Shading of the river banks will go a long way toward preserving moisture. Tall trees planted at each outfall garden would cast some shade and provide the beavers with wood.
Dale Hodgins wrote: This will also prevent mosquito population explosions during times when there are big pools but no flow.
John Elliott wrote:Not to worry about mosquitoes in the desert, Dale. As a kid, I would go fishing at lakes on the various golf courses in the area (that was the only water around, and they stocked them) and didn't see a mosquito or get bit once. Even along the Colorado river, where there is a year-round flow of water, there is not much of a mosquito problem. Something about humidity in the single digits makes it so that any mosquito flying around quickly turns into a sun-dried mosquito.
John Elliott wrote:Jennifer, I'm surprised at what you said about the canals being sealed. About 30 years ago, I remember living near Central and Camelback and once a week there would be irrigation water from the canal to keep the yards green. At that time, they were appreciative of what the Tohono O'odham had left and were still glad to use it. I suppose as urban sprawl covered an area far in excess of what the canals could support, they became, like you say, a dumping ground and an eyesore.
John Elliott wrote:And you are right about stormwaters not being well handled. Even in Las Vegas, where they have designed in 40 acre impounds, they forgot one minor detail: how to get the stormwater to flow INTO the impound. One time I was stuck at a flooded intersection, with water coursing along the street, looking at the inadequately sized culvert trying to divert some water into the impound, but only to be blocked by debris that was covering it.
John Elliott wrote:Is there any group there in Phoenix, government or NGO, that is giving away (or selling at very reduced cost) trees like palo verde and desert ironwood? They are the kind that would do well planted even in the floodplain of the Salt river. And it's so easy to start them, you can use any sort of plastic pot and all they need for the first three years or so is some TLC in the way of regular watering. Once they are about 3 years old, you can plant them out and they will survive, because that is the climate they are adapted to.
allen lumley wrote:Jennifer and Dale : O.K., I originally came to Permies to talk about Rocket Mass Heaters RMHs, and now I have less and less time in my life, and more and more Good People to Help !
So, for the rest of us, who wants to define :
Slow and spread, recharge sites, Climate/environment adapted I Think thats obvious, but, to too many people grey water is what is left after you wash your face, and needs to be quickly drained, out of sight, out of mind (Or, have no clue at all )! Is it insensitive to point out how fast peoples eyes glaze over, when you mention Sewage Treatment, and if it's done right there shouldn't be an effluent,Right? That Is what we have the City Fathers for, Right? and what is a flocculate? Storm Sewer Dump Zones, whats the punch line, should the kids leave the room? infiltration PITS? N.I.M.B.Y.!!, Sponge parks, don't my kids watch too much of that on T.V. now !? A rise in the water table, I'm from back East -but I Know thats Bad, Right?
Jennifer Wadsworth wrote:OK - this post is about a dream I have. I have it all the time. I want to see the Salt River, which runs through metro Phoenix Arizona to run again. In my lifetime (say in 20 yrs).
Dale Hodgins wrote:The rather level nature of urban lots that slope gently toward the street, tends to prevent on site percolation of rainfall. If every lot within 5 miles of the river were required to have a dish shaped rain garden large enough to handle all of the roof and other hard surface runoff, the entire city and the river would benefit.
Dale Hodgins wrote:I find it very strange that areas with much lower rainfall, go to great lengths to quickly flush every drop of moisture to the river, lake or ocean, when the place to store that water is in the ground. Every park in dry cities like yours, should contain percolation ponds, rain gardens or whatever name sells. Some of this water will leak into the river, but it will do it slowly and not contribute to floods. The land surrounding rain gardens are a natural spot to grow trees that might not naturally survive in a desert environment.
Dale Hodgins wrote:The question is not "how do we fix the river" but "how do we get the city on side to take these steps which will absolutely improve the river and the whole region's ability to gather and retain soil moisture". If most rain that falls on your city were absorbed into the soil, the river would come back in some form on it's own. With the addition of beavers, who are helped along by some man made earth works, this could happen quickly. As John mentioned, a couple El Nino years. If the landscape were sculpted to take advantage of the next deluge, decades worth of depletion could be reversed.
Miles Flansburg wrote:Key line plowing is another tool for getting rain water into the soil.
Brett Andrzejewski wrote:I say do everything to try and achieve your dream. You and the area of Phoenix have everything to gain and nothing to lose. Be patient with yourself and do little steps to make it happen.
Jennifer Wadsworth wrote:Yep - it's a damn tall order.
And I wasn't necessarily thinking of going too far up upstream in the watershed but slowing and soaking water near the bottom of the watershed.
Where I live in Phoenix is about 2 miles from the Salt River (bed). If a large number of micro soakage areas (in people's yards - with infiltration pits, or along streetscapes with green infrastructure or "sponge parks") were implemented, my thinking (only a theory as I am no hydrologist) is that:
--we would first start rehydrating the soil in the areas immediately upstream of the river bed
--eventually (years later, surely) there would be a rise in the water table and low spots in the river bed would start to form ephemeral ponds
--years after that, perhaps there would be enough moisture to have an area that stays wet all year 'round.
All areas of the watershed need work. The thing is, you can work on them separately and still obtain a better yield that what we get by simply letting our extreme rain events cause dangerous flooding and dump themselves into the Salt River, taking out bridges in some instances and further eroding soils. "Slow and sink" perhaps combined with some "leaky dams" (gabions) and other ideas could build up the water table again.
Honestly - I don't think we have a choice NOT to do this. Tucson is in the process of trialing it right now.
As an aside - a similar methodology is being used to soak storm water into the water table and divert it from going down overtaxed sewage drains in Brooklyn which then allows raw sewage to overflow into streets. (National Geographic, Nov 2013 p. 19-20)