Water outlook not good, drought is a big questione
Last year's winter and spring were dry and the eastern Utah area was without adequate stream flows in the spring and throughout the summer to keep streams running as they should. But the flow was saved by reservoirs that were nearly full from a near-record snow melt the year before.
This year the area, in terms of runoff, is little better than last year, but not much. However, reservoirs like Scofield and Joe's Valley don't have the reserves of last year because so much was taken out for that drought year. That means supplies and probably deliveries of water to everyone will be down this year.
"Remember last year?" said Randy Julander of the Natural Resource Conservation Service in his monthly water supply outlook report. "Long, hot and dry - every water manager's nightmare? Well, this year is a carbon copy repeat - only with much less reservoir storage. March was the third consecutive month of way below normal snow accumulation. So low in fact that on this month's snow surveys it was common to see the sampling holes and snowshoe tracks from the previous month."
The NRCS keeps track of the snow on the ground, the precipitation, the moisture in the soil and what is in the reservoirs each and every month across the state. This information is put in a report that is released in the first week of every month.
According to Julander, snow melt has already begun at almost all the sites they check (the SNOTEL sites). It is still early in the general melt season, but a lot of places are way down.
According to the report "snow packs across the state are low (62 percent on the Weber River to 90 percent on the Beaver River) and dropping fast. March precipitation was much below normal statewide ranging from 44 percent to 63 percent of average. This brings the year-to-date precipitation to below normal statewide at 77 percent."
Locally snowpack in the Price and San Rafael Basins is much below average at 66 percent of normal, compared to 43 percent last year. While that looks much better than last season, a near 100 percent of normal snowpack would be needed to fill the reservoirs while use downstream from them was going on.
The precipitation in March was also way down from normal. March is one of the wettest month so of the year and it was only 50 percent of normal, "which brings the seasonal accumulation (October to March) to 77 percent of average."
The soil moisture (the water actually in the soil at any given time) is a key because as snow melts the water can either run off into streams for use as storage or it will run into the ground if the soil moisture is low. Right now the soil moisture in the area is at 57 percent compared with 85 percent last year. That means much of the increased moisture over last year's low figures will run into the soil.
Last year reservoir storage in the area was around 80 percent across all storage areas. Now the average in the area is about 48 percent of capacity.
The stream flow will also be very weak this year. While April is the wettest month of the year, the water that comes during the month seldom makes a complete difference in what has been a dry season overall. The stream flows in the area this spring will be between 32-53 percent of average.
Of special interest to the area, the Seeley Fire in the Huntington Canyon area last summer did more than burn trees and then turn areas through heavy thunderstorms into catch basins full of logs and debris. It also will affect the watershed for many years. According to an addendum released by the NRCS after the monthly report, the Seeley fire burned about 48,000 acres, including 18,500 acres of the Huntington Creek Watershed just below Electric Lake in the bottom half of the basin. This constitutes nearly half (46 percent) of the total watershed area of 40,100 acres.
The impact fires have on water supply and stream flow in high?relief areas of the Intermountain West can be complex. Generally in the first few years after a fire, snowmelt can be accelerated due to: (1) carbon/dust/organic material deposition on the snow surface; (2) the volume of standing blackened timber changing the albedo (reflectivity) of the snowpack; and (3) the reduction in canopy cover in areas that formerly sustained evergreen forest. Snowmelt can consequently be advanced as much as six weeks, or more.
These conditions can also lead to greater snowpack losses to wind erosion and sublimation. Conversely, the lack of forest cover can increase the amount of snow on the ground that would normally be intercepted by the forest canopy, and, particularly in the decade or two after the fire, may lead to higher overall April?July stream flow. However, in the first few post?fire years with low snow packs and with long periods between storms, the net effect can be lower overall snow water equivalent on the ground with early melt. Some of the runoff that would normally have occurred in the April?July time frame could happen earlier.
Water supply forecast models are geared to predict the April?July runoff season based on observed snowpack and other variables. There are no data sites inside the Huntington Creek burn area and data used in the hydrologic models are from non?impacted nearby sites. As such, the NRCS anticipates that runoff on Huntington Creek will be shifted to an earlier time frame due to the burn conditions in the watershed and that the April?July forecast is likely to overestimate the April?July stream flow.
These conditions could persist for several years. It is also important to note that the inflow to Electric Lake above the burn area will not be impacted.
With so little snow left to melt on the burn area there is little probability of serious erosion or mass wasting phenomena from the fire area. The remaining snow is likely to melt in small daily increments and infiltrate the soils over the next month or so. Intense precipitation events could trigger mud and debris flows from the burn.