Reliable Delivery
The more one understands about Colorado water law, the clearer become the local issues driving our needs for potable and irrigation water, and the procurement of same from various sources. Priority of rights is such an issue, since the value of water in a certain basin, such as the N. Poudre River, varies according to the date of adjudication. When water is in short supply, a condition that is inevitable, senior rights owners issue a call on the river, and the district manager then shuts down diversions of non-adjudicated water, then limits diverters to just their adjudicated right, then, progressively, more and more junior rights until the senior demand is satisfied. So, it is generally worth-while to buy reasonably senior rights at higher cost per acre-foot (ac-ft, 325,829 gallons) to assure more reliable delivery.
But when many rights are pooled by a company and sold as company shares, they are apportioning a variety of rights to many share-holders, so in times of short supply, each share-holder gets the same proportion. A share that, say, deserves an ac-ft in good times, may get 70% or 0.7 ac-ft, just as every other share receives, even though the company owns rights of various seniorities. Likewise, a water district contracted to process and deliver potable water to its thousands of customers has suppliers of many different seniorities, but it apportions water equally to all its customers, who might be rationed a fraction of their usual amounts. Consequently, seniority is more important to one who is buying rights from one farm to transfer it to another farm than it is to us, transferring water from any farm to a district that will blend it with everyone else’s water, apportioning it equally to its customers.
Because downstream water rights are not to be impaired by junior upstream rights, the yield of a basin is not allowed to be reduced at times of low flow. So, because Dry Creek is perennial, it derives water from the ground that may seep from the Poudre River upstream of Airpark, or, more likely, from seepage from the large Laramie and Weld Canal, traveling in the shallow alluvium southwards across the Airpark and adjoining lands to discharge at Dry Creek and the Poudre. Shallow alluvial wells are closely monitored because they would impact the stream to which the groundwater discharges. An augmentation plan would be required of a new well user, requiring make-up of the reduced river flow from some other source. Just because we want better foundation conditions, we cannot sink drainage wells to lower the water table. Anything we do to reduce the discharge to the river or Dry Creek would have to be compensated. A better consequence would be to increase discharge, and that is the direction we are going, and in that case, there is a possibility of convincing the authorities to permit it.
When lands are irrigated, most of the water is dissipated by evapotranspiration of the plants, but some infiltrates the ground, flows laterally and ends as return flow to the river. Downstream users rely upon such sustenance, so it is forbidden to recapture and re-use one’s own return flows, which are considered property of the downstream diverters. On the other hand, waters imported into a basin are waters that have not been there before, so they can be re-used to extinction without regard for downstream rights. Thus Colorado Big Thompson (CBT) water is treated differently than North Poudre water, having more value because it can be re-used about 2.7 times. N. Poudre water has historic uses: at any given time, say, when pre-1940 rights are being satisfied, but all post-1939 rights are shut off, the basin yield is the sum of all instream flows and all return flows, including snow-melt, springs, irrigation runoff and interflows (shallow groundwater) and sewage plant effluent. Nothing can be done within the basin to diminish such yields, which belong to the pre-1940 rights downstream.
A changed or transferred water right will retain its priority, but cannot be allowed to negatively impact the yields. For instance, if farmer John is willing to sell his irrigation right to another farmer, he can sell the amount that he has customarily consumed. Let’s say he has always diverted 100 ac-ft per year for his beet crop, which has consumed 75 ac-ft by evapotranspiration, while 25 ac-ft have returned to the stream, mostly by interflow through the alluvium. Farmer William, the buyer in some other part of the basin, can divert 75 ac-ft to his newly-irrigated onion patch, while farmer John covenants that he will never again divert his former 100 ac-ft allotment. 25 ac-ft pass by his headgate, maintaining the streamflow unchanged. But if farmer John’s water were from the CBT project, he could have sold 100 ac-ft, not 75 ac-ft. But since it is NP water, farmer William creates some new return flows, since he can’t completely consume his purchased 75 ac-ft. Other owners on John’s stem of the river are protected from damage, as are users downstream of William.
The consumptive use of irrigated acreage may be about 1.5 ac-ft/acre. Thus, if we have to furnish, say, 285 ac-ft to Airpark Village, we would need to dry up about 190 acres of farmland. It has been calculated that a share of the Water Supply and Storage Co. (WSSC) yields about 84 ac-ft, so we could satisfy our demand by buying and transferring about 3.4 shares of WSSC stock. Eastern Laramie County Water District would calculate our demand at 413 ac-ft, according to their multi-family criterion and irrigation needs. In the interest of minimizing the number of shares to purchase, we could either postpone the last purchase until the needs are well defined, or to work towards approval of means of recycling the water we do buy.
It should be noted that storage of water plays a vital role in sustaining dry-season flows. Snowmelt in high places yields tributary flows, as do springs from ground waters recharged earlier by snowmelt and rain. Throughout the watershed, grazing lands, woodlands and farms as well as urban areas accept precipitation (in part), which returns to the stream as interflow, the shallow groundwater fluxes. Vitally important is reservoir storage, such as WSSC’s Long Pond just North of Airpark Village, which is filled in Spring and emptied in late Summer to satisfy irrigation and domestic needs when stream flows peter out. Any storage pond built on the Airpark site could be beneficial for water rights downstream, but would have a detrimental effect on flood management because the site is at the downstream end of the Dry Creek watershed. The effect of such an on-stream pond would be to delay run-off from Airpark to the Cache la Poudre River, more nearly coinciding with any flood peak generated in the headwaters. But off-channel storage for late-season irrigation could be beneficial, minimizing the irrigation water that would have to be imported from some distant farm.
Water Table
It seems evident that a great deal of seepage must occur from the Laramie and Weld County Canal north of the site. It nourishes Lindenmeier Pond, and sub-irrigates thousands of acres of lush grassland between the canal and Dry Creek, including much of the Airpark. Loren Maxey harvests hay in abundance without irrigation, and some wet areas have been noted. The water table is close to the surface, posing a potential problem for developers of the property. It is proposed to drain these areas to the depth of sewer lines by placing these pipes in coarse granular bedding material that doubles as a permeable drain leading to points of collection, probably along the flood channel excavated for Dry Creek. The immediate effect of lowering the water table would be to salvage about one foot of evapotranspiration (ET). It remains to be seen what wetlands mitigation may be required. Aerial photography suggests that about 80 acres of lush grassland might be drained to yield about 80 ac-ft of water.
Irrigation Demand
Not all interflow is free for our consumption, since it currently sustains perennial flow in Dry Creek. A man-made drainage system would deliver the same flow that is entering the property from upslope, but the discharge would be enhanced by the amount of salvaged evapotranspiration. I would propose to make available at least some of the salvaged increment of 80 ac-ft, so that it may provide for some of our irrigation needs, for lawns, trees and hedges. There will be a positive net contribution to return flows because development of Airpark Village will cover about 4,200,000 square feet (sf) of the total 6,000,000 sf with impervious surface that dissipates only a small amount of water evaporated from surface detention. The lawn areas amount to about 1,200,000 sf and mulched areas about 600,000 sf, so irrigation demand (according to Elko’s criteria) is 0.086 ac-ft/1000 sf for lawn, and half that for mulched areas, requiring a total of 128 ac-ft for irrigation, 80 ac-ft of which could be captured from the drain system. Irrigated areas would total about 41.3 acres, with about 3.1 ft of water applied, 1.5 ft consumed, providing 1.6 ft or 66 ac-ft of return flow. 48 ac-ft of transferred water from some purchased source would be the source of some of that return flow, the rest salvaged from the original grassland.
Another onsite resource that could be utilized is gray water. I define gray water as all drainage from showers, baths, wash basins, laundry and kitchens except discharge from garbage grinders and toilets. The latter category, called black water, is to be processed as sewerage, and its effluent released to the Poudre River. Of all domestic and commercial water, it is expected that the black to gray water proportion is about 1:4. The expense of a separate plumbing system for each must be factored into the feasibility, if gray water is to be treated and re-used. If an assumption is made that commercial properties would discharge gray: black water at a 1:1 ratio, it seems unworthy of salvage, so their effluent can go directly to sewerage. But from domestic units, the yield of gray water could be 80% or 221 ac-ft., which proves to exceed our irrigation needs of about 146 ac-ft. (according to Elco’s formula for lawn and mulched areas). If any of the gray water is applied as irrigation water for landscaped areas of domestic and commercial developments, sewerage treatment charges would be correspondingly reduced during the irrigation season, as well as our demand for purchased potable water. There is no current state regulation concerning the application of gray water as substitute for raw or processed water, nor is there a prohibition on it. The City of Fort Collins has had mixed experience with gray water irrigation, having failed to satisfy sanitary conditions at a municipal golf course. They are currently applying gray water to a corn field at Prospect and I-25. They traded gray water for potable water at the Rawhide Project. The gray water is used for cooling, and the potable water supplies the Budweiser brewery.
Domestic Demand
The quantities can be estimated from Elco’s requirements, which are 0.276 ac-ft per living unit since only multi-family quarters are contemplated. For 1000 units, domestic demand would be 276 ac-ft. In addition, we propose 35 acres to be devoted to commercial uses. Based on current usage in the industrial park south of Airpark, Elco estimates commercial demand to be about 0.5 ac-ft per acre, thus requiring about 18 ac-ft, about half of which is for irrigation. Total demand for potable water, based on Elco’s criteria and assuming we buy no irrigation water, would be about 285 ac-ft.
Kemp Custer at the State Water Quality Control Division, (303) 692-3574 says that only sub-irrigation (at the root zone) can tolerate gray water application. We know that aerobic bacterial action is very efficient in organic soils, such that return flows pose no biological hazard. Not so if gray water is applied with sprinklers. Fortunately, drip-irrigation systems have come into popularity using raw water, and their cost is competitive with sprinklers. We can benefit from California studies and practice of gray water use. It may be desirable to process it in some rudimentary fashion, by ponding and oxidation, for instance. Solids and floating matter, if any, could be sent directly to sewerage, decanting (from mid-depths) gray water that is particulate-free, essentially, then sent to landscaped areas for sub-irrigation application. Sub-irrigation is neither feasible nor desirable in most winter months, so all gray water would flow to sewerage at those times. But gray water irrigation would have the great benefit of reducing our potable water demand from 413 to 285 ac-ft. Two sources of irrigation water make that possible: the 80 ac-ft projected to be salvaged by reduction of ET, and 221 ac-ft of gray water from domestic units. A near-term objective of ours should be to obtain approval for capture and use of the drainage water and the gray water, since both together, or gray water alone could save us the purchase of about $1.M of the cheapest shares (discussed below). Because the drying of precious farmland is not in the public interest, we can show how innovative recycling can benefit the state. A developer that is willing to spend $1M on gray water collection and treatment to save $1M in water transfers (up-front) should receive kind consideration.
Whatever we propose, it should show a net benefit to downstream owners of water rights. In the river stem in which the farm is situated, we would be diverting only that amount formerly lost to ET by crop-irrigation of 190 acres. Mention savings of water from evaporation and canal seepage. By dewatering for construction part of the Dry Creek watershed, we can claim about 80 ac-ft salvaged from the former grasslands. We propose to transfer about 285 ac-ft into the Dry Cr. Watershed, from which about 64 ac-ft of collected black water (20% of 276 and 50% of 17.5) should create a new return flow to the stream amounting to at least 60 ac-ft. If household consumption is estimated conservatively at 20 ac-ft, 201 ac-ft of gray water plus 80 ac-ft of salvaged ET would supply the irrigation needs of 146 ac-ft with 135 ac-ft left over. Gray water not used for irrigation goes directly to sewerage, so should be minimized by using gray water in preference to drainage water, which can be released directly to the stream along with other return flows. Landscape irrigation of about 41.3 acres will also produce return flows, of about 25 ac-ft. The net increase of Dry Creek flows may prove to be about 220 ac-ft (ET salvage, 80 + black water, 60 + unused gray water, 55 + irrigation returns, 25) as a result of introduction of 285 ac-ft from some other, unaltered part of the watershed. So how can there be a complaint if we do some innovative, ecological re-use ?
There is a precipitation component to the inflows to the property, and since it is underlain by pervious alluvium, there may be about 20% recharge to groundwater. But the 96 acres of impervious roof and pavement will intercept precipitation, normally about one foot in this area and dissipate some, perhaps 10% by evaporation, so some 86 ac-ft may run off directly to storm sewers and channels and to Dry Creek. There would be a positive change of about 67 ac-ft to stream flows caused by the impermeable surfaces (96 X .90 – 96 X .20).
In summary, the demand-side of the water equation for the LLC is defined by Elco to be 413 ac-ft, but if we can prevail in application for the right to re-use the gray water, or failing that to use salvaged ET, our need may drop to 285 ac-ft to service 1000 multi-family units plus 35 acres of commercial properties assumed for thee calculations. The supply-side of the equation is to be provided by purchase and transfer of surface water rights, drying up some unspecified farm(s) of about 190 acres. There are available shares of several water companies, either from trans-mountain diversions or from the North Poudre River. These are discussed below, from most costly to least.
The Windsor Reservoir and Canal Co. has very recently made it known that they will sell up to 2200 ac-ft of very senior rights, not available for sale since 1935. Being trans-basin water from the Laramie River, there is no return flow requirement, so can be used 2.7 times to extinction. Because the Laramie River is tributary to the N. Platte River, there may be other considerations. Their agent, attorney Butch Sommermeyer, (970) 498- 9900 says it’s better than CBT water, and is asking $14,000/ac-ft. Our 285 ac-ft could cost $4 M.
Elco manager Webster Jones, (970) 493-2044 says that they would require engineering studies to establish specific data on reliability and deliverability of the Windsor Canal water. It is rare for such water to be on the market, and may signify hard times for the owners. Its existence drives the supply side of the market, in our favor.
Colorado Big Thompson water, the former Bureau of Reclamation trans-mountain diversion from the Colorado and Granby Reservoir via the Alva B. Adams Tunnel amounts to a nominal 310,000 ac-ft, but deliveries vary from 50% to 100% from year to year. It is mostly make-up water for eastern slope users, so variations have been inverse to eastern-slope stream flows, greatest when local water is in short supply. However, in 2004, abnormal snow-pack conditions in the Colorado R. watershed have, for the first time, restricted deliveries, this time to 50%. For such reasons, Elco credits an ac-ft share of CBT water at 0.7 ac-ft, the average delivery and utility to Elco.
There are plenty of CBT shares available right now, at a price generally of about $11,500. The high cost reflects the fact that they are used by 120 entities, including the cities of Ft. Collins, Boulder, Greeley, Loveland, Longmont and Broomfield, plus three water districts serving over a million acres. It is easy to process transfers and exchanges through the water court, by reason of familiarity. Shares sold in 1964 for $100, in 1990 for $1500, and in 2000 for $15,000, the peak reached in anticipation of a building ban. When that referendum failed, the price fell in 2001 to $10,000, rose in 2002 to $13,000 and declined steadily thereafter to its present level of $11,500, probably due to availability and a faltering economic recovery. As an index to the water market, it is to our advantage as a buyer to project a continuing decline of the prices, but if you bet on recovery, the price could rise. Note that the recyclability of the CBT water is a factor: it can be re-used 2.7 times because it is water that has never been in the watershed before, so cannot be counted upon by downstream users.
The third potential source are shares of North Poudre Irrigation Co., whose origins are all within the basin and cannot be transferred out of the basin. That makes them cheaper, but advantageous because they are mostly CBT water (NPIC owns 40,000 shares of CBT) plus a variable N. Poudre component. This year, each NPIC share consisting of 4 shares CBT plus agricultural water (N. Poudre) yields only 3 ac-ft, 1.5 ac-ft from each source. Most years, the total yield of NPIC shares is 5 to 7 ac-ft, currently selling for $40,000 to $42,000 per share, or about $13,333 per ac-ft. That should be compared to CBT water at $11,500/0.7 = $16,429 per ac-ft of credit with Elco. A very knowledgeable source of information on N. Poudre water is their secretary, Sharon, at (970) 226-1405 or 568-3612. Web Jones of Elco says NPIC water is more reliable than its CBT component due to sources on both east and west slopes. Since Airpark Village is in the N. Poudre drainage, the fact that NPIC shares cannot be traded outside the basin is only important if we should have to resell any shares we buy.