Drought, aftermath, and remediation

As a scientist, I like to use my skills to help others. Right now, I'm working on a drought "action plan" to help save species and diversity at one (and possibly two) Audubon centers. I've got what I think is a workable plan, but want some feedback on what I may have missed/not thought about.

Here's the situation: brownfield remediation site, nine ponds, after 4 years we had decent biodiversity (including mussels, crayfish, and fish in the ponds) and were getting ready to get rid of invasive plants (Johnson grass, privet, etc.) Then the drought hits.

There's no significant rain in the forecast.

Six of nine ponds are completely dry (we've lost fish and a lot of other things.) One pond is very saline and has been 'fished out" by birds. There are some turtles but the pond won't last another month without significant rain. Two still have fish and mussels (and I spend one day of the week, more than knee deep in mud, throwing mussels into the deeper waters to save them. Yes, really.) The grass (including invasive Johnson grass) is almost all gone (the ones still doing well are native prairie grasses like switchgrass and side oats gramma.) Trees are going into drought shock, and we're losing lots of little saplings. Currently there's lots of grasshoppers, but I'm not sure how long this will continue.

And bird migration season is beginning. We're on the Central Flyway... more than half the migrating birds pass through here.

Severe erosion will uncover the toxic waste that's buried here and it'll go right into the river.

What I'm trying to do (and need some thoughts on) is a list of areas that WILL BE PROBLEMS when the rain comes back. I have three rain scenarios:
1) mild - rains return but on the order of 3-5 inches per month (normal for Dallas) and no significant flooding occurs. Ponds gradually fill
2) moderate - drought is broken by a hurricane in Houston and we get 5-8 inches suddenly dumped in one storm (filling most ponds) and rains return more or less as normal after that.
3) severe - hurricane causes rain, drought continues after that until spring rains and we get violent storms (multiple (3-8) flood events over a seven month period. Ponds fill and then dry.

Here's what I've got:
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problem impact mild rain impact moderate rain impact severe rain
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soil loss some erosion moderate erosion high erosion, loss of EPA work
ground cover loss some invasives moderate loss lose most of our grass cover
migration stress some problems moderate problems possibly significant bird loss
tree loss low some erosion loss losing more than 10% of our trees
nectar plant loss unknown unknown high
berry (food) loss ---can't mitigate. already happening ---- high for next year
fish loss moderate moderate high
mussel loss * moderate low high
turtle loss ** low low unknown
water plant loss moderate moderate high
fire threat *** low low high
saline soils ---already happening ------------------------- remediation needed

* mussels clean poisons from the water. We'd like to see them around
** hard to say. Turtles "brumate" (a form of hibernation) and can do so for months.
*** lots of wooded areas plus some neighborhoods, but this IS in a city and containable.

Question: what else should I be considering that MAY be trouble points (looking for things that may need to be taken care of... this isn't the "and here's what we do about it." I'm just defining the danger points.

What other problems can you identify?

Good suggestions will end up in the "battle plan". Once I'm sure I've got a good handle on the major situations, I'll tweak the "here's what we do about it" action plan.


NOTE: I recognize that this is a "wicked problem" or possibly a "super wicked problem." I'm taking that into account.

Nature is both resilient and remorseless... take it from someone who lives in the middle of it.

If I am understanding your situation correctly, the problem is that the sample size of nine ponds is too small to be truly indicative of a larger natural setting. There are ways to correct this, but they are somewhat expensive:

• Wells or emergency irrigation to allow an influx of water during drought. In a larger setting, localized droughts are counteracted by normal weather elsewhere. If one small area dies off, the return to more amenable weather patterns brings in a new influx of flora and fauna from the surrounding area to repopulate it. With smaller research size areas, this is a disaster instead of a minor setback. So you have to have some way to mitigate damages caused by localized phenomena.
  
  
• I'd hire a civil engineer to examine the water flow patterns. If you do get torrential rainfall (like I am getting right now
  ), the area will need some way to remove excess water through spillover. A good engineer can suggest specific corrections in terrain to minimize damage from such spillover (erosion, etc.).
  
  
• I would also examine if some aspects of native species have been overlooked. Plant life that appears rather sparse above ground can actually do much to prevent erosion if the root systems are complex enough. You may need to make some adjustments to the purely natural setting, such as transplanting or temporary irrigation, to get things established into a self-sustaining role.

I'll keep thinking on this... good luck! Just remember that nature is also a formidable enemy but an industrious ally... make her your ally, not your enemy.

TheRedneck

I do know that down here, where the water table is anywhere from 0-15 ft below ground, what they tell you to do if you want a self-replinishable pond, you have to dig part of this pond to be 25 ft deep, roughly. Those survive the 2-3 month droughts we occasionally get right before "monsoon season". So, for these ponds of yours to be self suficient, they'd have to be deeper than the water table. When some areas's water table is an 8 story building down, this isn't practical. But, if you have a fairly local spring source, you could run underground pipes to the ponds (with shut-off valves, please), ensuring that they have a chance to survive. It can be expensive, but we pipe oil all across this country, so it's not impossible.

As for the toxins, set up one of the ponds with toxic sourced water and don't eat the critters from it. Experiment on finding plants and whatnot that filter out the chemicals, improving the water, or set up your own chemical treatment plant. I mean, if you can buy a house filter that cleans out the really nasty stuff from local sewage dumps and makes it so you can drink it safely, I'm quite sure they have the same for large scale operations. If this is too expensive, I'm sure there's grants and whatnot out there for it.

*shrugs*

Something I have been thinking about.
Are your ponds and surrounding areas experiencing cracks in the ground?
What would happen if you did have a significant rainfall,say from a tropical system?
I would think that there would be significant erosion, if not on level ground.
From the water filling and flowing through those cracks in the ground.
I have an uncle with a pond going through a similar situation.The cracks are troubling ,as I fear a heavy rainfall and erosion of his dam.

Other than that,nature will rebound like it can,in surprising ways.
Sorry to hear of such a devastating drought you and yours are enduring .
Pray for rain.

Thanks for the responses, folks -- I know this is a head scratcher.

This isn't my land. I'm just a park volunteer who is also a scientist who specializes in complex problems.

The park provides habitat and food sources for some wildlife.

The issue of cracks is interesting. The ponds aren't dammed channels. This a "brownfield remediation site" -- EPA forced Dallas to clean this site, which had been severely polluting the air and water in Dallas (tire fires, dumped chemical drums... illegal landfill site.) The ponds are artificial (they put down gigantic pool liners and the ponds are formed on those) so the water table isn't an issue.

Texas blackland clay is a pretty wicked soil. When it gets wet, it becomes muddy (stinky!) black clay. Once the water is gone, it cracks -- I measured one crack at over 2 feet deep.

Looking for the deeply cracked areas is an interesting thought, though, and I think I should go see where the deepest ones are and which areas are the most cracked. Some of the soil is "sterile clay" ... orange brown dirt and I'm not sure how erosion proof it is if the grass goes away.

Cracks. Interesting suggestion.

I did check on the recommended depth of ponds in this region, and the Ag commission says a minimum of 8 feet... when they were started I believe that, most WERE in that range. Four years later, I'm not confident that the ponds with cattails in them are 8 feet deep... I suspect it's closer to 4 feet. Cattails cause silting problems, by the way.

Check pond depth -- good reminder. (tired grin -- I can tell you how deep the MUD is! I have the photos to prove it, too -- I was out there rescuing bivalves!) Need to find a way of surveying that (and measuring angle of tilt of the land.)

They won't be able to afford contractors to deepen it and they don't have the volunteer manpower to do it.

Many thanks to those of you answering... you've given me things to think about (yay!) and if I had a team of a hundred, I could answer many of those in a week or two. If you have any other ideas, please do mention them.

Originally posted by TheRedneck

I would also examine if some aspects of native species have been overlooked. Plant life that appears rather sparse above ground can actually do much to prevent erosion if the root systems are complex enough.

The (native) switchgrass is doing well, thankfully... their roots can go down into the soil as far as 6 feet deep. But the nature center isn't going to irrigate... they can't afford it. It was done the first year to help establish the EPA mandated seeding and tree planting, but after that, the money to water it all was gone. Volunteers have been watering some troubled areas but that's been by hand (as in "get out the electric cart and haul buckets".)

And Dallas is on watering restrictions... that's how severe the drought is.

But... I'm thinking I should go harvest all the switchgrass seed and sideoats gramma I can get my hands on to start making ready for the rains. I'll check other species as well. I think there's some threeawn out here but I'm not sure how it's doing.

reply to post by Byrd


Hi byrd,
A few questions if I may?
How big/wide are these ponds?
if your removing invasives, what is being put back as cover in its place?
What type of trees did you guys plant? Whatever was close by or Waterwise?
_edit_
The things that concerned me the most there were
1. The contaminants
2. The drought
3. lack of a seperate water source in order to sod, grow, and remove.

I was going to suggest covering the ponds, planting a type of grass/plants and trees that require less water but it seems money is an issue, Im assuming this land program began with a grant and the dumping entity is pretty content with not helping with funds for the cleanup.

Well, I'm a Cajun, and I can tell you all we have down southwest of NO is clay. This is roughly the same type of soil and depth to the water table--and we dig to 25 to tap into groundwater. But with a plastic liner it is out of the question. Hrm, to deal with the contaminates. If they are oil based, there are some deep sea critters that eat that mess.

Originally posted by Nephalim
reply to post by Byrd

 

Hi byrd,
A few questions if I may?
How big/wide are these ponds?

It varies. They're all different sizes. I haven't done an estimate on how much water they hold but (thank you for reminding me!) I need to do that.

if your removing invasives, what is being put back as cover in its place?

The focus has been on invading shrubs (privet and sweet willow), and nothing's been planted (the light lets grass come in.) Work on the Johnson grass was just starting, with the mapping of "where is this stuff (all over the place, actually.)" We had been actively planting native Texas prairie grasses, including switchgrass, sideoats gramma, prairie threeawn, bushy bluestem, little bluestem, and big bluestem. There's also some 'witch hair grass' and dropseed as well as buffalo grass.

What type of trees did you guys plant? Whatever was close by or Waterwise?

The folks are not pleased with the trees planted by the EPA. A number have died, though this may be from misplanting (the plan was approved, it was subcontracted to someone, who subcontracted labor... probably from the 'day labor' pools and not experienced nurserymen since the trees had to be put in quickly.) However, they are natives including red oak, bur oak, Mexican plum, Eve's necklace, and cypress (native to Texas.)

I should add that part of the trees in question include an old hardwood bottomland forest (trees up to 250 years old, so we saved but didn't plant them) and Virginia juniper (grew up after farming ended on the land -- trees are up to 70 years old.)

The things that concerned me the most there were
1. The contaminants
2. The drought
3. lack of a seperate water source in order to sod, grow, and remove.

The contaminants were put in a "sanitary landfill" (basically given the correct treatment) but it's a "closed landfill" and although it's being monitored for methane and methane's being collected, I'm not sure about the grass planted on top of the landfill (it's a "no human visitors" zone... so monitoring it is difficult. This isn't because the land is poisoned, but to prevent erosion (people walking around, creating trails, erosion tunneling into the landfill covering.))

I was going to suggest covering the ponds, planting a type of grass/plants and trees that require less water but it seems money is an issue, Im assuming this land program began with a grant and the dumping entity is pretty content with not helping with funds for the cleanup.

Oh, the tale of this is one that makes my blood boil. The "dumping entity" is behind bars... was run out of Ft. Worth (next to Dallas) for running an illegal landfill. He bought the property and said he was going to sell gravel (it's on the banks of the Trinity River, so it has gravel) and within one week (yes, one week) he had gone to everyone who sent garbage to the Dallas dumps and offered them cut rates to throw the garbage on this land. Within a month, the local residential streets were jammed with (get this) TWO HUNDRED TRUCKS A DAY!

(This info comes from newspaper reports and lawsuit and documents.) For 30 years (yes, thirty) the people complained but this was a poor section of town and the attitude was "it's them whiny Blacks again" (I have a real RANT about this that I won't go into.) The dump caught fire twice -- the fires burned for 7 months (tire fire) and then 3 months. Appeals to the city and state went unheard. Finally the EPA got involved, did the smackdown on Dallas and made them clean the site up. Terry van Sykes had all his money taken from him and was thrown in jail.

So they did an EPA cleanup, partnered with Audubon, put a nice building up there... and gave them money for a staff of SEVEN people. Luckily they have the world's finest volunteer coordinator, and there's a corps of about 30 of us who teach schoolkids (we get 200-300 students every week for our programs) and guide hikes and do citizen science and tend the property.

...and that's the story. But there's no money for much of anything.

Interesting that you mention the "sod and remove"... I have been thinking about the possibility of putting in some sideoats gramma (as a test) in the muddy areas and seeing if it'll grow... then grabbing it and transplanting it when the rains start.

Originally posted by CynicalDrivel
Well, I'm a Cajun, and I can tell you all we have down southwest of NO is clay. This is roughly the same type of soil and depth to the water table--and we dig to 25 to tap into groundwater. But with a plastic liner it is out of the question. Hrm, to deal with the contaminates. If they are oil based, there are some deep sea critters that eat that mess.

Right now they're contained... this is basically an EPA cleanup/sanitary landfill that's turned into a park. I'd like to get bivalves back into the ponds just to help in case there's a problem.

And yeah, your stinky clay sounds like MY stinky clay! I think we have to go further down to hit an aquifer here in Dallas... not sure, though, since we get our water from lakes.

Hi Byrd, sorry don't have any answers, but I do have another problem for you: is this drought likely to be a one off or might it return next year or in 2 or 3 years time? Maybe worse next time? Or, indeed will it just continue?

Don't want to take this thread off track, but there are suggestions that this might be the case. ie:

Southwestern US heading for 'perpetual drought'

Hot With Decades of Drought: Expectations for Southwestern United States

Prepare for Hotter and Drier Southwestern US, Climate Experts Urge

Persistent Drought to Linger Across Southern United States

(it looks like La Nina in returning and some have suggested that we may be entering of perod of more frequent -ve ENSO events)

La Nina Watch Means More Dry Weather Possible For Southeastern United States

Something which I think should be given consideration with regards the long term viability of the project.

reply to post by Byrd

This may sound like a silly proposal since I am not familiar with the area, but it needs to be considered just in case: are you close enough to the Trinity river to put in some sort of temporary piping? PVC is cheap and you could probably get someone to donate an old pump.

Without water, a lot of the flora is toast.

The really bad news is that nature never cares what we want to do with a plot of land. Nature will decide in the final reckoning exactly what goes there. If it becomes too dry, drought-tolerant plants will take over; if it floods, floodplain plants will thrive. The best we can do is try to recreate the conditions favorable to the use we have planned, and unfortunately that usually requires some cash outlay.

I really wish it were closer to me; I could maybe help scrounge up an old pump that had a little life left in it and make some specific suggestions for handling flood waters. After all, making silk purses out of sows' ears is what rednecks do best.

TheRedneck