Thursday, March 29, 2007

Government Rain Collection

The Trib has a front page story titled: Rivers Thirst For Elusive Rainfall

"Tampa, which relies on the river for its fresh water, is reaching beyond the river to supplement its supply with 30 million gallons purchased daily from Tampa Bay Water, the region's water utility.

The duration of the current dry spell is reviving memories of the Florida drought that lasted from 1998 until summer 2001. It drained water supplies, ignited wildfires and parched lawns across suburbia."

For years we have been under water conservation rules, in regards to lawn and plant irrigation. The Hillsborough County Extension Service pushes rain barrels to help deal with the issue.

"Florida receives an average 52 inches of rainfall a year. Most of that water flows off our roofs onto lawns and driveways, picking up fertilizers, pesticides and other pollutants that eventually find their way to our lakes, rivers and streams, contributing to non-point source pollution. Rain barrels are a convenient and efficient way to collect some of that water. You'll not only help to reduce the storm water runoff from your yard, but you'll have a free source of chemical-free water to use for irrigating your landscape!"

Other people use rain water to aid in flushing of toilets. Learning Gate Community Schoool, in Lutz is constructing a new building, that will be green in nature. Designed to reduce energy costs, it will uses collected rain water to flush toilets.

So what about our government buildings? How much water collection space (roof space) do we have on those buildings and on parking garages. Why does not city/county and Florida state government buildings being using rainwater for irrigation or toilet flushing. At a recent meeting of the Lutz Civic Association, a representative for the School Board was disucssing new builkdings being built on the severla area school. not a single one had any method for rain water collection. At the same meetign a presentation was made by the Learning Gate School, where they touted their rain water collection.

The old Hillsborough County Courthouse has a cistern. Of course whether it is being used now is another matter.

A study should be doen to see if it would be cost effective to install such system in new construction and retrofit in existing government buildings.


Cookie Puss said...

This is the territory of people with more knowledge of this subject than me, but I'm scratching my head over this.
It seems to me that by collecting rain and diverting it to lawn watering and toilet flushing, one is actually hindering the recharging of the aquifer. Obviously rivers aren't fed solely by the rain that falls directly over them. Say we take x amount of square footage for a home or other building, collect the rain that would eventually soak into the ground or find it's way to the river via runoff, and then water our lawns with it. What would normally soak into the ground after evaporation and plant absorbtion is actually decreased by the collection, and the dispersion in lesser quantities than nature intended. Lesser quantity = more evaporation + more plant absorption.
So, in trying to be green, are we actually achieving quite the opposite? Someone please enlighten me if I'm wrong.

IFly said...

Right now, unless you're in a development with reclaimed water, you flush your toilets and water your lawns with potable water taken either from the river or the aquifer and treated. I don't believe we get deep aquifer recharge from surface fall in the metropolitan area, and anything downstream from the dam quickly ends up in the river below the drawdown point and shortly the bay. Treated wastewater, at least in East Hillsborough, ends up in the bay as well, via the bypass canal I believe. Essentially, any water you don't use from the drinking water supply is water that doesn't have to be extracted from the river or aquifer and undergo costly treatment. Particularly for watering lawns all the collected rainwater would eventually go the same place it would naturally(well as natural as hitting a roof and running down a gutter before going in the ground or stormwater system) it's just delayed by storing it in a rain barrel. It's certainly more complicated than that, but I think that's the gist of it.

Jeff said...

The water cycle includes the aquifer (which is actually a big underground river flowing south to the everglades). Each part of the hyrdologic path has storage points (rivers, lakes, acquifer, plants) which allow for a certain amount of "flexibility". Water that is put on your lawn will eventually end up back in the cycle, part evaporates and part soaks back into the acquifer.

New construction now requires the use of retention ponds to replace this recharging that asphalt stops (this is done mostly to aleviate storm flow).

To answer your question more directly, the water will still be part of the cycle. If it is used in your toilet, it will go to the wastewater treatment plant to be treated and returned to the ocean, where it will evaporate. If it is sprinkled on your lawn, part will evaporate, so will be used up in photosynthesis (which absorbs CO2).

Even recharging the aquifer below the dam is good because below ground, it's all connected. Recharge here affects the surface there. Right now, we're in a battle with the Gulf to keep saltwater out of our aquifers.

The hardest thing to fathom about people proposing the use of cisterns is the history we have with them. Cisterns were a large source of disease and mosquitos in times past. We actually removed cisterns for health reasons. Also the amounts needed to water your lawn would mean large amounts of storage which would have to kept clean. Some people may be able to manage this but I shudder to think mismanagement would bring.

Anonymous said...

I would like a cistern of some sort. There... I said it. :-)

I have a pool and during the dry months I have to pour potable water into it. During the wet months I pump it out. Wouldn't it be great if I had some storage under my deck that could collect water during wet months and, once filtered, refill my pool during the dry months?

As an aside, if you have a tar roof (like asphalt shingles) and you collect rain water from it, this water has oil in it. Use accordingly. Great for your lawn, not so great for your orchids, dog, or children.

Jeff said...

Well, I can design one for you.

I estimate that you can get 50 gals a day possibly from a cistern. You'd need one 2000 gal at a min, 4000 is best. 2000 gallons is a 6 foot diameter tank 10 feet high. 4000 is an 8 ft diameter tank 11 feet high. You'll have to pipe all of your gutters to one spot, install a filtering system, a pump, a chlorination system, valving, piping, control unit. I can build you one for just under 8 grand. How 'bout it?

Oh yeah, you'll be saving about 10 bucks a month.


Anonymous said...

Wow! That much water just to buffer my pool?

Imagine how much kitty kibble you could buy for 8 grand...

Anonymous said...

the water that they are talking about is "run-off". Run off water does not end up in the aquifer. Aquifer is recharged through seepage and direct recharging through lakes and swamps. I thought that our water problems were supposed to be solved by the Desalination Plant. What ever happened to that?? I know we spend about $100,000,000 on the project and I don't even think its running yet. Anyone have any knowledge about this???

Anonymous said...

Yeah, I am all for this one. Lets put barrels all thru the ghetto. Just imagine how creative all of our neighbors would be. I would feel real safe letting my kids play outside as my neighbors barrels, aka mosquito farms, grow herds near my back yard.

How about our leaders pursue more viable options such as desalination, etc.

Seminole Heights said...

Exactly, run off is the problem. It Lutz we you have more room for swales, retention ponds and where you already have many swamps and conservation areas, the water running off is not so much a problem. However think of all of the concrete and impervious surfaces downtown. All of that water goes into the stormwater system and into the bay. Not into the aquifer.

How much water could that be? According to the SWIFTMUD

"For a general calculation, you can collect about a half gallon of water per square foot of roof area during a 1-inch rainfall. As an example, a house with a 2,000-
square-foot roof can collect about 1,000 gallons of water (the actual amount of rain that falls on your roof is about 20 percent more, but some is lost to evaporation, runoff and splashing)."

So how much could a 25,000 sf government parking garage collect? How much could several of those collect?

Also, when properly made, Rain Barrels are not mosquito farms.

Anonymous said...

9:58, just about all rain barrels these days come with lids and spigots on the bottom for attaaching a hose. You can make an expandable cistern by daisy-chaining several barrels together with PVC pipe.

As to runoff, you can get around *that* by replacing parking lot blacktop with a more porous surface. Two friends of mine have a business where they sell a very porous paving material made of recycled stuff that wears like iron. They do this demo where they take a little bit of the material (about the size of a hockey puck) and put it under a running faucet. The stream of water goes right through it.

Imagine large stretches of Florida Ave paved with this stuff. No more standing water, eh?

RMT said...

How much water would be saved by not watering lawns?

IFly said...

Runoff is definitely a concern as it carries pollutants directly into sensitive ecosystems with no natural processing by wetlands. With regards to recharge, Tampa is basically sitting on the end of the "pipe" around here for the Floridan aquifer. Recharge isn't the major concern in the bay area as even if Tampa and all it's asphalt and concrete disappeared, the effect on the Floridan would be negligible downstream because effectively there is no downstream from here. The bigger concern from a water conservation perspective is drawdown "upstream." The more we suck from the ground the less head pressure there is where the aquifer meets saltwater so that boundary moves ever further inland. Tampa gets most of it's drinking water from the Hillsborough river not the aquifer(though right now, we're using more and more groundwater from Tampa Bay Water's wellfields). St Pete gets it's water exclusively from Tampa Bay Water which if memory serves is similar to the power grid and pumps water from various local sources, surface, ground and eventually desal(one day maybe?). The basics of the rain barrel, reclaimed water, or cistern-type supplemental system is that you use less potable water(which has to be pumped and treated) and in effect need to suck less water from the ground or the river.

IFly said...

rmt, roughly half our water goes to outdoor uses(washing cars, watering lawns, filling pools) I would bet that the biggest portion of that is for landscaping. That's one of the reasons reclaimed water is a useful conservation tool if it's available(not to mention it in some ways reintroduces at least some level of natural processing of the water in that part of the cycle vice directing it straight down the stormwater system).

Anonymous said...

A properly maintained pool with some impermiable decking around it evaporates less water than the equivalent area of lawn requires to stay green. IOW: pools use less water than lawns.

Anonymous said...

waitaminute waitaminute waitaminute waitaminute waitaminute

We have a stormwater system?

IFly said...

I see what you did there anon@11:52. For the sake of discussion, we have to call it something :-).

Anonymous said...

We even have a stormwater department

Jeff said...

Okay, one at a time.

1) Recharging is important everywhere. It's all connected. The piezometric surface here affects the piezometric surface just upstream from it and so on. And the surficial aquifer affects the ones below it. Ifly, you might be assuming that the Floridian Aquifer flows in the direction of rivers, it doesn't. It flows from high to low levels. A pipe is not the best analogy.

As a result, we are getting more and more salt water intrusion. In fact, one of the arguments in favor of letting more water over the dam is that a high salinity lower Hillsborough river increases this intrusion.

2) Polluted runoff is a problem everywhere, no matter where you are. Runoff from farms carry many problems with them. Asphalt is everywhere. Stormwater is no more polluted here than elsewhere.

3) The Desalination plant was a bill of goods that was sold to an overwrought water board. It was the largest of its kind and received very little cost-benefit analysis. The urge to be first led to the reality of the most expensive. It still isn't working up to speed and they've had to increase the budget over and over. Someone said 100 million, ha! Try twice that. It's expected to produce water about 3 to 4 times as expensive as current technologies, and then there is the question of discharge of heavy salinity into the bay. A lot of people made a lot of money off this project and they continue to. In essence, Tampa was forced to be part of this because we belong to the coop, Tampa Bay Water.

One of the best technologies, is ASR, Aquifer Storage and Recovery. Basically, you store stormwater in large underground aquifers and then redraw it later. It has the benefit of keeping salinity out of the wellfields.

Another technology is called, derisively, Toilet to Tap, where treated sewage/storm is recycled into the drinking water system. . Other places in this country and around the world are moving this direction, not desalination. There was some talk of this in the Mayor's office of using treated sewage to augment flow in the lower hillsborough, but the public rose against it. The funny thing is that it happens now anyway. Where do people think treated sewage from the interior cities goes? It's either injected into the aquifer (whereupon we draw it out later) or it's discharged into surface water where it meanders its way to our reservoirs.

Jeff said...

Also, about rain barrels. Most things when properly made and used are not problems. In the hands of Joe Average, they become problems and health concerns. It's possible to use mosquito traps but it adds an element that has to be cleaned and checked. If come the mosquitos.

I think they could work but it isn't something that I'd trust if it were forced on people. People are free to use them now and they receive very little attention because of their expense and complicaton and who wants a big tank in their yard. It's one of those things that I plan to do when I can find one cheap.

Otherwise, we're already at 1/4 the water usage of the average Florida Resident in this house. Front loading washer, yellow is mellow, etc.

As far as that goes, the city of Tampa is pretty good at 110 gal/cap/day compared to the average south florida resident at 175.

IFly said...

Jeff, my hydrology is a bit dated, but if memory serves, the Floridan here flows basically downhill from the Lakeland area almost due West or very slightly West-Northwest through the Tampa area. I didn't mean to imply that the effect is absent, but it seems rather negligible when discussing the original question. Doesn't recharge of the Floridan in this area really only occur through karst lakes and the exposed limestone areas to the east? Also I thought they actually inject wastewater into the saltwater areas of the aquifer in southern Florida?

Jeff said...

The Floridian isn't homogenous and downhill is a term that is unfortunately used to describe flow. The aquifer is everywhere under our feet, some areas are more affected by surficial bodies than others. It always flows from high potential to low potential and that generally is toward the everglades. However, it can flow in any direction.

Protection of the surficial is mentioned in the reports on MFLs in the Hillsborough. So, the surficial aquifer is important as well and that is recharged everywhere (which in turn will recharge the layers below) not to mention there are still many people attached to the surficial.

Just about any effect at this geologic level is small but over many years becomes very serious.

They inject anything in south Florida. Most of the reverse osmosis plants inject their waste brine. Injection is common everywhere. In some areas, the injection of treated sewage and the potable water withdrawal points are pretty close.

Anonymous said...

Roughly 60% of water usage in the typical residential household ends up in the yard. To reduce your draw on potable water you can simply reduce your lawn and convert to drip.

Mal Carne said...

Related to water conservation but not really on this same topic:
Getting ready to turn my attention to landscaping. Never been a fan of this stuff that passes for grass in most lawns in FL and I'm allergic to my lawnmower (j/k) so I'm looking at xerra scaping. The two key considerations are the conservation factor of using native plants that require less water and well, I'm just kinda lazy about yard work.
Does anyone know of any good resources for finding the proper plants, tips/tricks etc?

Anonymous said...

Congrats on considering xeriscaping. Contrary to popular belief, it doesn't mean a gravel yard, especially here in Florida where we get ample rain to grow lush vegetation.

I'm a huge fan of xeriscaping and have been tinkering with it since 1990. (I used to live in the Mojave Desert)

That said, most of our local nurseries are Home Depot or Lowes. So you can pretty much forget any direct support for xeriscaping from them. They do offer some appropriate plants, but very few. Look for the "Florida Friendly" annuals at Homo Depot.

Our awesome local nursery, Manny's, doesn't have a xeriscape section either. If you know what you want, he *can* get it. So that is one option for the larger plants you can't get at Home Despot.

The only good, solid resource available to us is, sadly, available only twice a year: the USF Plant Sale. The native section sells out *very* early for this reason. You MUST get there opening day at or near opening hour to have any kind of selection.

Having said all that... look at coontie palms (native) and their relatives the cardboard palms. These two cycads don't get the Sago Crud, either. (Sago's are drought tolerant) Most ornamental grasses are good choices and there are a few native ones. Most established palms that we can grow here are drought tolerant. I'm fond of the native cabbage palm, myself, but it's common and people seem to devalue it. (People--it has NO THORNS! Grow a Mexican fan palm, trim it for a few years, and you'll understand.) Palmettos are hard to come by. Don't dig your own as that's a) illegal and b) they don't transplant well.

Also, people often forget that xeriscape does include high-water-use zones. Place these near areas you spend large amounts of time and collect all your high-water plants together in that area. Try to have no more than one each for your front and back yard. (or none, but you'll be happier if you have at least one.) If you can arrange the zone such that it's in the runoff area for gutters, your a/c, etc, so much the better.

My advice is to start by establishing a drip line for your yard and remove any grass that isn't needed for daily activities. (I keep a canine maintenance zone (ahem) and a bit near the curb for people getting out of their cars.)

IFly said...

USF Botanical Garden Calendar

We were at the gardens and plant shop on Saturday, it's a nice little hidden gem here in Tampa. They had some gorgeous orchids in the conservatory. I was hoping to make the Spring festival, but I'll be out of town.

RMT said...

Should we have tighter restrictions on lawn watering (except when reclaimed water is used)? Why do we allow the Deed Restricting of St. Augustine lawns???
re: anon 9:40
seems like an opportunity for nurseries to carry more natives (such as Saw Palmetto).
Thought Joe Redner made some good points re: H-borough River in his letter to the Trib (today's edition)

Anonymous said...


The problem with that is our major source for plants are the chain stores which buy en masse. So we tend to end up with mostly the same plants that'll grow anywhere in the greater SE U.S. region. They won't carry what they cannot sell easily everywhere. In addition (and equally important) is that some natives are difficult to reproduce rapidly/cheaply. Coontie palms are a good example. They grow slowly from seed. Saw Palmetto is another difficult plant to propogate.

Many water-hungry plants can be placed in a xeriscape if you mulch heavily and keep them a bit in the shade. Established evergreens also use less.

Oh... check out, too.

Virginia said...

A great source of information on Florida Friendly Landscaping is the County Extension Office. They offer classes on rain barrels, composting, and landscape design. The link on Home Gardening and Landscaping has some great information. The Master Gardener help desk, 744-5519x7, offers assistance, too.

You can buy native plants at Wilcox Nursery in Largo. Well worth the drive.

I use 2 rain barrels and even without gutters they fill up quickly after a hard rain. Right now, alas, mine are both empty.

The spring plant festival at USF is April 14-15. I'm a volunteer in the plant shop. Stop by and say hello.