The Royal Gorge Water Study:

A Hodge-Podge of Fragile Sources

An analysis of Royal Gorge's recently published reports, including the eagerly awaited "Water Supply Alternatives" study, finds that their water claims are indeed fragile. Their water sources look good on paper, but fall apart under the slightest scrutiny, and completely disappear when examined closely. This analysis looks first at Royal Gorge's water demand claims, and then moves on to critically examine Royal Gorge's hodge-podge of water supply sources. The conclusion is that Royal Gorge actually needs much more water than they claim, and that only a small fraction of their projected water supply is even robust enough to be called an alternative.

This analysis is based primarily on three sources of information: The Royal Gorge documents submitted to the County in November 2007; the Watershed Yield Calculator published by the American River Watershed Institute, and SLCWD's Surface Water Balance Model for Serene Lakes.

Water Demand:

Royal Gorge's water demand study, found in Appendix C of the Water Supply Alternatives report, was conducted by King Engineering. King assumed a demand of 500 gallons per day (GPD) for single family residences (SFR) and 300 GPD for condominium or hotel units, plus varying amounts for the commercial and recreational facilities in the plan. If these per unit usage numbers are used, then the total water demand can be arrived at from their calculations, provided a few modifications are made. First, King erroneously assumes that large townhomes (2200 to 3400 sq. ft.) use the same amount of water as condominiums (1000 to 2000 sq. ft.) rather than the amount used by SFRs. According to the EIRs referenced in Appendix A, large townhomes should be classified as SFR units, not condominiums. Second, no water was allocated for the cabins, lodge and other facilities in Wilderness camp. Instead King states that the Wilderness Camp water will come from "other sources". For demand projections to be complete and accurate, Wilderness Camp water demand must be included in their analysis, with the "other sources" identified and analyzed.

When the King study is adjusted to classify townhomes as SFRs, and the water usage for Wilderness camp is added in, then the total water demand is projected to be 574 AFY, not 526 AFY as reported by King.

Finally, the water demand study omits landscaping water and water needed to replenish West lake (the recreation Lake) in Lake Camp. The landscape watering needs is given in Summary Table 2 of the King report as 51,000 GPD. This is given as maximum daily demand, but is assumed to be managed by timers, so it would be the same as the average demand for the months of June, July, August and September. This works out to be an additional 4.8 AF per month over that period. Evaporation will also significantly deplete the water level in West lake over the course of the summer. The average evaporation for the Donner Summit area is 2.6 feet over the summer months. Some of this might be replenished by groundwater seepage, but given the solid rock geology, and the amount of proposed development around the lake, it is likely that there will be little seepage, causing West Lake's water level to decrease between 2 and 3 feet during summer. If Royal Gorge intends to preserve the recreational value of the lake, then 10 to 20 AF of additional water would be required each summer to replace this water loss.

Occupancy:

The water studies look at 46%, 75% and 100% occupancy for the new development, but only the 100% occupancy numbers are relevant. It is only common sense that if there is only water for 46% or 75% occupancy, then only 46% or 75% of the units should be approved to be built. The development is not like a campground that can simply close when water runs out, as it will provide homes for people that will need water year-round, no matter what the day to day occupancy is.

In addition, the most critical months for water usage start in June, when the weather heats up, the water demand grows, and the spring snow melt is long gone. One can easily imagine full occupancy then, and through the summer. Full occupancy for just these five months is close to the 46% threshold. If that 46% threshold is reached, will Royal Gorge resort close in October, not to reopen until the following spring? The County has stated that the water supplies need to be studied for full occupancy, and for good reason. Full occupancy is used for this analysis.

Water Supplies:

Royal Gorge has identified eight sources of water. Some of these are reliable supplies, in that one can count upon a minimum amount of water to be available. Some, like High Sierra wells, are marginal, in that their capacity, quality and sustainablity are unknown, and can fail at any time. Finally, there are three sources that are impractical and not worth including as a supply source. Each of these sources are examined below.

Serene Lakes Spill:

This refers to the water that goes over the Serene Lakes dam during the spring thaw and run-off season every year. The Serene Lakes watershed contains many thousand acre-feet of run-off water that re-fills Serene Lakes and then spills over the dam for a short period every spring. The spill starts in either January or February and ends in May or June. Last year the spill stopped in mid to late June, but the amount of spill water in June was minor, only 50 AF, hardly enough to count on, especially during a drought. Drought years simulations using SLCWD's water balance model show that the spill can stop in early May. At this time (mid-January) the lake has not yet filled up and has not started to spill. This means that the only reliable spill months are February, March and April. This contrasts to the Royal Gorge Study that assumes spill water can be used from New Years through the end of June.

Raising the Serene Lakes Dam 6":

Raising the water level in Serene Lakes by six inches will flood many lakeside lots, reach the foundations of several houses, and inundate much of the greenbelt area around the shore. This will cause major damage to the trees and vegetation around the shore, which will be flooded for extended periods. The two islands in Lake Serena and all their trees will be under water. Wind driven waves will further damage the flooded vegetation and foundations. Eventually the flooded vegetation and trees in the "six inch flood belt" will die, leaving a muddy ring.

Royal Gorge argues that the water level during the spring run-off season is already more than 6" above the dam level, so "why not capture that extra 6 inches and use it during the summer?" What Royal Gorge neglects to mention, is that the 6 inch surge is normally very brief and occurs while there is still snow on the ground and when trees and vegetation are dormant. In fact, SLCWD water records for 2007 show that last spring the lake level was above six inches for only a few days in the middle of May.

Royal Gorge's proposal is to raise the dam at the end of the run-off season in order to capture the last 40 AF of run-off. Before that time, the dam would be lowered in order to keep the surge flow from cresting even higher than normal. The spillway records from last May and June (2007) show that the dam would need to be raised before June 1st, as the runoff after June 1st was only around 50 AF. This flood level would remain until water usage drops the lake level by six inches. Again, using 2007 data, the lake level didn't drop by six inches below the dam height until late July. This means that, if the raised dam was in place in 2007, then, instead of a few days of flooding, there would have been flooding from mid-May until Late July, a period of more than 2 and half months. More than enough time, especially since it is during the tree and vegetation growth period, to weaken or kill all trees and vegetation in the flood zone. During wet years, when run-off continues into July, the flood level would remain much later, perhaps into fall.

For these reasons, the 37 AF claimed to be available by raising the dam is not feasible and can not be used as a source of water.

Serene Lakes Water:

Royal Gorge proposes to use a maximum of 35 AF of Serene Lakes water after the spring run-off has stopped. Pumping an additional 35 AF from the lakes will lower their level by six inches over the pumping period. Last year, a dry but not drought year, the water level dropped almost two feet. The SLCWD water balance model, using the drought conditions in 1976, 1977, 1986 and 1987 shows the level would drop by 2.8 feet. If a maximum level drop is set at 3 feet, then the additional six inches would exceed this limit. If a drop of 3 feet 4" can be tolerated, then the 35 AF can be used reliably. Note, however, that there are 200 undeveloped homesites within the existing Serene Lakes Community that have prior claims on this water.

East Lake Storage:

If East Lake is built, which is not certain as many more permitting agencies will be involved, including the California Department of Dam Safety, and as it will require substantial clear-cutting and blasting of a forested area, then it could become a reliable source of 40 AF of water. This would require approximately 80 AF of water to be pumped up from Serene Lakes during the spring run-off season.

SLCWD Well Water:

The water district has two wells that do not meet drinking water standards and have never been used as a sustained water source. Instead they have been considered a stand-by emergency supply, mainly for fire suppression. One is heavily contaminated with manganese and the other contaminated with arsenic. Filtration methods to remove these contaminants, while feasible, are very expensive.

These are fractured granite wells, relying upon water stored in cracks in the bedrock, rather than in traditional aquifers. Because of this it is uncertain how much water is truly available. Documents show that their flow was at one time 105 gpm, and tests are being conducted to see how they perform over 10 days. Wells, however, that produce steadily over several years can suddenly lose production the next year. For example, wells in the Northstar project (see water study appendix A) produced 500 GPM for several years, but then dropped to 200 GPM during a dry year.

Another problem with wells is that they have unknown and unpredictable effects upon the local water basin. Olympic Valley's current well water issues are a good example. It appears that after increasing the well water draw for the newly built condominiums, Squaw creek is drying up. In addition, the 4,000 AF predicted to be available from wells, is turning out to be less than 1,600 AF, half of which may be contaminated.

Extended flow tests during dry years are the only way to determine if a well is a reliable supply of water. If these wells are relied upon to provide part of the water supply, then there is a very real danger that these sources will dry up, or lose a good portion of their production, and leave the development short of water. For this reason the SLCWD wells are of marginal reliability and should not be considered a primary water supply source. These wells should be reserved for short term emergencies.

New Wells on Royal Gorge Property:

Royal Gorge claims to have found wells that may produce up to 10 AF per month of water. These wells, until proven through extended dry year testing as described above, cannot be relied upon as a primary water source, and should be saved for emergencies.

Rainbow Springs Water:

Royal Gorge suggests that they can pump over 5 AF per month over nine miles in distance and 1000 feet in elevation from Rainbow Lodge to the new development. The pipeline would follow Hwy 40. The construction and maintenance cost of such a pipeline, just to provide 32.5 AF each year, is prohibitively expensive. If a two million dollar pipeline construction cost ($200,000 per mile) is amortized over 20 years, then the cost of the water would be around $3,000 per AF, around ten times the current market price. This option is not economically feasible and should not be considered.

Serena Creek Reservoir:

Royal Gorge has proposed damming the Serena Creek canyon approximately one mile downstream from Serene Lakes. According to Royal Gorge's consultants, the massive dam would be a quarter mile wide and 65 to 70 feet tall. The dam would impound up to 600 AF of water with a surface area of around 23 acres. Getting regulatory approval to build such a massive dam, which would flood a currently pristine wilderness, would be extremely difficult. Seismic concerns alone may prevent construction of the dam. Seismic studies of the area (See Royal Gorge's Geotechnical study) indicate that a magnitude 5 earthquake occurred less than 20 years ago just a few miles from the proposed dam. Also, according to the Royal Gorge studies, the proposed inundated area is a trout stream, shows beaver activity, is possible habitat for Pacific Fishers and has rare Ceanothus plants growing in the area. A dam would also block a significant wildlife migration corridor between the North Fork American River and South Yuba River watersheds. Given these concerns, the water from a dam across Serena Creek should not be considered as a viable source.

Conclusions:

A summary of monthly water demand and supply is shown in the following table. The water demand of 47.8 AF per month is shown across the top, with an added 80 AF shown for March in order to fill the East Lake reservoir. These numbers do not include the added 19 AF of water required for landscaping, nor the 10 to 20 AF required to replenish West lake.

The water supply is broken into two sections- reliable supplies and marginal supplies. Raising the dam on Serene Lakes, pumping water up from Rainbow Lodge, and building a dam on Serena Creek are not feasible enough to be included.

The reliable supplies provide enough water only during the spill months of February, March and April. Outside these months there is a shortfall of 39 to 44 AF per month leaving a total of water deficit of 355 AF each year.

Even when the marginal well water sources that may dry up at any time are included, the yearly water deficit is still over 200 AF

The conclusion is that there is very little water available to build much at all, and what water there is may be needed for the existing, yet unbuilt, Serene Lakes homesites.

Water Supply analysis for 100% Occupancy
Water Demand	Acre-Feet
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Total
	47.8	47.8	47.8	47.8	47.8	47.8	47.8	47.8	47.8	47.8	47.8	47.8	574
Fill East Lake			80										80
Reliable Water Supply Sources
Serene Lakes:
Spill Quantity		47.8	127.8	47.8									224
Added Pumping	3.9				3.9	3.9	3.9	3.9	3.9	3.9	3.9	3.9	35
East Lake					5	5	5	5	5	5	5	5	40
Water Deficit	43.9	0	0	0	38.9	38.9	38.9	38.9	38.9	38.9	38.9	38.9	355
Marginal Water Supply Sources
New Wells	10.1				10.1	10.1	10.1	10.1	10.1	10.1	10.1	10.1	91
SLCWD Wells	7.1				7.1	7.1	7.1	7.1	7.1	7.1	7.1	7.1	64
Water Deficit	26.7	0.0	0.0	0.0	21.7	21.7	21.7	21.7	21.7	21.7	21.7	21.7	201
NOTE: Does not include water for landscaping (19 AF), or for replenishing West Lake (10 to 20 AF)