTSHADE
ELM FAMILY
ELM FAMILY
ELM FAMILY
VERBENA FAMILY
VERBENA FAMILY
VERBENA FAMILY
VERBENA FAMILY
VERBENA FAMILY
VERBENA FAMILY
GRAPE FAMILY
HCFCD Coastal Prairie Management Plan
Scientific Name
Galium tinctorium
Houstonia pusilla
Houstonia rosea
Sherardia arvensis
Stenaria nigricans
Populus deltoides
Sideroxylon lanuginosum
Smilax bona-nox
Physalis angulata
Physalis cinerascens
Solanum ptycanthum
Ulmus alata
Ulmus americana
Ulmus parvifolia
Lantana camara
Phyla nodiflora
Verbena brasilensis
Verbena halei
Verbena rigida
Verbena xutha
Ampelopsis arborea
Common Name
Stiff marsh bedstraw
Tiny bluet
Rose bluet
Blue fieldmatter
Diamonflower
Cottonwood
Gum bumelia
Fiddle-leaf greenbrier
Cut-leaf ground-cherry
Beech ground-cherry
Black nightshade
Winged elm
American elm
Chinese elm
West indies lantana
Frog fruit
Brazilian vervain
Texas vervain
Tuber vervain
Gulf vervain
Pepper vine
Willow Waterhole – D512-01-00
APPENDIX B
TRANSECT MONITORING DATA
Transect monitoring is ongoing, with data collected biannually. These data are extensive and
available upon request. Ecological values calculated from the data are explained and presented
below.
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Species
Richness
Species richness is simply the number of species observed with a collected
sample.
Diversity Index
Species diversity is an indicator of ecosystem health. The greater the
diversity, the greater amount of species present in the ecosystem. Healthy
ecosystems should be able to provide multiple layers and functional habitats
to support a range of species and niches. Calculating the diversity index is a
method of providing the trajectory of ecological quality within the Coastal
Prairie Management Area.
There are multiple methods to calculate species diversity within a natural
community, and the Shannon-Wiener Diversity Index has been used to assess
the data collected biannually from transects within the Coastal Prairie
Management Area. The index relies on an ecological equation based upon the
occurrence of a particular species within a sample, in this case, each
individual transect. The diversity index is a relative number which can
increase as diversity increases, or decrease as diversity decreases.
Evenness
Species evenness is a distribution assessment of all species observed within a
collected sample. It is measured by using an ecological equation to provide a
number between 0 and 1. A value of 0 means that only one specific species
dominates the entire sample and no other species is present. Values of 1
means that the total number of each species found within the sample are
observed to be evenly distributed between species.
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
All
Transects
Fall
2010
Spring
2011
Fall
2011
Spring
2012
Fall
2012
Spring
2013
Fall
2013
Spring
2014
Fall
2014
91
98
82
88
99
76
81
104
95
4.02
4.04
3.94
4.04
4.05
3.81
3.83
4.09
3.97
0.89
0.88
0.89
0.90
0.88
0.88
0.87
0.88
0.87
32
35
39
37
33
31
30
39
35
3.02
3.14
3.19
3.22
3.04
2.90
2.97
3.24
3.18
0.87
0.88
0.87
0.89
0.87
0.84
0.87
0.88
0.89
19
16
15
16
26
15
22
22
Unsafe
2.27
2.29
2.35
2.30
2.76
2.44
2.54
2.63
Unsafe
0.77
0.83
0.87
0.83
0.85
0.90
0.82
0.85
Unsafe
32
31
27
28
30
27
31
36
29
3.15
3.13
3.03
3.02
3.00
3.04
3.12
3.27
3
0.91
0.91
0.92
0.91
0.88
0.92
0.91
0.91
0.89
15
23
29
34
37
25
23
29
28
2.34
2.75
3.02
3.15
3.25
2.64
2.86
2.98
2.8
0.86
0.88
0.90
0.89
0.90
0.82
0.91
0.88
0.84
42
37
18
22
28
22
32
32
21
3.46
3.29
2.51
2.78
2.98
2.73
2.98
2.98
2.55
0.92
0.91
0.87
0.90
0.89
0.88
0.86
0.86
0.87
18
15
18
17
22
15
15
18
22
2.44
2.31
2.51
2.50
2.72
2.30
2.31
2.48
2.7
0.84
0.85
0.87
0.88
0.88
0.85
0.85
0.86
0.87
Richness
Diversity
Index
Evenness
-
-
-
-
-
-
12
12
21
-
-
-
-
-
-
2.11
2.07
2.79
-
-
-
-
-
-
0.85
0.83
0.92
Richness
Diversity
Index
Evenness
-
-
-
-
-
-
-
37
27
-
-
-
-
-
-
-
3.31
2.94
-
-
-
-
-
-
-
0.92
0.89
Richness
Diversity
Index
Evenness
Transect 1
Transect 2
Transect 3
Transect 4
Transect 5
Transect 6
Transect 7
Transect 8
Richness
Diversity
Index
Evenness
Richness
Diversity
Index
Evenness
Richness
Diversity
Index
Evenness
Richness
Diversity
Index
Evenness
Richness
Diversity
Index
Evenness
Richness
Diversity
Index
Evenness
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
APPENDIX C
WILLOW WATERHOLE – COMPARTMENT 3 DETENTION BASIN PLAN
COASTAL PRAIRIE ACCESS PLAN
The Prairie Access Plan has been developed and is available to view by visiting the following
link:
http://www.projectbrays.org/docs/reports/WillowWaterholePrairieManagementPAP.pdf.
The design of the Public Access Plan adheres to the guidelines set forth in this management plan
and in accordance with the Environmental Assessment and the Harris County Flood Control
District Policy Criteria and Procedures Manual.
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Version 3.0
APPENDIX D
HYMENOXYS TEXANA MONITORING PLAN
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
APPENDIX D - HYMENOXYS TEXANA MONITORING PLAN
Introduction
A successful monitoring regime must incorporate species-specific and sitespecific solutions as data is gathered from year-to-year. Monitoring should
not be seen as a permanent and unchanging routine, but as a process where
practices and methods can be subsequently changed according to the needs of
conservation.
H. texana, a rare, annual species, is present in its vegetative form between the
months of January and May. The ideal time of year to monitor H. texana is
late March to early April; the species flowers during this time and thus is
more conspicuous and easier to identify. Given H. texana is an annual,
unfavorable conditions can cause yearly fluctuations in population size and
may spend long periods in seed banks when faced with adverse weather, such
as low rainfall. Therefore permanent plots will not be used to monitor H.
texana. Instead, direct counting of H. texana individuals per inhabited patch
should be used to assess fluctuations in population sizes over time. Potential
habitat should be examined to record the number and area of ecologically
suitable patches, also distinguishing between inhabited and empty patches.
Changes in the surrounding environment should be recorded to monitor the
quality of patches within H. texana habitat. This involves detailed knowledge
of H. texana habitat requirements. Examples include measurement of ground
coverage, amount of plant debris, and soil conditions. These evaluations may
help explain future population changes and aid in the location of additional
suitable habitat, thereby assisting with the conservation of the species. Special
attention should be paid to any habitat changes caused by human activity.
Monitoring
Outline

A survey at Compartment 3 has been conducted to identify any
additional suitable or potential habitat, but only the sites identified in
Figure 3 have been deemed suitable at the present time.

Sites A and B have been developed for long-term monitoring.
□ A full individual count of H. texana will be performed in each
subplot at Site A and Site B annually during the flowering
period, while the Associated Site will be surveyed to confirm the
presence of H. texana.
□ During the count, the number of flowering/fruiting individuals is
recorded as well as incidence of disease or herbivory.
□ The amount of ground cover will be determined using the
Daubenmire Method.
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
APPENDIX D - HYMENOXYS TEXANA MONITORING PLAN
□ A permanent photoplot has been established.
Monitoring
Outline
(continued)
□ A full species inventory within each site has been performed.

A soil assessment has been performed to quantify the soil preferences
of H. texana.
o High amounts of electrical conductivity were observed,
resulting from high amounts of salts present in the soil.
o This is consistent with H. texana habitat and may help locate
future H. texana suitable habitat.

Monitoring
Reports
The monitoring plan will be adapted over time as meaningful data and
results are generated and site conditions fluctuate.
Monitoring reports are created annually to track the population numbers and
site conditions of the two H. texana colonies within the Coastal Prairie
Management Area. The monitoring reports are created as a standalone
document and are available upon request.
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Version 3.0
APPENDIX E
SITE PHOTGRAPHS
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Photo 1: Coastal Prairie Room Prior to Tree Clearing (3-4-2010)
Photo 2: Wet Coastal Prairie Prior to Tree Clearing (3-4-2010)
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Photo 3: Site Conditions Just After Hydro-axing, and prior to Phase I Tree Evaluation for
Motte Establishment (5-18-2010). Note further tree removal was done post Hydro-axing,
based on evaluation of tree species and condition.
Photo 4: Coastal Prairie Area with Forested Buffer and Mottes, Phase I (10-24-2011)
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Photo 5: Coastal Prairie Area with Woody Buffers (3-26-2012)
Photo 6: H. texana Site A (11-2-2011)
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Photo 7: H. texana Site B (3-22-2012)
Photo 8: H. texana within Site B (3-22-2012)
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Photo 9: H. texana Associated Site (9-30-2011)
Photo 10: Herbicide Monitoring (3-17-2011)
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00
Photo 11: Typical Transect Monitoring (3-24-2011)
Photo 12: Sapling planting within the forested buffer (2-27-2015)
HCFCD Coastal Prairie Management Plan
Willow Waterhole – D512-01-00