Utilizing Perennial Cover crops and contours to collect and save water

 

Integration of water saving techniques to the organic farm without comprising the end production of crops for the CSA was the guiding thought of our idea. Utilizing the plants themselves to better capture water runoff and increase infiltration without reducing crop outputs is the key technique we used.  We decided to utilize a system of contoured ridges to slow water runoff and to facilitate pooling of water to increase available water for infiltration in key crop growth areas.  IN addition the ridges could be utilized to house a water collection system such as a series of tile drains or french drains to collect excess infiltration.

The tops of ridges would be placed into a rotation of perennial productive crops including crops such as strawberries, or flowers for the CSA.  The low ground between ridges would be perennially cropped with a rotating series of low growing cool season cover crops which are photo dependent for growth and utilize minimal root energy storage. This would allow the crops to be grazed for forage or mowed for mulch in the spring thus slowing warm season growth and allowing transplanted crops to out compete the permanent cover crops.  The areas of annual transplanting would rotate yearly to prevent buildup of disease and pest pressure or soil compaction.  Additionally the Cover Crops would help lower evaporation of surface moisture to decrease irrigation needs during the season.    

-Emily Rude

-Jason Parsley

Water/Energy Storage System

The system I looked into for the water aspect of our smartFarm was to combine water storage with a turbine to both store renewable energy created onsite, and to automate the watering process.

The incremental watering process would be done through the use of a level sensors at the watering tanks (halfway down the hill) and a solenoid valve. The desired level of water needed for the storage tanks would be modified by the farm workers to meet the demands of the crop.

Rain water collected from 6,000 sq. ft. roof = 62,200 gallons

Total Storage needed = 468,600 gallons (*assuming 500,000 gallons - roof collection during growing season)

Intermediate watering tank size = 290 gallons (* assuming watering twice daily and half watering demand is located below the tanks)

**See linked spreadsheet for additional calculations

The energy storage side of this system would allow the rainwater collected to be used for more than one purpose. I made a sketch in Google Sketchup (link below) and the approximate height diferential between the upper tank and the lower tank is 15.7m. Here are some results from the spreadsheet I created.

from PE = KE or 1/2 mgh = m*v^2/2 -> 12. 4 m/s = 40.7 ft/s -> 130 gpm in a 4" pipe (*system syzer wheel)

The average house consumes 8,900 kW-hr's per year (1020 W's continuously for a year)

At full flow 130 gpm (4" pipe @ 1 ft/ 100 ft  pipe pressure drop) power produced is equal to 47.6 kW

At 3 gpm flow (3/4" pipe @ 2.5 ft pipe pressure drop) 1.1 kW (typical house consumption)

A full tank would allow for 108 days of power generation @ 3 gpm

Or 2.5 days of peak power generation @ 130 gpm

**My calculations do not loses by the pump and neglected friction, but the ammount of power available even after the loses are accounted for w

The concept shown on this picture is more visually represented in the google sketchup model link located at the end of this text.

http://tinyurl.com/yjotygu  Calculations

http://preview.tinyurl.com/ygc6fpd  Google Sketchup

Human Energy- a Water Experience

If we could use the kinetic energy of people within the building to power the movement of water we would not only save energy that could be going to other systems, but create an awareness of how much water we are using. Using the shock energy from a stepping motion, this idea is that people would essentially pump the water that they need to the outlet required. Rainwater from the roof, as well as that needed from the aquifer would be held in a central tank, which would then filter and pump the water out to the other small water tanks located by the water-facilities in the building. Similar to how you would squirt a water gun, or push down on a thermos-dispenser to get drip coffee, the entire system would work on a system of volumes and pressures within the set spaces. One-way valves would help keep the pressure in the individual holders while energy was being exerted (to keep the water from “backing up” towards the pump), leaving the water only one exit- up through the small water tubes running on the interior of the walls. By exposing the water tubes to the user, inhabitants are not only physically seeing the results of their efforts, but are cognitive of how much water they are using. It is easy to just have the sink running while you are brushing your teeth- but I am sure we would all conserve much more if we saw the water moving towards us while we were pushing down with our foot.

Most of the research for this is still in the conceptual phase, but Gunwook Nam’s “Human Pump” is a cool project to check out. Similarly, it explores the idea of human energy through stepping to bring drinking water up to the inhabitants.

Mackenzie King

Artificial Aquifer

Currently the roads and paths on the farm make up about 5% of the total farm area.  These surfaces are used by tractors and vehicles and consist of dirt roads or bare grass.  While such surfaces do not produce as much runoff as conventional pavement, the runoff coefficients are considerable (0.82 for dirt roads and 0.3 for grass on a steep slope).  If we were to replace these roads and paths with pervious concrete (runoff coefficient of 0.05) with reservoirs below them, we could maintain an artificial aquifer lined with impervious pavement.  We would draw irrigation water from this reservoir, hence reducing our consumption of water from the Grande Ronde Aquifer.  With the current road and path layout of the farm, we would capture approximately 370 gallons of water per year.  The slope of the farm could be utilized to deliver this water through gates and into a drip system to irrigate the crops without the use of pumps.  If we find evaporation of water through the concrete to be a concern, we might either cover the road surface with durable plastic sheeting on sunny days or look into the use of a chemical monolayer on top of the water (below the concrete), if it is organic.

It may be desired to collect additional water for delivery to plants since current water consumption is 500,000 gallons per year.  To meet this need, the concept could be extended to collect water not only on road and path surfaces, but also other areas not occupied by crops.

Christophe Parroco and Jennifer Johnston

Update on Wednesday, October 21, 2009 at 2:54PM by Jennifer Johnston

C (dirt road)	0.82
C (lawn)	0.30
C (pervious concrete)	0.05
Road area	54140.00
Roads as percentage of total farm area	4.97%
Annual Rainfall (inches)	20.00
Annual volume of water on road surfaces (cubic inches)	90233.33
Annual runoff (dirt road, cubic inches)	73991.33
Annual runoff (pervious concrete, cubic inches)	4511.67
Water captured annually (cubic inches)	85721.67
Water captured annually (cubic feet)	49.61
Water captured annually (gallons)	371.06

Farming Water: Techno-Dousing & Semi-Terraces

We would like to reassess the amount of water we can grab from on site. Throughout the entire site just less than 3 million gallons fall annually. About 70% of that falls when we don’t need it (between October and April), and is lost due to runoff and infiltration. We have two applications of “water-farming” that we think might work, but we will need more information to make a decision.To deal with this issue we would like to obtain detailed information about the farm that can help us in our pursuit to “farm” this water. We would like to map the subsurface to find out where the hydraulic gradient runs, and how deep. This can be achieved using a Magnetic Resonance Imager (MRI), which might be available through a professor at the University of Idaho, which would kind of be like Techno-Dousing. A map of the subsurface structure would allow us to make a decision on which application we choose. We would also like to better understand the soil and obtain information on hydraulic conductivity, infiltration rates, and other characteristics. This will not only help us choose an application, but will help us model the farm so we can better understand how water is moving through the soil. The computer model that would be simplest to work with and understand would be WEPP; Water Erosion Prediction Project. With a computer model of water movement in the soil, we can have a pretty good estimate of the amount that can be potentially “farmed”.Our first application would be shallow wells. This will only work if water is collecting under the subsurface in an easily obtainable spot; if the water is pooling 10 feet below the surface at the southern edge of the farm this might be ideal. We might also have to modify this spot to ensure that water stays there, possibly by installing pile walls to trap the water in this location.Our second application would be semi terraces with French drains installed. This option would potentially re orientate the farm along topographic lines, and allow water that collects on the surface and through the substrate to move towards the French drains and be collected centrally through a system of cisterns and finally into a lagoon. This system would not only trap water when it is not needed but would also slow down rain water when it is needed, so we would not get unnecessary run off. Evaporation is a concern with a lagoon, however if we only catch 50% of the water that falls between October and April, we still end up with 1 million gallons, an overwhelming surplus that would mean we could scale back the system in years of heavy precipitation and scale up the system in years of drought. What is still not understood is how necessary this water is to our local watershed. Will we be depriving Paradise Creek of necessary rain-water or will we be just fine? Is this scalable? Would we want such an invasive system? Eric Wegner, Josh Van Wie, Josh Gile

Enhancing Rainwater Collection

   

To increase the amount of rainwater that can be captured, I propose a roof that can increase in surface area.  The “roof” would have two layers.  One would be glass and the other would be photovoltaic panels.  During sunny conditions the photovoltaic panels would be shading the interior space and creating energy.  During rainy conditions the photovoltaic panels would move to aid in rainwater collection.  This would also allow natural light into the interior space because the photovoltaic panels are no longer shading the glass layer.

Jonathan Follett

Rainfall Harvesting

It is estimated that our current plot of land will require 500,000 gallons of water annually to support life on the farm.  In order to reduce the dependency on the aquifer, it would be beneficial if we could design a way to harvest the rainwater that falls on the areas around the farm that do not require it.

My design idea is to cover the walkways and roadways that surround the farm and run through it with a grated system.  Underneath this grating system, there will be a preliminary water containment area.  This area will contain a thin layer of oil.  The purpose of this layer of oil is to reduce the amount of water lost to evaporation.  Since oil has stronger bonds than water, its rate of evaporation is much slower than water.  And since oil is less dense than water, it floats on top of the water.

Separate from the first water containment area, there is a stored water area, connected to the main containment area by a flow control valve.  It is at this stage that any necessary filtration could be taken care of.  By putting the flow control valve at the bottom of the containment area, only the water would be drained out.

Assuming 100% of average rainfall over the grated roadways makes it into the containment area, over 68,000 gallons of water would be harvested.  Realistically, taking into account various losses, it is probably more likely that 70% of the water would be contained, which is still almost 50,000 gallons of water (10% of total farm usage).

            280’ x 10’ + 340’ x 10’ = 6400 ft²  (square footage of roads/paths)

            6400 ft² x 21.2/12 (average rainfall) = 109353 ft³ (volume of water)

                                                                      = 68,224 gallons (volume of water)

            68,224 x 0.70 = 47756 gallons (adjusted volume of water)

The Living Well, or, Utilizing Plant Hydraulic Redistribution in an Agricultural System

Hydraulic Redistribution is a recently discovered phenomenon by which certain plant species are able to  transfer dormant season precipitation (November-March) and summer rainfall deep into the soil profile via tap roots and deep lateral roots. During the dry season, then, when water in the uppermost section of the soil profile dries up, pressure gradients pull stored water up through the tap roots and redistribute it into the upper root system and immediate soil matrix.

One Hydraulic Redistribution study was conducted on Douglas Fir trees in the Gifford Pinchot National Forest in Southern Washington. The study site was a dense forest canopy on a sandy loam soil with an understory of Oregon grape, small hemlock, and Huckleberry, that receives most of its precipitation between October and May. At this site, redistribution began in late July/early August, and was able to replenish nearly 50% of the daily water use at the end of summer. The Douglas Firs in an irrigated trial were able to transport water from the irrigation site to nocturnally replenish soil up to 3 meters away.

While Hydraulic Redistribution is not revolutionary, applying it to agriculture is. The Douglas firs in the study were able to pull up stored precipitation to use for themselves and to be used by the food-producing understory plants. I propose that we utilize Douglas Firs, or a similarly well-suited species with HR capabilities, interplanted with a crop to be harvested as a primary component in our irrigation storage and distribution system.

Other HR species: Helianthus anomalus (Western Sunflower), Artemisia tridentate (Common Sagebrush), Quercus laevis (Turkey Oak), Prosopis velutina (Velvet Sagebrush)

Hydraulic redistribution in a Douglas-fir forest: lessons from system manipulations.

BROOKS, J. RENÉE¹ Brooks.ReneeJ@epa.gov

MEINZER, FREDERICK C.²

WARREN, JEFFERY M.²

DOMEC, JEAN-CHRISTOPHE³

COULOMBE, ROB⁴

Plant, Cell & Environment; Jan2006, Vol. 29 Issue 1, p138-150, 13p

Utilizing Untapped Water Sources

The Interflow Capture & Storage (ICS) idea seeks to reclaim water that is lost from the site via subsurface flow and seepage.  By strategically placing a number of well-graded gravel trenches across the width of the farm that penetrate down to the impermeable clay layer, subsurface groundwater flows can be recovered and stored in cisterns placed throughout the site.  Both filter fabrics and impermeable layers will be used to facilitate the collection of groundwater.  The water in the cisterns can be stored with minimal evaporation until needed for growing crops.  During the winter, snow could be loaded into the cisterns through the manhole for use in the spring.  It should be noted that the capacity of the cisterns would be much lower than the farm currently demands; it will function mainly as a supplement to alleviate the current demand.  To further increase storage capacity, an impermeable fabric may encompass the downhill side of the gravel trench, so that the pores can act as more storage area.  Excess water or overflow would simply run over the impermeable layer and re-enter the interflow region.  It would then be captured by the next gravel trench and row of cisterns.  The gravel trenches would not affect crop area; filter fabric and a layer of topsoil would allow normal farming of the area above the trenches and cisterns.  Access to the cisterns for maintenance is afforded by the manholes; these also function as inlets for snow storage.

Andrew Kracht

Christina Duncan

Tim Olson

Living Terraces

In farming environments with slopes, heavy seasonal precipitation, and poor soil structure, there is surface runoff. This runoff is bad because it is a direct loss of water to the plants and furthers soil erosion. By terracing the garden beds, we can combat this problem by creating boundaries where surface water has a place to infiltrate the soil. This will help detain water and allow water to penetrate to deeper plant roots.

Our spin on conventional terracing is to make the terrace walls out of straw bales inoculated with fungal mycelium. The bales are wrapped in burlap to act as a moisture barrier and a small barrier from competitive organisms. The bales are placed like bricks in the desired shape and backfilled with soil. Because of the strength and net like form of fungal mycelium, the mycelium will hold the decomposing straw bales together. Stakes driven vertically into the ground will provide the wall with resistance to soil pressures. The fungal colonies could survive for a couple years depending on decomposition. Eventually, the bales would shrink and lose nutritional content necessary for fungal growth.

The benefits are three fold. First, as the fungi eat the straw bales, they will produce mushrooms for food (once, possibly twice per year). Second, as the fungi break down the bales, the bales become nutrient rich organic matter that can be tilled back into the soil to improve soil quality. Third, these terraces are temporary and movable, so any farmer can change the setup as they need.

This system could vary by region by manipulating the fungal inoculants species, its grown medium (straw, logs, etc.), and what is done with the used substratum. On a farm with livestock, it may be used as food.

Brennan Cassleman and Danny Tappel

Multi-Purpose Water

 This algae wall system is double-layered and has clear spaces left in it to allow for maximum control of thermal mass, light, and shade. The wall can be rotated in different seasons to allow more or less light to pass through. The system can be used to heat a radiant floor system during the day, and has sufficient thermal mass to provide heat at night as well. In the summer months, the radiant heat can be turned off and the window opened. The algae wall will provide shade, and the extra heat gain will be let off through the open window to minimize heat gain during warm days. Since algae thrives on sunlight, the algae will become darker and more dense during the summer months, providing even more shading. Algae walls are usually maintained at plants where CO2 is being produced constantly. Since many farm and agriculture processes produce CO2, the algae can be fed by farm by-products. The color and density of algae will then become an indicator of CO2 production on the farm. The by-products of this process are biogasses which can be used for a number of things including running engines or converting to electricity.

Heated/Cooling Silos for storing snow

Since snow will need to be stored on the farm to harvest water for use, an effective storing protocol will need to be used.  Heating/Cooling silos would be a great way to store snow since grain silos are already used on farms and the same technology can be applied to snow, plus old grain silos could be recycled to make new ones in this location.  The silos could be placed arbitrarily around the farm, with however many we might need.

The heating and cooling cycle will occur periodically corresponding to the second graph above.  Since we need to store as much snow as possible, the snow needs to be melted so that it is in its most compact state.  This water that we get from the snow can then be stored at a warm temperature during the winter.  Once we have this water, it can then be cooled during the summer so that it can be used for cold water applications, whatever that may be.

Harvesting Snow

Harvesting water from rain and snow melt from the 10 acre site will only yield around 100,000 gallons per year when the farm uses 500,000 gallons. This will certainly help our goal of being off the grid, but it will be difficult to collect all the precipitation that lands on our site. Harvesting snow from the surrounding area will allow for us to potentially collect all the water we need for the farm. 500,000 gallons of water equals 66,845 cubic feet and depending on the density of snow fall, it will be about 800,000 cubic feet of snow (just under 3000 truck loads of snow). Assuming it would be possible to collect this amount from the area, the problem lies in the storage of the snow. In order to have an efficient system, it would be best to first melt to snow to reduce the size of storage tank. The total storage required will be 3 tanks that are 30 ft dia. and 32 ft tall (calculations).

Having the correct amount of water for the farm will be great, but if it is unusable what is the point. With all the pollutants that are on the road (deicers and oil) the snow will have to be cleaned up before it is stored and used on the farm. Once the snow is brought up to the farm, it can be placed on a melting pad that will be able to filter out all the pollutants. Pervious concrete is able to remove nearly all off the pollutants and allow the melted snow to percolate down into the underground tanks so that it can be used during the dry season. The melting pad could be the parking lot at the farm because during the winter there will not be anyone trying to park there or just a large area so that no other pollutants are added.

 

Symbiotic Relationship Through Nanotechnology

Molecular Water Collectors and Distributors

Water conservation and efficient water utilization are extremely important functions for the Smart Farm. Out of the 500,000 gallons of water the farm uses every year what is the actual water consumed for production of crops? How can we determine the plants water needs when so many factors exist? Factors such as run off, evaporation and transpiration make the job of watering crops efficiently very difficult. It would be nice if we could converse with the plants, but unfortunately we can’t. However, what if we left it up to soil surrounding the plant? What if we could place, on a molecular level, a system that feeds the plants when they are thirsty and stores the necessary water when they are not?

My idea combines two technologies to create a symbiotic system of retention and collection. The retention portion utilizes a hydrophobic sand layer to create a new water table. This is to allow ample time for the second part of this system to react, but it is not meant to be an absolute retention device. The water will still have a path to flow outside the farm. The Nanotube blanket is the second part of the system. It is formed by a patchwork with trillions of Nanotube strands woven together. The Nanotubes react to pressure differentials and in an environment of saturation they suck water in very quickly. The reverse is also true. When the soil is dry they will empty their contents of water to feed the surrounding root layer.

Hydrophobic Sand is in production now and its research is mainly aimed at desert/arid regions. It is being produced at around 3000 tons per day. One ton of this silicate coated sand could cover 10 square meters with a layer being around 10 centimeters thick.

The idea for the Nanotube Blanket is taken from research being done by a few scientists at the University of Main who were curious about waters behavior at the molecular level. The experiments are done on the virtual level. A tiny tube of carbon atoms, called nanotubes are placed into a virtual pool of water. The Hydrogen bonded water molecules, only a single molecule wide, enter the tube in quick bursts. The interaction between the carbon and water molecule mimics chemical modification of the Nanotube causing it to empty or fill up.

Raised Beds

A great way to increase water conservation at the farm is byconstructing raised beds. In this diagram we see a raised bed made from bamboo,however, they can be built using several different materials or even nomaterial at all. If material is used, it can easily come from recycled matterfound on the farm (e.g. from the structure).

Benefits of raised beds is not limited to water conservationand includes an increase in SOM (soil organic matter), a decrease in soilcompaction, easy accessibility to crops, improved soil conditions, greateryields, and a decrease in runoff. Water conservation is accomplished in thisdesign by concentrating the water to one area. The best irrigation system touse with raised beds is drip tape, a practice already implemented at thesmartfarm.

Another way in which water is conserved is by the increasein water holding capacity. First, SOM is increased as a result of lesscompaction and an increase in topsoil. SOM is directly linked to water andnutrient uptake. When there is more SOM, plants are able to take up theseessentials. Think of SOM like a sponge...

The confinement of raised beds will also aide in keeping theorganic matter (crop residues, compost, etc) where it needs to be, near thecrops! Organic matter increased SOC (soil organic carbon), which then improvesbeneficial bacteria.

The benefits of raised beds are endless and could serve as agreat tool in conserving water at the smartfarm.

Misha Manuchehri

_________________________________________________________________Hotmail: Trusted email with powerful SPAM protection.http://clk.atdmt.com/GBL/go/177141665/direct/01/

Turn of the aquifer tap: we have enough precipitation

Water Requirements and Precipitation

The five acre organic farm receives approximately 2.9 million gallons of precipitation per year. During the growing season (April through October) the allotment is around 1.2 million gallons.  For the cold season, (November through March) the allotment is around 1.6 million. Given that this is far in excess of the .5 million gallons of irrigation water needed to produce crops of the current variety, we should only need to capture and store a sufficient quantity of precipitation during the off season to meet the current needs of the farm.

The proposal is to install French drains on the topographical contours of the farm to collect precipitation surplus at saturation and route the water by way of tile lines to cisterns, connected in series, and draining terminally to a pond.  The pond can act as a collection point for subsoil water surplus, for rainwater catchment from structures, and for greywater recycling. 

Spoils from the trenching for the drains serve to cap the drain trenches and create berms that collect surface water, preventing erosion and creating micro habitats for both drought tolerant perennials and moisture dependent annuals.

The pond at the base of the collection system creates a habitat for fish and other aquatic creatures, provides a filtration system for waste water, and a nitrogen enriched  source for irrigation in the summer months.

The Wall Machine

The Living Wall, or the Wall Machine is from the concept of a living machine, but retooled so that it can be both architectural, visual, and scaled to a single aparatus.  A living machine is the human constructed natural process that cleans water through bacteria cleansing and filtration.  All the living machines I have researched are very large, requiring a greenhouse and very large tanks.  Similarily, these living machines filter about 2500 gallons of water a day.  The question was, "do they need to be so big?" If it could be scaled to lets say a singular toilet, where the person using it is in direct control over their waste and water treatment, then could it perhaps be integrated in a way that is architectural and modular? This is my attempt at doing so. 

Water Mashup Ideas

In developing our ideas about WATER, its use and capture on the smartFARM, we have developed the following questions.  To examine these and download individual questions, please visit our Flickr Page.

The first three photos in this set are the three groupings of ideas addressing water CONSERVATION, DETENTION, and PLANNING.  When you travel to the Flickr Page the photo file names are coded with a C, D, or P to correspond with these groups.  Enjoy!