APRIL 2008 ISSUE

According to the April 1, 2008 “Nevada Water Supply Outlook Report,” (snow survey http://www.nv.nrcs.usda.gov/snow) March was a dry month. All Nevada and Eastern Sierra watersheds received less than normal precipitation for the month. Values ranged from 87% of average for the Snake River watershed in Northeastern Nevada to 12 % of average for the Lower Colorado watershed. Due to the storms from December into February, water year precipitation for Northern and Northeastern Nevada and the Walker River watersheds remains near to above average. But the other Eastern Sierra, Eastern Nevada, and Lower Colorado watersheds were at 70 to 83% of average water year precipitation as of April, 1. The snowpack is holding out fairly well. The snowpacks in the Carson River and Lower Colorado watersheds were 82 and 81% of average, respectively, on April 1. All other parts of Nevada had greater snowpack. The Northern Nevada watersheds still had over 100% of average snowpack, with the Lower Humboldt River watershed at 120%, the high. Snowpack, precipitation, and predicted summer streamflows for all Nevada watersheds are 150 to over 200% of last year’s values.

According to the National Weather Service’s Climate Prediction Center, Nevada’s weather for the next 3 months is expected to remain generally dry. As a result areas of drought are expected to persist.

     
U.S. Drought Monitor and U.S. Seasonal Drought Outlook 
www.cpc.ncep.noaa.gov/products/expert_assessment/drought_assessment.shtml

 
Long Term Palmer Drought Severity Index
www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_monitoring/palmer.gif

MARCH 2008 ISSUE

According to the March 1, 2008 “Nevada Water Supply Outlook Report,” (snow survey http://www.nv.nrcs.usda.gov/snow) all surveyed watersheds were at least at 100% of normal snow pack, except the Northern Great Basin area which was at 99% of normal. The Eastern Nevada area had the greatest relative snow pack at 134% of normal. Eastern Sierra watersheds ranged from 102% of normal for the Truckee River to 115% of normal for the Walker River. While Nevada’s snow pack is doing much better than last year, the month of March has been dry and the good snow pack reflects the abundant snowfall from December through early February. With the exception of Salmon Falls Creek, the Owyhee River, several creeks in northern Surprise Valley and the Truckee Meadows, all other watersheds in Nevada are predicted to have average to above average streamflows through July. The drier areas are predicted to have greater than 85% of average streamflows through July.

According to the National Weather Service’s Climate Prediction Center, Nevada’s weather for the period March through May will be warmer than normal, being slightly warmer in northwestern Nevada with increasing departure from normal going southeast through the state. Western Nevada and the northern edge of the state are expected to receive around normal precipitation. The eastern half of the state is expected to be slightly drier than normal. Temperatures in the mountains should stay cool enough to maintain relative snow pack levels. As a result the Seasonal Drought Outlook shows persisting drought over southern California and southern Nevada. Mountain snow pack will produce spring runoff. To the north, improvement is anticipated over the northern Great Basin.

FEBRUARY 2008 ISSUE

In Nevada, and much of the west, drought is predictable and common part of the climate. Climate change could exacerbate drought issues in the Great Basin. BLM drought planning and management is becoming a routine part of public land management.

CONCEPTS FOR THIS WEBPAGE

This web site provides BLM Nevada’s drought information and direction. It is intended for use by BLM personnel, public land users, and the public. A public website allows everyone with an interest to see the information that BLM is using in its drought planning and management. Although many of the principles behind BLM’s drought guidance are well established, using a website allows updates when weather conditions warrant. BLM Nevada’s drought management guidance and policies are designed to meet or comply with our multiple use mandate, land use plan objectives, other applicable legal and regulatory requirements, and achieve land health. Plus, if the predicted increase in weather variability and extreme events happens, the value of a venue such as this may increase.

While other topics will appear on this web site, the main subjects will be precipitation, expected plant growth, and livestock grazing management. BLM authorizes livestock grazing on most of the public lands in Nevada. Drought has two obvious impacts on public land grazing, reduced forage production and reduced amount and availability of drinking water. Both situations have repercussions beyond range management. Sometimes livestock management has to be modified in response to drought, and sometimes it can be used to manage drought impacts.

This website will be updated monthly from November through May. In the Great Basin this is when the precipitation occurs that determines the amount of vegetation produced in the next growing season. Big storms and unique events might also warrant updates. The Natural Resources Conservation Service’s (NRCS) snow surveys are read monthly from January through April (www.wcc.nrcs.usda.gov/wsf/wsf.html). This is one of the better predictors of water availability in Nevada. By May most grazing management decisions have been made. Although this website focuses on drought, the common weather problem in Nevada, some of the ideas are applicable to other issues.

DROUGHT INFORMATION ON LINE

There are numerous sources of weather and drought information on the internet:

*www.drought.noaa.gov is the National Oceanographic and Atmospheric Administration (NOAA) drought web site. It contains many links, including several versions of the Palmer Drought Severity Index and some predictive tools. The National Drought Mitigation Center link contains historic and planning information including the Nevada Drought Plan.

*www.drought.gov is the National Integrated Drought Information System (NIDIS) website. This site is a treasure trove of drought information. There are many links. In addition to short and long term weather and drought data and predictions, there are sections on planning, preparation, and management. The idea that developed into the NIDIS was an initiative of the Western Governors Association to consolidate and organize drought information along with planning and management tools and ideas so the western states could be better prepared for droughts. Nevada BLM will take full advantage of their excellent work.

*gacc.nifc.gov/wgbc/index.htm is the Western Great Basin Coordination Center web site. In addition to current weather and drought information, this site contains the latest information about fire conditions and fires in Nevada.

BLM OVERVIEW OF NEVADA’S WEATHER DURING THE PAST FEW YEARS

2004
Generally speaking precipitation during the 2004 water year (the water year is 10/1 – 9/30) in Nevada was less than 90% of average across the state, except along the eastern boundary where precipitation was near normal and in southern Clark County where precipitation was above average. Depending on location, this dry spell started in 1998 or 1999 and included the 1999 through 2001 fire seasons. From 2002 through 2004 fire activity in Nevada was comparatively low. This can be partially attributed to dry weather and poor cheatgrass growth. While there was lightning, the cheatgrass was more scattered, so few strikes grew into large fires.

2005
For the 2005 water year precipitation was much above average across the state with much of the southern half of the state receiving over 150% of average precipitation. Approximately 850,000 acres burned between Las Vegas and St. George, UT during the early summer of 2005. These fires got so big because of the continuous cover of red brome, a cousin of cheatgrass that thrives in the Mohave Desert.

2006
For the 2006 water year precipitation was at or above average over most of northern Nevada and average to near average over most of the rest of the state. Most of the precipitation came early in the water year. 2006 was another severe fire year, especially in Elko County, where nearly 1 million acres burned.

2007
In the 2007 water year Nevada received less than average precipitation. Large areas of western and southern Nevada got less than 50% of average precipitation. While almost 1 million acres burned again in 2007, most of it happened during a 2 week period in early July.

2008
From October 1, 2007, the start of the 2008 water year, through November the dry parts of the state, the Sierra watersheds and southeastern Nevada stayed dry. While most of the northern border watersheds were at or above 100% of average precipitation.

Winter storms started hitting western and southern Nevada early in December and continued into early February. All the Sierra Nevada watersheds in Nevada are now at or above average snowpack. Summer streamflows are expected to range from over 80% of average in Nevada’s Snake River tributaries to over 120% of average in the Lower Colorado River watershed.

BLM LANDS

Drought and fires are impacting values and uses on BLM lands (http://www.blm.gov/nifc/st/en/prog/fire/more/gbri.html) including; livestock grazing, wildlife habitat, and wild horse and burro habitat. The relationships between drought and fires are changing as the cheatgrass fire cycle converts plant communities of relatively long lived perennial species to communities of annual plants. These changes are converting Nevada’s rangelands from a fairly reliable year long source of forages from a mixture of grasses, shrubs, and forbs to a source of spring forage with forage availability during the rest of the year being much less dependable than in the past. A small amount of spring soil moisture, as might occur during a drought, can still produce an abundant cheatgrass crop. Because the cheatgrass completes its annual life cycle before most of the native plants it can use up all the available soil moisture before perennial species start growing. This early flush of cheatgrass can obscure the pending absence of forage during the rest of the spring and summer and maybe through the winter. On the other hand, once it dries out the cheatgrass is very flammable and can perpetuate the cheatgrass fire cycle.

Livestock grazing is a common use of the public lands which can be managed to mitigate to varying degree drought impacts to vegetation, water, and soils. That the permitted livestock use on an allotment needs to be adjusted in response to drought is not a reflection on a permittee’s management of the allotment. Grazing management change is a reaction to drought. Livestock grazing can be controlled; we cannot make it snow or rain when we need the water.

Two different livestock management approaches are often employed on BLM lands that help mitigate the biological impacts and management disruptions of normal drought. The most common is conservative stocking levels. Where stocking levels were based on conservative forage production estimates, normal droughts may not require livestock management adjustments. The other approach is intensive livestock management. On these allotments lower production during drought can often be compensated for by more frequent pasture changes or placing livestock in rested, higher, or wetter pastures. Regardless of management prolonged drought can eventually lead to difficult management choices by livestock owners. During extended droughts, ranchers sometimes have to move or sell a portion of their base livestock herd.

LIVESTOCK GRAZING BEFORE, DURING, AND AFTER DROUGHT
Nevada State Office Policies and Direction

The most recent BLM national drought instruction memorandum (IM) was issued in 2003. The concepts and guidance in WO IM 2003-074, “FY 2003 General Drought Management Direction,” remain applicable and will continue to be BLM Nevada’s approach to grazing management during drought conditions. This IM explains a four phase approach to management for drought; early assessment, pre-season assessment, continuing assessment, and post drought phases. Link to the IM. The approach in this IM was adapted from drought preparation ideas that are now available on the NIDIS web site (www.drought.gov then pick “Planning” from the top banner).

BLM Nevada will make livestock use adjustments due to drought on a case by case basis in compliance with our multiple use mandate and applicable regulations. Actions to change livestock management will preferably be developed cooperatively by the permittee, other stakeholders, and BLM at the local level and implemented by agreement.

Often BLM’s first step in responding to drought is contacting the permittees and describing the conditions of concern and resource values at risk. This is often done with a letter. Discussions should begin early in the winter, at least three months before turn out or when changes need to be implemented, so the permittee can plan ahead.

Some relevant topics may include:
• Current conditions, perennial plant production and vigor has been effected by two years of low precipitation. One good winter snow storm does not negate the impacts of two years of drought.
• Areas not meeting rangeland health standards.
• Fire rehabilitation seedings and other burned areas that are two or three years old and might be opened for use in the coming year.
• Areas that had no or little annual production the previous year, especially due to drought.
• Areas with apparent plant mortality from any cause, persistent drought, Aroga moths, cheatgrass die off areas, uncertain causes.
• Areas with known poor conditions.
• Interactions among herbivores; wildlife, wild horses and burros, and livestock.
• Alternative sources of livestock range or forage.

Initially, all options are available. Allotment or area analysis and coordination will determine what management is appropriate, available, and applicable. In cases where agreement on necessary actions cannot be reached, BLM may issue decisions or full force and effect decisions in compliance with 43 CFR 4160 and 43 CFR 4110.3-3(b). Issuing decisions will be the last resort, after coordination and negotiation have been unsuccessful. If an emergency situation arises that meets the criteria in 4110.3-3(b), BLM could issue a full force and effect decision.

Human nature makes drought planning during the winter difficult. People are optimistic that it will rain and snow enough at the right times for a good year. This often results in putting off decisions until the last minute. The situation in the Great Basin is further complicated by cheatgrass. While a year may turn out to be drouthy with poor production of perennial species, one well-timed storm can still produce abundant cheatgrass setting the stage for a green spring followed by large wildland fires.

WILD HORSES AND BURROS

BLM Nevada’s FY-08 budget for planned and emergency wild horse or burro gathers has been allocated. This means that between now and September 30, 2008, unplanned emergency BLM wild horse or burro removals in Nevada are unlikely. The most recent national direction that talked about horse and burro management and drought was WO IM 2004-151 which said that adjustments in wild horse and burro numbers due to escalating problems such as drought would have to occur within existing state removal numbers. It also adopted the four phase approach to drought management described in WO IM 2003-074.

WILDLIFE

The combination of almost 3 million acres burned in the past three years and deep snow in some areas will weigh heavily on some wildlife populations. Mule deer are likely to be the most obviously impacted. Much of the burned area was mule deer winter range. With the loss of sagebrush and other shrubs, the mule deer winter range value of these burned lands is mostly to completely lost until the shrubs recover. Where sagebrush was the common shrub natural recovery usually takes decades.