>>It's good old grass.

This is exactly what we want.

We want grass, Kentucky 31 Fescue, that's gonna put down good roots and hold the soil in place so when the water is running down the face of this dam, it's protected with green grass and lots of roots.

>>So, this garden does have engineered soil in it.

So, about 18 inches of the soil was excavated, and a soil mix was added that was mostly sand.

Virginia Clay is not great at infiltrating sometimes, so sometimes we need to have those soil amendments that can help.

>>Production funding for "Virginia Home Grown" is made possible by.

(birds chirping) (upbeat music) >>Welcome to "Virginia Home Grown."

The long summer days of July are perfect for celebrating the garden, with trays of fresh tomatoes, and bouquets of flowers on the table.

While peppers and lantern thrive in the heat, many other plants need extra water.

Today, we're highlighting water and its role in our gardens and landscapes.

But before we get started, I wanna remind you to send in your questions on our website at vpm.org/vhg.

A little later, we will visit Hone Quarry Dam in Rockingham County, to learn how flood control structures work, and how they protect us.

But first, I met with Blair Blanchette at Rappahannock High School in Richmond County, to see how rain gardens protect waterways, by collecting runoff.

Let's get going.

>>Blair, all I see is asphalt.

All I can think about is what happens when it rains?

>>Yes.

When that rain hits the land here, it's gonna pick up all of the pollution on these roads and sidewalks.

So the emissions from our cars and the sediment, the dirt that is also on these surfaces, and it'll enter a storm water system, and flow into the closest river that we have here.

>>You know, people just don't realize how much pollution comes from the hard surfaces in our communities, but we have this beautiful planting here.

What is it about?

>>Yes, we are in Richmond County at Rappahannock high school, and we've got a rain garden behind us that was installed in partnership with the friends of the Rappahannock and with an environmental science class.

>>Fantastic.

And what's the purpose of this rain garden?

>>Yeah.

So rain gardens are plantings that treat runoff from impervious surfaces.

So, we do have parking lots around us, some ball fields, and a little bit of turf grass that can be impervious as well.

>>Exactly.

You know, with sidewalks and things, people don't even realize grass is impervious at times and can equally provide runoff.

But this rain garden here, you know, sometimes it has water for a short period of time, but other times it's dry.

Can any plant be used?

Because this is a very nice combination of plants.

>>So, rain gardens use native plants that are sometimes called wet foot, dry foot plants.

>>Mhm.

>>So, they can tolerate standing water for a little bit of time and be dry for other parts of the year, which we have frequently in Virginia, both.

>>Yes.

>>And you can see, it has a little bit of a grade to it, a little dip, so that that water will pool off of the parking lot, And then infiltrate slowly.

So above us, we have a Willow Oak.

>>Yeah.

>>We have some Red-osier Dogwoods, panic grass.

There's some Lilacs behind us as well, but there are lots of different plants that you can pick.

So, we're missing some perennials that could be here if you wanted it.

>>Add a little splash of color.

Yeah, >>Exactly, and you could have those seasonal colors if you'd like.

>>Well, what about the soil?

Is there anything special done to the soil for a rain garden?

>>Yes.

If you don't have a great infiltration rate which can happen with Virginia Clay, >>right.

>>You can amend the soil with a rain garden mix or a bio mix.

>>Mhm.

>>That will be a large portion of sand, some top soil, And then sometimes some pine fines, things like that.

>>But if you can't afford the bio mix what could you do to your home soil?

>>Yes.

So you can amend your home soil with compost or with a mix of compost in sand to help with that infiltration rate.

We are trying to infiltrate water, so anything that can permeate better than Virginia Clay.

>>So break it up, so those roots in the air and the water can get all down into that soil.

>>Exactly.

>>And replenish the water table.

>>Exactly.

>>Yes.

Now, if it rains real heavily, you know all that soil, does it float, does it go away?

You know >>No it'll stay in place and the roots will help with that too.

And the micro communities on those roots will help keep it in place.

This system does have an overflow drain.

It is engineered for a particular storm but if we get a really big rain, it has somewhere to go.

>>Oh, that's great.

What else do the plants do though?

Cause I know our water is not pure, it's not clean.

>>Yes.

So plants of course have so many wonderful benefits.

They treat pollution, they will take up that phosphorus and that nitrogen, use it to grow and create that habitat for pollinators and food.

They can process heavy metals sometimes depending on the plant.

And again, they're just beautiful and create that sense of place.

>>This is a beautiful rain garden.

So who truly is involved with taking care of it?

>>So Rappahannock high school of course, and the environmental science students installed it and they continue to maintain it.

And I also like to thank friends of the Rappahannock for facilitating this VCAP project.

>>Oh, what a great combination.

So they're getting mentored by, ah I'm just so excited about that.

Who else can get involved with this program and how do they apply?

>>Yes.

So the reason that we are here in particular, is this is a VCAP project.

So I run the VCAP program the Virginia Conservation Assistance Program through the soil and water conservation districts.

So anyone that has a property that might have an issue can apply.

So it could be places of worship, businesses, homeowners any of those properties qualify.

>>So you'll help me.

>>Yes, and so we have district staff that go out and can have a site visit with homeowners and discuss what issues they're having.

Maybe it's lots of runoff, maybe standing water, bare ground, >>Mhm.

>>these different issues that can cause pollution to run into our rivers and streams.

So we wanna intercept that, >>right.

>>And prevent it from reaching there with all of that pollution load.

>>What a beautiful way to intercept it.

>>Yes, of course.

>>And also to help replenish our groundwater supply.

>>Absolutely.

>>That's fantastic.

So what are the, I'll say, the steps in getting connected with the program?

>>Yes.

So I would of course go to our website.

So, Virginia association of soil, water districts website.

and you can find your district staff.

So the different counties have different district staff.

You'll set up that site visit and they'll come out and discuss the issue.

And we do have an application process, and that application process will approve you for reimbursement for these practices.

>>A percentage of it or the whole thing?

>>A percentage, yes.

>>Okay.

>>So it depends on the practice, exactly how we break that down, but we want to protect the water quality of our rivers and streams.

So, we are trying to encourage homeowners to take up these practices.

>>Fantastic.

>>Yeah.

>>So this is a statewide offering?

>>It is, I will say there are some cities that are not in districts.

>>Okay.

>>But we're slowly incorporating them.

>>Okay.

>>And so if that is not available to you right now, maybe we can have a conversation about it and see if we can bring some cities on board.

>>That'd be great.

>>Mhm.

>>Yes.

>>And I will say we have a variety of practices.

So this is one of them and it is one of my favorites.

I do love rain gardens, but we also can sponsor rainwater harvesting systems, permeable pavers, vegetated swales, things like that.

So whatever is the most appropriate for your issue and for what you'd like to have.

So if you like those plants, we can talk about vegetated offerings.

>>But maybe you just want a very nice rain barrel.

>>yes, yes.

>>Or maybe you want that permeable paver in your terrace instead of the hearth stone.

>>Yes.

>>So there's many options and people there know what they're doing.

>>And just to the plants, if you have a preference for certain bugs that you like, or colors, or you really wanna see something bright in the fall.

>>Yeah.

>>Our native plants are incredible.

And so you can find a design or a contractor that'll help you with a design that meets your needs.

And people will never know that it's functioning to treat storm water unless you tell them.

>>Exactly.

>>You could drive by this and say, oh that's really nice and beautiful and adds to this site.

That's otherwise just a road and some sidewalks and never know that it's doing something really incredible.

>>This is fantastic.

Cause as we all know, our rainwater falls on these hard surfaces, and it rushes into our storm water systems, and it ends up at our local river, which ends up at the bay.

>>Mhm.

>>I love it when students get involved in the project such as this where they get out and they get involved, they get their hands in the garden, they get their hands dirty, and they also learn the importance that this garden plays in protecting our environment.

So I just, I thank you so much for coming and sharing the program with us and also for showing off the work of Rappahannock high school.

>>Yeah.

Thank you.

>>This has been wonderful to highlight such a success story in such a public space.

>>You know Blair, it was so great to visit a school taking advantage of the VCAP program and to educate students and learning about the many ways property owners can participate in the Virginia Conservation Assistance Program to manage rainwater on their site.

And now Blair is here with me to demonstrate how engineered soils allow runoff to infiltrate the ground helping to replenish the water table.

But before we get started, remember to send in your gardening questions on our website at vpm.org/vhg.

Blair, you've got some interesting things here.

I mean, not many people come with a soil auger.

(both laughing) So what do we have here?

>>Yes, so we are gonna now look at everything that's below the rain garden.

So, I took this soil sample earlier today at a site that was experiencing a resource concern that we might address using a VCAP project.

So this looks like Virginia Clay, and you can even see it's started to dry the way Virginia Clay does.

We have a tiny sand layer in here, but this type of soil can be problematic, because it doesn't allow the water to infiltrate.

>>Right, and with rain gardens we wanna install a rain garden in our property, we wanna make sure that we're collecting the water but also that it's infiltrating to feed the groundwater.

So this first step of using an auger to kind of test the soil, is a vital one.

Well, what did you find with this test here?

>>Yes, so my first impression is this might not infiltrate particularly well.

And whenever we are looking to install a VCAP project that's going to infiltrate, we might do an infiltration test.

We should do an infiltration test.

The district staff can help the landowner with that.

We would dig a test hole about the same depth as the practice, fill it up with water, let it drain, fill it up again.

And then measure that rate of infiltration.

>>Do you measure the rate per hour, or per like half a day?

You know, cause you are talking about importance of rain gardens and managing our water on that landscape.

So what speed do we want it to drain?

>>So we want half an inch an hour, so you'd measure every hour.

And depending on the result that you get, we could amend the soil to help it infiltrate and make a nice place for those plants that are gonna help it infiltrate too.

>>That would be nice.

Now, if we end up with heavy soil, like what do we have here?

We've got some heavy clay here and then we have the sand.

How do we address it, if this is our soil situation?

>>Yes, so with this soil, we could amend it.

So, what we've got here is this clay.

So I've got another, this is just a broken down version of that clay and you can see it likes to stick together and it's still damp from this morning.

It's still holding onto that water.

>>It's very sticky.

>>Very sticky.

Yes.

>>Yes.

And so clay while it's great for agriculture, for infiltrating and draining soil in a, I'll say, a best management practice for storm water, it really is not what you're seeking.

>>So I took the same soil that I took out of this sample right here and I added some compost.

>>Oh, that's beautiful.

>>It's very rich.

Gives you the impression that it's gonna make these plants happy.

So this is an example of something we would ask homeowners to do, or tell homeowners they could do to help with that infiltration.

Very accessible.

>>And what percentage of compost did you add to the clay to get it that beautiful?

>>So I'll admit, I had about a 50 50 ratio.

It's a small sample there.

>>Yes.

That's a lot of digging and tilling in that regard.

Which, speaking of, how do you determine the size of a rain garden for a property?

Does somebody come out and measure it?

>>Yes.

So our district staff can also help with that as part of the application.

So it's based on the area that's draining into the rain gardens.

>>The hard surfaces in being like roofs and driveways, walkways and things.

And what other hard surfaces could be out there that we really don't think about?

>>Yes.

So turf can become a hard surface.

In a really heavy rainstorm that turf will lay down and act like pavement.

>>I think we've all seen that.

Yes.

But you've got another container of soil over there.

What's that one?

>>I also made this soil sample.

So this is a mimic of a bioretention mix.

So you can purchase bioretention mixes and they all come premixed, but I made this.

It's about 60 to 70% sand and about 20% compost.

And then the remainder is pine fines.

So it's gonna allow that water to infiltrate really well.

You can see how much looser it is than our clay that we had earlier.

>>Right.

How fast do you want it to drain out?

If I have a big rain event in my yard and I have a rain garden in my front yard that's collecting the water off of my roof through the gutter system and such.

How long do I want that water to stay in that rain garden?

>>So typically less than 24 hours.

They shouldn't become a mosquito issue and that water's not gonna stand for particularly long.

So it's just enough to keep the plants happy and have that water infiltrate.

>>Down into it.

What happens if it's an excessive rain event with my rain garden and it starts overflowing.

Is there a concern about that?

>>So they can overflow, they're built to one inch storms, and that's okay.

Some of them can have under drains that can help drain that water away too.

>>So that it prevents the overflow.

Okay, well, we've got beautiful soil now in our rain garden and we've had expert out, they've kind of surveyed the yard.

They've put together a plan for us and we've done the digging and we've put in the soil mixtures.

But filling it with plants, what type of plants do we wanna put in our rain garden?

>>So all of our plants are gonna be native plants.

They are happiest here.

They are comfortable with the climate that we have, but these types of plants are fine with being wet for 24 hours.

So these wet foot, dry foot plants.

>>And there's a whole list that's provided to choose from?

>>Yes.

So the district staff can help.

Contractors can help you make a plan.

And we have a native plant list available as well.

>>Speaking of, we've got a few native plants here.

>>Yes.

So we've got a couple and I've divided them by sun and shade, different plants.

So these are some of my favorites.

This is River Oats and it's a great grass.

They're gonna have those roots that are gonna help the water infiltrate.

And they get these really adorable nodding seed heads.

And so if you are a florist, they're also nice for displays.

>>They do dry very well.

>>Yes they do.

>>They do.

And the other thing is they're actually used in the beach to help hold sand dunes.

So that's how deep those roots go.

>>Exactly.

>>Do you want to be concerned about, really the depth of the roots?

Do you want them deep?

>>Yes.

So having those deep roots is gonna help that infiltration.

These guys are a little more fibrous, but for instance this Beebot Blossom has a tap root, so slightly different root structures.

>>Okay.

And what about the Coreopsis?

>>Oh, so yes, our Coreopsis friend here, this is Mouse Ear Coreopsis and it just has these really beautiful petals that have little notches in them.

And this guy had about 15 or 20 blooms on him the other day and just decided to drop them prior to this, but you can get an idea of what this would look like.

And again same thing, would have great roots that would help infiltrate.

>>On the shade side, And we don't have much time, so we've got a hurry.

You have one of my favorite ferns here for the partial shade, the Maidenhair Fern.

And then what's this one here with the bloom?

>>So, Foam Flower or Tiarella Cordifolia, and all of these, including the Dicentra, will spread but they help with that infiltration too.

>>Interesting.

And then finally this here.

>>Yes, our Bleeding Heart.

>>Yes.

This is actually a plant that will die back.

>>Yes.

So on our planting plan for a rain garden, you can put things that die back.

As long as you have other things that are gonna really help that infiltration.

So you can have the beautiful on the edge the functional in the middle.

>>And that's nice to know that these rain gardens can be beautiful as well as functional.

So Blair, thank you so much for bringing in and showing us about soils and the importance of rain gardens and how they protect our ecosystem and our waterways.

>>Thank you.

>>And how we can manage them right on our property.

And that's really important.

So thank you.

And now we're gonna get ready to answer your questions but first we have a tip from Cerone Hamlin on how you can get started using drip irrigation in your garden to help save water and time.

(melodic digging sounds) >>In the heat of the summer, as gardeners we spend a lot of time watering and using a lot of water.

We can save some water and time by hooking up a drip irrigation system.

This system is very easy to use and easy to set up.

It can plug right into your normal garden hose and you can use different emitters and adapters to accomplish what you need.

Like this adapter here, this is more of a spray adapter so that you can use it in bigger containers.

Or if you're doing a little overhead watering something like this, you could use as more of a mist system for overhead watering.

These drip lines just connect into this end here so that you can run multiple lines to different containers.

Easy to hook up the system.

I've already had this hooked up into my main line.

So it's just a tube, a T-adapter, and I'm doing these two containers.

So I've got the T-adapters so that I can do both containers off of one line.

All we gotta do is plug in the line here and just make sure you get it all the way in so that you don't have any leaks.

And then I can just hook up my emitter.

Same thing: Just get it all the way in so that you don't have any leaks.

One more.

And we are done.

These heads are designed so that you can adjust your water by just simply twisting it.

So if you need less water in the area, just twist it down a little more to go up.

Then we just place it in our containers.

And we can be creative and hide the tubing later up under the mulch that's running behind or anything like that.

And then your system will be set.

I hope that everyone would give a drip irrigation system a try.

This will definitely save you water by putting water right at the roots of the plants where it need to be lessening evaporation.

And it will save you time because you're not standing there with a water hose having to water all of your containers.

And you can even hook it up to a timer so that you don't have to worry about it all.

Just set your timer and you're done.

Happy gardening.

>>And Serome is right now with our team on Facebook, there to answer your questions.

So please send them in or via our website.

We enjoy hearing from you, but here in the studio we have Randy Battle to start our conversation.

So welcome, Randy.

>>Thank you so much for having me.

I'm so glad to be here.

>>And we're glad to have you.

So what's some of our first questions?

>>Okay, one of the questions we have is from Eric in Virginia Beach and he wants to know, "What is an inexpensive mulch to cut down on weeding in our school gardens?"

>>What do you think, Blair?

>>You know, if you're going really inexpensive cardboard and newspaper can help, and then if you wanna make it look nice you can put those wood chips on top.

>>Oh, okay.

>>Wood chips are good.

Sometimes you can get 'em from local arborists.

>>Right.

>>And even sometimes local landfills, you know, have available the chips from, you know, the brush people bring in.

>>Absolutely.

Yeah.

>>So I think that's a great question.

And, yes, it's important to mulch.

>>Mm, hm.

>>Absolutely.

>>Yes.

>>So let's move on to, they didn't send in a name, but we have, "Do rain barrels attract mosquitoes, and how do I stop that from happening?"

>>So there are some products that will prevent the mosquitoes from reproducing in your rain barrels that you can use, or putting, like, really fine mesh on top can help.

Do you agree, Peggy?

>>Well, yeah, I think so.

Have you- >>I like that mesh idea.

I do that, as well.

>>Mm, hm.

>>Mm, hm.

>>Because it's so important to protect it from mosquitoes.

>>Absolutely.

>>But if the screen moves a little, you can get those dunks.

>>Yeah.

>>From your local hardware store, or local garden center, and put those in.

'Cause it's just, bacillus thuringiensis.

>>That's a great idea.

>>And that will take care of the larvae, as well.

But, but my question is how long should the water be in the rain barrel?

>>So you should be using your water and having it drained regularly, yes.

So hopefully you have a plan, would you agree?

>>Right.

Yeah, absolutely.

If you're gonna collect it, make sure you're gonna use it.

That's my goal.

If I'm gonna collect it, I'm gonna use it as quickly as possible to avoid mosquitoes and also to feed my plants.

>>Yeah, so usually within the week, or two weeks, or- >>I'd say about within two weeks, I try to at least use it.

>>Sounds good.

>>Yeah.

And collect only what you need.

>>Mm, hm.

>>Yeah.

>>You know, don't overcollect because the mosquitoes will come out.

>>Oh, yes.

Particularly here in Virginia.

>>Yes.

(Peggy laughs) >>Specifically here in Virginia.

So let's see what we have here.

We have question for you.

"How large of a project do I need to have for VCAP assistance?"

>>So the practices are sized based on the amount of water that's coming into them.

So we, the district staff will walk you through that process of how big it should be.

They're all engineered to that site.

And sometimes you can link them together, have multiple practices that are treating an issue.

So, it just depends on the site, really.

>>Okay.

And how do they reach out to VCAP?

>>Yes.

So you'll wanna contact your district staff.

And the localities are served by different districts.

So that's all on our website.

You can find the specific district that you want to contact and schedule that site visit.

>>And is that vcap.com, .org, or?

>>Oh, so it's vaswcd.org.

>>Okay.

>>Slash VCAP.

So, I work for the Association of Soil and Water Conservation Districts.

It's a mouthful, but the website is short.

And again, VCAP, if you Google it, is what it'll come up.

>>Okay.

I'm glad you had to say that.

(all laugh) Do we have time for more questions?

>>Keep on going.

>>All righty.

All right, what is the best method to work soil amendments into existing compacted clay soil?

>>So you can use a tiller, and if you don't have a tiller, you can rent tillers, as well.

And I, but I was thinking earlier, if you work at a school and you've got a lot of kids with tiny hands, it's not to say you couldn't do it by hand, it would just take a while.

>>Right, right.

And what do you recommend mixing in with that compacted clay soil?

>>Yes, so compost is what we recommend first.

>>Okay.

>>If you really like a retention mix, or have really compacted soil, or if you're making a really big bioretention basin, you can purchase that retention mix, or you can mix it just like I did earlier.

>>Awesome, awesome.

>>I know that bioretention mix is not inexpensive, but it's also very effective and for big applications, it really is a smart way to go.

But another way to soften and mix that soil in is to basically, if you have time to plan in advance and to put the amendments on top of the soil and let them work in over a period of, you know, six months.

>>Right.

>>And that softens the soil, so you can till it in better.

>>Yeah.

>>And that's if you have the time.

I know some people plan way ahead.

>>Uh, huh, preplanning.

It's key.

>>It's the key, yes.

>>Yeah.

(Randy giggles) >>So are we moving on?

>>Yes.

>>Okay.

Sue says, "I have many hydrangeas and only one has bloomed.

The others, nothing.

Is this due to the late frost and freeze that we had this past spring?"

>>It certainly is.

(all laugh) Unfortunately, I don't have one blossom on any of my hydrangeas at home.

And it's due to that late freeze.

You know, the buds are formed the year before on our blue, or I'll say hydrangea macrophyllas, and then if we have a cold winter, or a late freeze, where that sap starts to get up to those buds and they start to swell and then the temperature drops, it's gone.

I have beautiful green growth.

Absolutely lovely, but not one flower.

So ... >>Wow.

>>Everyone's in good company this year.

>>The weather was very tricky this year here.

>>Oh, it was very tricky.

>>Very tricky.

Things are starting a little slower in my garden this year, so.

But they're starting to pick up, so that's a good thing.

>>Well, the soil temperature stayed cool for so much longer, so ... >>Yes.

>>We have one minute left, so ... >>One minute left?

Let's see.

Here we go.

"Is rainwater collected from the rooftop safe to use on all plants?"

>>So it should be safe to use unless you were in some place had something going on in the roof.

Do you wanna add anything, Peggy?

>>Well, I like to use the rain off of our rooftops, but I use 'em on my ornamentals.

I don't use it on the vegetable garden.

>>That's fair enough.

>>I use naturally collected rainwater on the vegetable gardens.

>>Right.

>>Just because it's my food and I'm being, you know, a little cautious in that area.

>>Absolutely, absolutely.

>>And the rainwater you collect, Randy, what's?

>>Well, I do use some of my roof water, but like you said, I like to use it on my flowers and green type of leafy things, but I try to collect it in a basin or barrel.

>>Yeah.

So it's a little separate.

>>Yeah.

Separate from my food.

>>Okay.

Well that's about all the time we have right now.

>>Okay.

>>But we're looking forward to answering more of your questions later in this show.

And thanks for being with us tonight, Blair, we really appreciate you explaining us about the VCAP program, as well as rain gardens.

Next up is Dr. Robin Puffinbarker.

She visited Hone Quarry Dam in Rockingham County to learn more about the important role that dams play in controlling runoff and preventing flash floods.

>>This flat part that we're walking on is known as the bench or the stability berm.

It's designed to help minimize erosion and break the slope into two segments.

>>And is that when we're actually having a flooding event when this would be much more full?

>>If you notice behind me you got the principle spillway pipe there.

And in the event that the water's full to that level, and maybe it maintains there for a little while, this bench is about the same level.

So this acts like a wave berm just like down below here so that the water, like with the wind blowing it, like, it won't cause erosion.

It can dissipate the energy out of the water up against this next section or height of the dam there.

>>So Megen, tell us about where we are today.

>>Well, we're at the Hone Quarry Dam here in Rockingham, Virginia.

This dam is actually located on Forest Service land but the local soil and water conservation district is the owner and operator of this dam.

>>So tell me a little bit more about soil and water conservation districts.

>>So there are actually 47 soil and water districts in Virginia.

Of those 47 soil and water districts 12 of them are dam owners.

Soil and water districts are political subdivisions of the state and these 12 dam owners own 104 soil and water district dams all across the state.

>>And Corey, how do you interface with the soil and water conservation districts?

>>So I work for the Natural Resources Conservation Service and our predecessor agency, the Soil Conservation Service, built most of these dams.

Started in the late forties up through the early or late nineties.

And so we help provide... Work with local partner, in this case the Shenandoah Valley Soil & Water Conservation District.

And they were the partner of the dam and we provided the funding.

And so we have an operation and maintenance agreement with the partners that have the dams for them to operate them for anywhere from 50 to a hundred years.

In this case at Hone Quarry, it's a hundred years.

So we oversee to make sure that the dam's being maintained according to that operation and maintenance agreement.

>>Yes, I remember seeing some really dramatic pictures from the archives of Bridgewater College and Rockingham Historical District showing devastating floods, I think in the 1940s.

So can you talk about the history of flooding and how an earthworks dam like this would be built and engineered to try to help control those kinds of problems?

>>So landowners downstream recognized flooding as a problem and the federal government came in, Soil Conservation Service, and designed many...

Right Cory, many?

>>Yes.

>>Flood control structures not all of which got actually implemented.

But there were many designed for the purpose of protecting all of those agricultural fields downstream of large watersheds.

>>So can y'all explain what we see here as we're standing on the dam and see this, you know, cute little lake behind it?

>>Well, this area here is known as the embankment.

That of course is the lake.

And that concrete structure out there is commonly referred to as the tower or principle spillway.

And in the bottom of the tower there's a pipe that runs through the embankment and comes out on the other side.

And that's designed to carry the water from the lake from this, the wet side of the embankment, to the outlet on the dry side of the embankment.

Cory, what else can you add?

I'm sure I'm missing something here.

>>So in addition to the embankment and the principal spillway we also have what we call an auxiliary spillway or emergency spillway.

That's over here on the hill behind us.

And so in the event of a heavy rainfall event the principal spillway's taken all it can, the water continues to fill up, the water will actually then start overflowing out of the emergency spillway and going down to the stream down below the dam.

That's usually in a really severe storm event.

This dam was designed for a hundred year flood event, to try to store that.

>>And it would take lots and lots of water.

>>Yes.

>>Perhaps even days and saturated soil conditions for this dam to fill up.

But that's what it's designed to do.

It's just designed to fill up, flow out, and activate the spillway if needed.

>>Basically, slowly release the water, hold and store it.

And many landowners downstream don't see flash flooding events anymore because this dam and others in the area are holding back heavy rainfalls.

>>When has maybe the emergency spillway actually been activated since this dam was built, I think you said in 1968?

>>Yes, this dam was built in 1968, and to my knowledge, it's operated...

I know for sure, in 1985, in the November of 1985 flood event, it activated.

And then maybe, possibly, once or twice in 1996.

But in 1985, it did operate the emergency spillway, and it did cause some damage at the outlet where it goes back into the stream, and they had to come back in early 1986 to repair that.

>>And that's part of the operation and maintenance that the soil and water district, as a sponsor or the owner of the dams, that's part of what we're here to do.

So you can see this dam's been mowed.

And that's one of our responsibilities is to maintain adequate vegetation.

And we do that through mowing.

Keep down all the trees and any woody vegetation from becoming established on the dam.

And as a dam owner, we're responsible for ensuring any debris that comes in on the face of the dam during flooding conditions.

If there's areas that are destroyed or damaged or eaten out by the erosive water, we're required to come back and fix those and address those so that the dam is sound and ready to function again should it need to.

>>So why would you be worried about trees on the actual embankment?

And I think we were also talking about groundhogs maybe being a problem.

>>Yeah, so you don't want trees growing on the dam because, for several reasons, but one of the primary reasons on the dam, when that tree grows it has roots, and the roots go down into the dam.

And when that tree dies or if it falls over...

If it falls over it can pull up big chunks of soil, which can expose the the fill of the dam, which can cause erosion.

But more importantly, when that tree dies or falls over, the roots remain, and as those roots decay they can leave a pocket that water can infiltrate through.

And over time that water can infiltrate through the dam and can cause a failure.

And at the entrance to the auxiliary spill right here behind me, you don't want trees growing up because during a flood event, should the water get that high, they can hold back debris and cause a mini dam, so to speak.

And when that fails it can cause a release of water that can cause, you know, major damage to the dam and potentially worse flooding downstream.

>>Cory mentioned those channels, and you can imagine what a groundhog's gonna do.

If he has a hole in there, and if he abandons his hole or even if he doesn't abandon his hole, you know, that's a channel for water to infiltrate into the dam.

>>Another thing is in the emergency spillway...

Here in the mountains, we have a lot of cut back into the mountain where they built the spillway.

And so we have shale and sandstone here that can naturally weather and fall into the spillway.

We have to keep that removed.

We don't want water flowing through the spillway to hit that and churn around it because that can cause erosion or digging and it can cause a failure.

>>There's literally hundreds, if not thousands of people downstream of these structures.

And here we have a lot in series.

So, you know, if there was to be a big storm we wanna make sure that we're doing everything we can to protect those downstream landowners, keep them safe.

>>And I think the dams do more than just protect us from flash floods.

So what are some of the other values of having the dams?

>>So one of the biggest things, and this lake here at Hone Quarry is an example, is they provide a great recreational opportunity for folks in the community.

This lake here is stocked with trout, and so people who come and trout fish here.

They can come here to bird watch.

They can come here to go hiking and just hang out.

We often see people laying on the banks of the dam sunning themselves when we're up here doing inspections.

>>Picnicking.

>>Picnicking.

There's a large, old order Mennonite community here in Rockingham County, particularly in the western part.

And a lot of them will come up here for Sunday for picnics and bring their horse and buggies up here just to hang out.

The dams also have a minor component of sediment control.

So they help to hold back and store sediment that's washing from from the watershed above.

And as a matter of fact, when these dams are designed, when they figure the pool size they actually figure some sediment storage into that pool.

>>Now, and I don't think Hone Quarry acts in this capacity, but don't some of our dams that are used for flood control also provide water sources for localities?

>>Absolutely.

Here in Rockingham we have Switzer Dam.

That is owned and operated by the city of Harrisonburg.

And it was built as flood control but also water storage for the city of Harrisonburg.

And what they actually do there...

They don't actually take water directly from the lake.

They do it more indirectly.

They release water downstream in the dry river and then they have an intake further downstream that collects water and takes it to the city.

>>Wow.

Well, thank you so much for this time and all this great information about flood control in Virginia.

This is just an incredible thing to see and learn about.

>>What a scenic view from the top of the dam wall, these structures do important work to keep downstream residents safe and the recreational opportunities are a great added benefit.

Now I'm joined by Matt Lyons, State Conservation Engineer at the Natural Resources Conservation Service to talk more about large scale water management methods.

But before we begin I wanna remind you to send in your gardening questions through our website vpm.org/vhg.

Well, Matt, this is very interesting because when we think about dams, we morally or less think about the lake that they're holding back the water, but you as an engineer of dams, think of the much bigger picture.

So what do you have here to help us learn and understand, I'll say the process of designing a dam and all of that is taken into consideration within that watershed?

>>Yeah.

What I think I'll do today is we can talk about really how we ended up with a dam such as Hone Quarry- >>Okay.

>>We'll start talking about the big picture I guess, the Natural Resources Conservation Service.

>>Yes.

>>The national efforts down to Virginia and ultimately how we really got down to the process of putting Hone Quarry in, because the story of Hone Quarry is gonna be the, basically the same story for the other 12,000 structures that NRCS has assisted local sponsors with, over the past 75 years.

>>And those 12,000 are nationwide not just in Virginia?

Yes- >>They are nationwide.

Yes.

In Virginia, we've assisted with 150.

Since about 1954- >>That's amazing.

Yeah.

I understand there's only one natural lake in Virginia.

>>Yeah.

I believe it's Mountain Lake.

>>Yeah.

Well exciting.

The rest are all from the dams.

Well, tell us about, you know how do you go about determining where a dam is?

Where do you start?

>>Well, where you're gonna start is really with an analysis of the watershed and the problems that you have there.

And you're gonna try and find the best location I guess, to solve the problem.

And that involves a pretty detailed planning process.

>>And the problem is flooding further downstream having erratic water flows, things like that?

>>Yes.

>>Okay.

So we've got a map with pretty colors >>Yeah.

So what we've got here is a map that shows really what we're calling the major watersheds in Virginia.

You know, things, most people are readily familiar with the James River across the middle of the state.

That's probably the biggest major watershed in the state.

And what we're gonna focus in on today for the Hone Quarry project is the Potomac River Watershed.

>>And that's in pink there- >>And that's in this color.

>>Yeah.

>>In pink, up across here.

So really just to start at the beginning the small watershed program in NRCS is set up to assist local sponsors with financial and technical assistance to solve their local agriculture related flooding issues sedimentation issues, and water supply issues.

>>Which is so important for our farmers.

>>And so really the story with Hone Quarry started in 1936 when the department was authorized to some planning studies and quite a few major watersheds across the country to identify the flooding issues.

>>Interesting.

>>And so that process got started and there were a lot of studies that were done throughout the time- >>Yes.

>>And looking at the Potomac River, they developed a plan for fixing some of the identified problems.

>>Okay.

So what's our next step here?

>>So then the next step is beginning in 1944, Public Law 534 actually authorized the doing some work to actually solve the problems that were identified in the plan.

And so part of that process was locally identified problems in Rockingham and Augusta County with the Lower North River Watershed.

>>So where is this area?

Give it to me by city.

>>Harrisonburg.

>>Okay.

>>It's Harrisonburg pretty much borders it on the west end.

And it extends somewhat over into little bit of Augusta County there but that's really where it's centered around.

>>Okay.

>>And the local sponsors of this project requested assistance from the Soil Conservation Service in the early sixties and the local sponsors, as you saw in the videos the Shenandoah Valley Soil and Water Conservation District.

>>Okay.

So, and from there, it went to a group came in and started studying the site.

And what did they determine?

>>Well, they went through a rather detailed planning process developed a watershed work plan where they documented the problem.

>>The flooding issues that were there, they identified where the major issues were.

This document, the planning document would've identified what the potential alternatives were, the solutions, the economics behind it.

And ultimately what came out of the planning process in 1963 was a recommendation to construct 15 watershed dams in this watershed.

>>Oh my, that's a lot.

>>That was the original plan to solve everything.

>>That's amazing.

>>And so I guess the- >>Next step.

>>The next step would've been after the sixties was to get into the actual implementation and design of these projects which brings us down to the actual Hone Quarry watershed.

>>So what is a watershed?

I mean, we're looking at a map with a lot of colors and ridges and shades and you know, such, so >>So really what a, the simple definition of a watershed is it's a geographic area in which every drop of precipitation that falls is gonna go to a common waterway.

>>Okay.

>>And everything's gonna travel from the vertex of the V down to the large opening.

>>Yes.

>>And so water does flow downhill.

>>It does.

>>Which makes things relatively easy as you start looking at this, but the overall watershed for the Hone Quarry dam I think is somewhere around 5,000 acres.

>>Oh my.

>>You compare that to the overall Lower North River Watershed at about 200,000 acres.

>>Good gracious.

>>So you're controlling a small portion of it, but you can have a significant impact.

>>It's a cute little dam, huh?

Yes.

But the big impact that it has is to control the flow and to protect folks downstream.

>>Yes.

What it really, what a dam does, what a flood control dam does is it's gonna store the water and let it out at a slower rate over a period of days.

>>Fantastic >>By doing that you can cut the peak flow downstream.

>>You can control it.

So let's see what our next step is.

So the dam itself is constructed.

You've done your calculations.

You've determined the highest size of the dam.

And we've got about one minute left to talk further about the dam.

Like how many gallons or how many acres is needed to create a larger dam?

How do you size it?

>>Well, the size is all dependent on how tall you can make the dam and how much volume you need to store.

So there's a lot of computations that are gonna go into this, but typically, as you're looking at citing this you're gonna want it in a narrow part of the valley.

You want to really try to get as much water storage as you can with as small of a structure, as you can.

>>Briefly.

Can you very briefly explain to us how a dam operates?

Like, what is this structure right here?

>>That's gonna be the principle spillway.

That's gonna set the water elevation and allow the base flow to travel through the dam and the principle spillway pipe.

>>So my understanding, correct me if I'm wrong is if this is our principle spillway in case the dam water goes high.

It's lower than the actual height of the dam wall.

And so the pipe goes through that dam but then what's this spillway over here?

>>The auxiliary spillway is to, it's a bypass for higher flows, higher volumes of water.

So it's the water safely flows around the dam and doesn't flow over your embankment and potentially damage the embankment.

>>Well, that's great.

Dam's not only protect downstream, but to wrap it up they're also recreational components in a community too.

Correct?

>>Very much so.

Everybody likes a water feature, I guess.

>>Yes- >>They're very popular.

>>It's fun to go fishing in or just walk around.

>>Yes.

>>So dams serve many purposes and I thank you for sharing the explanation of how they're determined, where they're determined and just a little bit about their function.

So thank you, Matt, for being with us.

>>Thank you for having me.

>>And now we're gonna get ready to answer more of your questions, but first Robin is back again with tips to be water wise in the vegetable garden.

(upbeat music) (water spraying) >>Today we wanna talk about water wise gardening.

We're here at the Bridgewater College community garden to look at how we can save water in our vegetable gardens.

So this garden is large enough that we have to water it with sprinklers.

So one of the things to consider is when would you want to do your watering.

With sprinklers, you really need to think about watering in the morning, because those systems are gonna put water on the leaves of the plant, which could cause fungal growth or mildew.

So you want to water in the morning.

So the plants and the soil have a chance to dry out during the day.

You want to look for your plants to be healthy and well watered as you pick the ones from your garden center.

These have nice strong leaves and everything looks good.

As plants get water stress, the leaves may tend to curl and fall in and wilt down towards the stem of the plant.

And those are plants you wouldn't wanna purchase.

So as I'm planting these, I've prepared my soil and I wanna take my little plant and I wanna make sure while they're still in this cell pack that I'm keeping them well watered so they don't dry out.

These cell packs are infamous for drying out very quickly, even at your home.

So make sure you're checking those at least every day for being well watered.

So now that I've got the plant in the ground, I wanna make sure I press it in nicely.

So the roots are coming in good contact with the soil so they can do their water absorption.

In our flower beds, we are usually used to putting lots of mulch around our flowers to make them look nice and neat.

In the vegetable garden, you can do the same and this will end up helping you save lots of water.

So in this garden, I have lots of wood chips, old leaves, and cut grass.

And I use a combination of those materials as they will compost into the soil to put around my plants to help keep the water in.

If your garden is small enough, you may want to use just hand watering cans like this one.

And then once you've got your plants in the ground, make sure you water them very heavily for those first few days to make sure that root is getting plenty of water so the plant will establish and then grow well.

And then remember to mulch around them to help that water stay in.

Water is such a precious resource, even in our vegetable gardens, we want to be water wise in all our activities.

>>Water is our most important natural resource.

And we are called to do more to conserve it and keep it clean.

Controlling runoff is a great way to get started and it does not always have to take a hundred foot dam to make a difference.

Something as small as a rain barrel at your home, can have a big impact.

And now we have more questions to answer and I'm so excited you're here, Mat, 'cause we've got a lot.

The first one is when were the last dams built in Virginia?

>>Well, the last NRCS assisted flood control dams were completed in, I think it was 2001 in Patrick County in the air at river watershed.

>>Oh, it was a very large one or as in?

>>They, those were much smaller structures.

>>Okay.

Interesting.

I bet you the community there appreciated that.

>>Yes.

>>Yeah.

And another one is, what's the difference between water infiltration and water percolation?

>>I'm not sure.

>>I'm not either.

>>The terms are relatively similar.

>>I was thinking the same thing.

>>Infiltration versus percolation.

>>Hmm.

We'll have to get back to that on Facebook.

Okay.

So can existing dams be built taller as storm events have become more severe in the last 50 years?

>>Yes.

There's a variety of methods you can look at.

You can simply raise 'em with earth fill.

You can use parapet walls.

There there's a variety of engineering methods that you can look at to accomplish that >>Does that then have to adjust the spillway on the side, the emergency spillway.

>>Potentially could.

>>Yeah >>It's you're gonna have to look at everything.

Basically.

When you start talking about raising the height of the dam.

>>Yeah.

Raise the tower, raise everything.

Wow.

That's not an easy process.

>>Potentially.

No.

>>Yes.

(laughs) I was thinking of the sand dams I built as a kid at the beach, you know?

(laughs) >>Right, right, right.

Yeah.

>>More and more.

(laughs) It's a lot more complicated than running down and getting more sand.

(laughs) >>Absolutely.

(laughs) >>What happens to, come on, the silt that is collected there?

How do you remove the silt in the base of a dam?

'Cause, you know, the dam is constructed is that spillway is meant to collect the silt over a long period of time.

But when that builds up, what are the steps to, I'll say refresh the dam, clean it out.

>>Yeah.

If you wanted to restore the sediment pool to open water, you could drain the water that's in it.

And go in with conventional equipment and excavate and haul it out in trucks.

There's, depending on the quality and consistency of the sediment, you've got the option of maybe moving in hydraulically.

>>Interesting.

>>Where you basically mix it into a slurry and you can pump it somewhere.

But it's doable.

It can be around the pricey.

>>But is it a way to refresh a dam?

I mean, does it these dams again.

>>Potentially.

Yes.

>>Yeah.

>>Yes.

You can look at if you need to gain additional sediment storage, you're gonna have to remove what's in there.

>>Yeah.

Interesting.

Well, I was just wondering if a water source dries up does it, you know, what do you do at the dam?

If there's no more water?

>>Well, most dams are fed by potentially a couple different sources.

Some of 'em may be spring fed primarily but they all have some sort of a watershed area that's gonna drain into 'em.

So you're gonna have some level of precipitation coming in.

But it could, if you're primarily depending on a spring flow to keep your water levels where they're at, you may not have sufficient watershed area.

>>It's interesting.

>>To generate the runoff.

>>And if it does dry up, does that damage the dam?

>>No, it should still function.

Particularly if you're talking about flood control.

'Cause really you're looking about just detaining a volume of water behind it.

>>Interesting.

I'm wondering, you know, how long does a dam last typically?

>>Good question.

>>Well, if you're looking at an NRCS assisted flood control dam, one of the things, among many, that we do is we're gonna evaluate the estimated sediment life.

You can run some calculations and determine your estimated sediment yield.

Again, it's all about storing a volume.

And so you, you work that into the height of your riser or the lake level and that's how you determine your sediment volume.

>>Interesting.

>>And what causes dam failure?

>>Well, there can be a variety of causes for dam failure.

You can have piping through the embankment, you know, where the water actually leaks through and erodes material out.

Or, I guess, a more common cause is overtopping of the embankment.

Where water is flowing over the top of it, causing erosion and causing an ultimate failure of the embankment.

But there's a wide variety of potential causes with that.

>>Interesting.

We have a question here about, are snow melt runoffs as big as rainstorm runoffs?

And I was just wondering, we were talking about rain barrel earlier.

>>Right.

>>And in our roofs.

And I know we can't compare the roof of the rain water that you collect.

But I just wanted to ask Randy, you know, when we have a big snow event, does your rain barrel fill up as much as when it melts versus a dam?

So.

>>Well actually when we get snow, it does fill up.

But I think the rain water is, fills it up quicker than the snow water.

Because once the snow starts to melt, it goes down.

>>Okay.

>>So yeah, I think the rain water fills it up quicker.

>>Okay.

>>Than the snow.

>>Well then, the dam, Mat, how about snow versus rain in a dam?

You know, does snow melt?

>>Yeah.

Well typically with snow, it's not, there's usually several inches to an inch, multiple inches of snow required, to make one inch of runoff.

So it does have an impact.

It definitely has an impact and something you want to take into account during your design calculations.

>>So when we get a big, huge snow, you're sitting there going, we're fine.

>>Yeah.

(laughs) >>But when we get a very large rain, you're concerned.

>>Yes.

>>Yes.

Okay.

Well, I wanna thank you, Mat.

We're about outta time and we do appreciate you being with us.

And we also appreciate all the work of the agencies like the Natural Resource Conservation Service and the Soil and Water Conservation Districts are doing.

I mean, it's just amazing the amount of work that you're doing and the, I'll say the lives you're saving and the communities you're protecting.

So thank you.

>>Thank you.

>>I also wanna remind everybody to visit the Virginia HomeGrown Facebook page.

We always enjoy hearing from you there and if you're not watching on Facebook already, then please go ahead and switch over right after the show to catch Jen Naylor's latest eating fresh segment, on sesame leaves.

I wanna thank you, Blair and Mat, once again for being with us, it's been a great show.

But also thank Randy and Robin and Cerone for all your contributions tonight.

And I thank you for watching.

Next month we'll be talking about agriculture and exploring programs that make farming more inclusive.

I look forward to being with you then.

And remember gardening is for everyone.

We are all growing and learning together.

Happy gardening.

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