Master Gardener Presentation - Rain Gardens in Louisiana

Rain Garden Presentation

sources for plant selection

http://rainwaterharvesting.tamu.edu/files/2011/05/Rain-Garden-Plant-List-11-02-09.pdf

davesgarden.com/plantfiles

Draft in progress

Rain Gardens:

Why?

Reasons we can all relate to:

1) Street flooding. (Image ) Rain gardens can help diminish street flooding by slowing the rate at which water flows into city’s drainage system.

2) Diminish subsidence. (Image) Subsidence occurs with water removal because    a) organic matter in New Orleans’ spongy soils oxidize and shrink when the water is removed, and

               b) the particles of that soil collapse onto one another  when water is removed. (cite: http://www.guttertogulf.com/Why-is-New-Orleans-sinking/)Rain gardens can help reverse subsidence by perking water back into the soil, one garden at a time.

               - An article in Nature cited on NASA’s Earth Observatory website used satellite imagery to determine that, in the three years before Katrina, most parts of the city sank 8 mm. per year while some parts – those that received the worst flooding – sank at annual rate of 28.8 mm per year. (http://earthobservatory.nasa.gov/IOTD/view.php?id=6623)

               - Not only do the buildings sink; the pipes sink and crack. This in turn creates more drainage problems and more flooding.

3) Overburdened drainage systems : cities with older drainage systems are in danger of violating the clean water act because they have combined sewer systems, which overflow in heavy rains and can send raw sewage into nearby bodies of water. The EPA is encouraging older cities like New Orleans to develop multifaceted approaches for slowing the rate at which rainwater is dumped into their drainage infrastructure to keep us in compliance with the clean water act. Rain gardens are part of this overall strategy to “think outside the pipe”. Important in New Orleans – we average 64 inches of rain a year.

Other reasons:

4) They’re nice. (Image of Magellan Street Garden)

5) Make use of a resource (rainwater) that is otherwise wasted.

6) Chance to explore native plants that tolerate flooding AND drought.

6) One part of the garden you won’t have to pay a utility company to water.

What Is a Rain Garden?

Dr. Bill Schuster, EPA: “Basically a shallow bowl …. (that) accumulates stormwater runoff” and acts as a sort of sponge.

-        Can be elaborate: e.g LSU Hammond’s rain garden (photo), which drains a paved surface by means of an underground pipe and collects water in a subsurface tank.

-        Can be raised, e.g. Tulane University’s Rain Garden exhibit in New Orleans Botanical Garden (2 images). This has a solar-powered pump that drives rainwater from a retention pond to planters y means of a system of tubing.

-        Can also be very simple: (Image-Groundwork NOLA’s vacant lot garden at N. Prieur and Caffin) A low-lying area excavated so that it will capture significant rainwater, then planted appropriately.

Impervious paved surfaces and creating too much combined sewer system overflows. CSO’s combine stormwater and sewage into same pipe. In heavy rains,. Sewage can overflow untreated into nearby water bodies.

Older cities have these systems. Cities are being driven by threat of running afoul of the U.S. Clean Water Act because they have too much volume

Dr. Bill Schuster – any tool or technology we can use to keep water out of the combined sewer system

Rain gardens one of those technologies

“rain gardens are a very simple and effective way of infiltrating stormwater runoff … potentially soak up a lot of water and function as a sort of sponge

Basically consists of a shallow bowl or patch within a vacant lot … bowl accumulates stormwater runoff

What puts the garden in “rain garden” is that the community plants species that are drought tolerant as well as can tolerate periods of saturation 

Outline in progress

Rain Gardens Presentation: Outline (Proposed/Rough)

I. What and Why:

Why?

Reasons we can all relate to:

1) Street flooding. (Image )

2) Subsidence. (Image)

When you take water out of our spongy river delta soils

               a) organic matter oxidize and shrinks

               b) the particles of that soil collapse onto one another.

               - In the three years before Katrina, most parts of the city sank 8 mm. per year. Some parts – those that received the worst flooding – sank at annual rate of 28.8 mm per year. (http://earthobservatory.nasa.gov/IOTD/view.php?id=6623)

               - Not only do the buildings sink; the pipes sink and crack. This in turn creates more drainage problems and more flooding.

3) Water pollution:

               a)old cities (including New Orleans) have combined sewer systems. When stormwater dumps into them, they can overflow and send raw sewage into nearby bodies of water. This puts us in danger of violating the Clean Water Act.

               b) by slowing the flow of water, rain gardens allow pollutants to settle out. (source: LA. DEQ)

Sum: Rain gardens are part of overall strategy to “think outside the pipe”. Important in New Orleans – we average 64 inches of rain a year.

Other reasons:

4) They’re nice. (Image of Magellan Street Garden)

5) Make use of a resource (rainwater) that is otherwise wasted.

6) Chance to explore native plants that tolerate flooding AND drought.

6) One part of the garden you won’t have to pay a utility company to water.

What Is a Rain Garden?

1. Dr. Bill Schuster, EPA: “Basically a shallow bowl …. (that) accumulates stormwater runoff” and acts as a sort of sponge.

2. Louisiana DEQ: “A shallow depression designed to catch rain from impervious surfaces such as roofs, streets, patios and driveways.”

-        Can be elaborate: e.g LSU Hammond’s rain garden (photo),

which drains a paved surface by means of an underground pipe and collects water in a subsurface tank.

-        Can be raised, e.g. Tulane University’s Rain Garden exhibit in New Orleans Botanical Garden (2 images).

This has a solar-powered pump that drives rainwater from a retention pond to planters y means of a system of tubing.

-        Can also be very simple: (Image-Groundwork NOLA’s vacant lot garden at N. Prieur and Caffin)

A low-lying area excavated in a vacant lot that was already flooding. Now the rain garden captures significant rainwater, drains the rest of the water, and looks kind of nice.

3. Our definition (review with group): a simple, low-maintenance garden designed to capture rainwater and allow it to sink gradually into the soil, planted with natives that can tolerate flooding as well as drought.

II. Design

Gary’s powerpoint showing his lot, orientation to sun, calculations of water capture.  (Can't upload, sorry.)

III. What to plant

Plant Selections (from Terry) 

IV. How to build it (need graphics)

Emphasize solutions for city-dwellers, do-it-yourselfers, affordable. 

Biggest problem is digging - clay is heavy. 

Use excavated soil, esp. clayey soil, from depression to build up retaining wall/berm on lower/street side of garden. 

Minimum ten feet from foundation, per LA DEQ. 

Depth should be 3-6 inches. Increase retention capacity by building in lower layers of coarse material (construction debris, gravel, sand) into which water can perc. 

Planters as possible solution to water collection at base of downspouts. 

Contractors: EcoUrban LLC has most experience. 

Guidance: Groundwork NOLA will advise homeowners for a fee.  Bayou Rebirth, other organizations may also offer homeowner guidance, will check. 

V. Maintenance and cost

Rosalie
- Proper plant selection biggest key to making it low-maintenance

- Will S&WB give you  a break on your water bill if you install a rain garden? I have asked for a good contact at SWB and will forward if I get. 

VI. Conclusions
a) Summary of ongoing city and federal efforts to promote rain gardens: S&WB funding for education, City of N.O. 6.2 million - 35 year master water plan
b) handout: map and addresses of rain gardens you can visit
c) handout: GNO soils map with key to soil types. 

Images for presentation

Why rain gardens? 1. Street Flooding

Why rain gardens? #2. Subsidence

Rain Garden at LSU Research Center, Hammond

Satellite image of subsidence in New Orleans, 2002-2005

Magellan Street Garden, Algiers

Tulane Architecture School's water garden in New Orleans Botanical Garden

detail - water delivery in Tulane garden in NOBG

Groundwork NOLA at N. Prieur and Caffin

Sites and other sources of interest

This is a release from La. DEQ that identifies dispersal of pollutants as an important reason for establishing a rain garden, and also gives basic guidelines that are a little looser and more suited to Louisiana than the University of Wisconsin guidelines might be. 1 page.

http://nonpoint.deq.louisiana.gov/images/education/FactSheets/Pub2994-J%20NPS%20Rain%20Gardens.pdf

2014 article from New Orleans Homes and Lifestyles identifying several completed rain gardens and their locations, as well as some local contractors.

http://www.myneworleans.com/New-Orleans-Homes-Lifestyles/Spring-2014/Rain-Gardens/

New Orleans soils map (Data from NRCS but produced by Waggonner & Ball)

New City of New Orleans water management plan announced; city planning also makes changes to encourage homeowners to capture rainwater (9/2013)

http://www.nola.com/politics/index.ssf/2013/09/water_in_new_orleans_new_appro.html

2014 rainwater management programs at Parkway Partners, other agencies to be funded by Sewerage and Water Board (Advocate, 8/2014)

http://www.theneworleansadvocate.com/home/10037357-171/classes-teach-ways-to-manage

September 2014 NOLA.com article on private homeowners/architects Ramiro Diaz and John Klingman and their rain gardens; also mentions Parkway Partners' Green Keepers training.

http://www.nola.com/homegarden/index.ssf/2014/09/a_natural_way_to_fight_street.html

Invaluable site on the the City of New Orleans' plan for adopting a new relationship with water

http://livingwithwater.com/

U.S. EPA research hydrologist Dr. Bill Schuster's research on how rain gardens in vacant lots can help slow the impact of rainwater on older urban drainage systems. 

https://www.youtube.com/watch?v=Dh38rZvyGxg

Posted with Blogsy

Plant selection - notes and images

9/9
From Terry

Suggested plants for a Rain Garden in our area (Louisiana)

The following would be recommended for a Full Sun Rain Garden

Aphrodite Althea – Hibicus syriacus

Arrowwood viburnum shrubs – Viburnum acelrifolium

Beautyberry – Callicarpa americana

Blue flag iris – Iris virginica var, shrevei

Butterfly bushes - Buddleja marrubiifolia – LA Super Plant

Copper Iris – Iris fulva

Elephant ear plants - Colocasia

Lilyturf – Liriope muscari

Louisiana Swamp Iris varieties: “Wild Cajun”, “Cajun Sunrise”, “Bayou Sunset”,

“Full Eclipse”, and “Sun Fury”. There are hundreds of varieties – in 1941 Society forLousiana Irises was formed.

Marshmallow – Hibicus moscheutos

Marsh marigolds – Caltha palustris var, palistris

Pickerel weed – Pontederia cordata

Pitcher plant - Sarracena

Rush – Rhynchospora colorata

Swamp Hibicus – Hibicus grandiflorus

Swamp Milkweed – Asclepias incarnata

Swamp Sunflower – Helianthus angustifolisis

Sweet shrub - Calycanthaceae

Two-winged silver bell – Halesia diptera Ellis

Wild bergamot – Monarda fistulosa

Winter berry holly – Ilex verticillata

Sources:

Jan Goldfield, The Pondlady – jan@pondlady.com

LSU Research Center in Hammond

Theamericanirissociety.blogspot.com

Clemson.edu

Magnoliagardensnursery.com

Rockydale.wordpress.com

I would like to show a picture of these plants either before or after the name. They can be found on the internet, I just don’t know how to retrieve them to place with the names!

Hi - found this posting from a gardener in Slidell, dated 2007. She has postings through 2012; maybe she can speak to you, or will respond to an e-mail about plant selection?
http://pondlady.blogspot.com/2007/06/plants-for-your-rain-garden.html


(From Terry - posted to Facebook page 8/26)

Terry Francis Pizzalato I will contact someone at the LSU AgCenter in Hammond about suggested plants for use in the rain garden. I will offer suggestions for the area that Gary will design. I'll post when I get some scoop! See you all Thursday!

(To Terry on 9/2/2014)

Dear Terry,

I’m attaching one photo of the water garden at LSU Ag’s Hammond research station, taken today. The plants I noted in the garden were as follows:

Blue Flag (large clump with spearlike leaves in foreground of photo)

Two-winged silver bell (behind the iris)

Pitcher Plant (these were not doing well – they looked kind of burned)

Pickerel weed (looked great)

Winter berry holly

Rush (Juncus species)

Copper iris (these looked dead)

Beautyberry (not doing well)

Button bush

(?) River Birch (the tree planted in the center)

There is also a fairly lush shrub just to the left of the blue flag in the photo. I was not able to identify this plant. It has camellia-like leaves but did not have buds, so I don’t think it was a camellia.

The rain garden at this site is at the elaborate end of the scale for rain gardens. Allen Owings, who led our tour today, described it as follows: a drainage pipe collects water from the parking lot (about 50 yards distant from the rain garden) and sends that water to an underground reservoir that lies below the rain garden. When the reservoir fills, it overflows at the top, creating a temporary pool in the garden. This is different from most of the models we’ve seen, wherein water flows directly into the rain garden from above, either by means of a pipe,  by collecting water from sloping ground, or by some combination of the two.

Dr. Owings was very approachable and would probably be delighted to answer any questions about appropriate plantings or about the design of this particular garden, or to direct you to whoever developed the garden. His email is aowings@agcenter.lsu.edu . He lists his phone numbers as  (985) 343-4125 (land) and (225) 603-8096.

Other group members, please chime in if you have any additional information about this garden from our tour.

Lili

LSU Hammond Rain Garden

2014/09/08: Below are images taken today at the Common Ground Relief Wetlands Restoration nursery on Deslonde Street in the lower 9th ward. All of these trees are suited to wetlands planting and would presumably work in a rain garden. I could identify bald cypress, pond cypress, bay tree and I think some kind of gum tree. There's also a tree that looks like a kind of magnolia. Perhaps Lee and Sarah could help identify if group members don't know. 

common ground nursery - gum trees (?)

Common Ground nursery - magnolia?

common ground nursery - bay

There's also a great list of suggested plants for rain gardens on the Texas A&M website, rainwaterharvesting.tamu.edu