1. Low Impact Development Structures for Educational Opportunities
2017 EPA Region 6 Stormwater Conference
San Antonio, TX
Lauren Willis
Guadalupe-Blanco River Authority
Good afternoon, my name is Lauren Willis and I’m with the Guadalupe-Blanco River Authority and I work in the Water Quality Department. I’m going to speak about the Low Impact Development structures we’ve constructed and how to use these as educational opportunities
How many of you have been involved in Low Impact Development projects?

2. 319 Nonpoint Source Grant with TCEQ
Geronimo and Alligator Creeks Watershed Protection Plan (WPP)
Implementation - Education and Outreach
Goals
Address the bacteria impairment and nutrient concerns in Geronimo Creek
Enhance public understanding of the health of a riparian ecosystem
Tasks
Riparian Education
Nonpoint Source Pollution Education
Demonstration of Low Impact Development Practices
Total Project Costs
$306,667
Partners
Texas AgriLife Extension Service
Irma Lewis Seguin Outdoor Learning Center
We received a 319 NPS grant from the TCEQ to focus on the Geronimo & Alligator Creek WPP Implementation focusing on education & outreach.
The two main goals are to:
The three main tasks include: I’ll be focusing today on the Demonstration of Low Impact Develop Practices.
The total cost of the grant is a little over $300,000 including federal and non-federal money. The LID construction projects cost about $112,000 for the 6 structures we’ve been working on.
GBRA and project partners oversaw the development and design of 6 Low Impact Development Structures.
Workshops are be offered (the grant requires 3 ) by Texas AgriLife and are open to municipal officials, municipal staff, developers, landowners, adult education for Master Naturalists and Master Gardeners, etc.

4. Irma Lewis Seguin Outdoor Learning Center
This is a map showing where the Irma Lewis Seguin Outdoor Learning Center is located.
The mission of this organization is to:
Here you can see where the Geronimo Creek is located on the property following the blue line. The total facility has 115 acres of land to provide an outdoor classroom for all school ages. Seguin, New Braunfels and Comal ISD all visit annually.
The LID structures were installed on the property
The 1st structure to be installed was the Rain Water Harvesting System. Here you can see this is connected to a barn which is used for social gatherings
Mission
To provide an educational experience for all ages in a natural setting.
The Geronimo Creek flows through the ILSOLC facility (115 acres) and is used as part of an outdoor “classroom” for learning about nature and the environment. School children of all ages from the Seguin, New Braunfels and Comal ISDs visit the facility annually.

5. Rainwater Harvesting
This 5,000 gallon rainwater Harvesting tank was our first project to be installed along with the signage that’s 4ft x 3ft size
The goal of all the signage is to be self explanatory for all individuals visiting the property.
All signs list the ‘Benefits’ and ‘How it Works’

6. Rainwater Harvesting 5,000 Gallon Tank Construction Cost: $11,000
$7,000 Tank, sand pad and rock aggregate
$300 brick ring and gravel around tank
$1, linear feet of gutters
$700 general construction supplies & gutter downspout to tank
$900 Pump, pump wiring and weather-proof structure
$275 irrigation supplies to garden
Signage Cost: $450
$280 build frame
$156 printing signage
Construction Time: 1 Week
Construction Time includes: 1 day to install gutters, 2 days for the tank, 1 day to build signage and trench line for irrigation
Installation of pump was done by on sight personnel (counted towards volunteer hours)
Something that is unique for this structure is that it had Turn Key installation and very easy to get bids on

7. I want to put this map up to show you where all our structures are located. The second structure to be installed is the Rain Garden.

8. Rain Garden Before After
The excavated area is 45 feet long, 20 feet wide and 5 feet deep
1 foot of #57 stone
The underdrain system was necessary because of the clay soils – 4in perforated pipe with 1% slope towards the riser pipe
Add 2 inches of washed #78 choke stone on top of pipes
2 inches of sand
2 feet of (6 inch lifts) engineered soil that needs to be boot compacted – NO machinery (we didn’t take into account the boot compaction = $1,000 more in materials)
3 inches of mulch (riser pipe is 6 inches above the mulch – used as an overflow during high rain events)
After

9. Rain Garden Outfall
During a high rain fall event – the riser pipe comes into play
Riser pipe is 6inches above the mulch

10. Rain Garden Acres of drainage: 4-5 Acres Construction Cost: $42,000
$29,225 Excavation and labor for project
$8,100 Materials from New Earth
$1,200 Drainage
$400 Fencing
$1,500 Sod
$1,300 Plants
$275 Irrigation for new plants and sod
Project Oversight: $12,000
Signage Cost: $450
$280 build frame
$156 printing signage
Construction Time: 4 weeks using a 2-3 man team
Cost of materials: $13,000
Cost of project oversight was the key to our success. We hired an professional environmental engineer, Lisa Arceneaux. She helped in making sure that the design was appropriate for the land, specifications of the rain garden, the construction company was following the appropriate rules of installation (i.e. boot compaction of engineered soil), tested the engineered soil for drainage/retention, helped provide maintenance sheets for the structures, etc. I do have copies of these maintenance sheets is anyone would like to see one.
We didn’t take into account the boot compaction = $1,000 more in materials
The bid process took about a month – barrier to overcome was finding companies to bid such a small project.

11. Here, this is the signage produced for the Rain Garden
Here, this is the signage produced for the Rain Garden. This hasn’t been printed and installed to date but will be produced using that same size and frame as the Rain Water Harvesting (4ft x 3ft). You will see that all the signage has a definition of the project, benefits, how it works and definition of stormwater.
Again, the goal of all the signage is to be self explanatory for all individuals visiting the property. To accompany the signage we will be getting a clear pvc pipe to show the multiple layers and the depth of each layer

12. Here’s our Arial map again, and the 6 space pervious parking lot was installed just outside of the main office.

13. Pervious Pavement Before After After
The excavated area is 50 feet long, 20 feet wide and 8 inches deep (phone and electric lines that weren’t found during the line locate)
Setting of the concrete ribbon
Stabilizing filter fabric to keep the gravel layer from embedding into the clay
The underdrain system was necessary because of the clay soils – 4in perforated pipe with 1%-2% slope
8 inches of #57 stone (bobcat was used for compaction – make sure that the stone is 1in below the height of the concrete ribbon)
True Grid snaps together 4ft x 4ft panels 1in thick
#78 pea gravel
5 parking spaces
Sturdy enough to drive a fire truck on it
After
After

14. Pervious Pavement Construction Cost: $21,000 Project Oversight: $6,000
$16,000 Excavation and labor for project
$400 Stabilizing Filter Fabric
$1,400 Gravel
$2,100 TrueGrid Material
$400 Drainage
$250 Concrete Ribbon
Project Oversight: $6,000
Signage Cost: $450
$280 build frame
$156 printing signage
Construction Time: 3 weeks using a 2-3 man team
$5,000 material costs
$3,000 for the concrete ribbon if you hire someone to install it
The bid process took about a month – barrier to overcome was finding companies to bid such a small project.
She helped in making sure that the design was appropriate for the land, the construction company was following the appropriate rules of installation, helped provide maintenance sheets for the structures, etc. I do have copies of these maintenance sheets is anyone would like to see one.

15. Here, this is the signage produced for the Pervious Pavement
Here, this is the signage produced for the Pervious Pavement. This hasn’t been printed and installed to date but will be produced using that same size and frame as the Rain Water Harvesting (4ft x 3ft). You will see that all the signage has a definition of the project, benefits, how it works and definition of stormwater.
Again, the goal of all the signage is to be self explanatory for all individuals visiting the property.

16. Here’s our Arial map again, and our last installation is the vegetated swale

17. Vegetated Swale Before After
This structure is an example of a low cost project.
Here, we used a drainage ditch located just below the Rain Garden. Chose not to do any additional grating or add any additional features
We lined this swale with cedar posts in order to help with the maintenance (we ran into a barrier when a member of the board didn’t like the way it looked and have the maintenance staff mow it) By adding the cedar posts it gave definition to the structure.
We planted rye grass in the late fall and will add in additional seed in the spring.
After

18. Project Oversight: None Signage Cost: $450
Vegetated Swale
Construction Cost: $98
$65 Cedar Posts
$33 Seed
Project Oversight: None
Signage Cost: $450
$280 build frame
$156 printing signage
Construction Time: 3 days using a 2 man team

19. You will see that all the signage has a definition of the project, benefits, how it works and definition of stormwater.

20. Guadalupe-Blanco River Authority
Questions?
Lauren Willis
Guadalupe-Blanco River Authority
Future projects include a 2nd pervious pavement parking lot using pervious pavers and the final structure will be a landscape demonstration plot using different turf grasses and native plants that promote water conservation, proper use of fertilizers and water usage, etc. (partnering with Dr. Jake Mowrer at TAMU in the Soil and Crop Sciences Department)