West Slope WUI ProjectHydrology Report Joni Vanderbilt

Chapter 1 Wetlands, Floodplains, Municipal Supply Watersheds, Impaired Waters

D There are no wetlands in the project area.Kl There are wetlands in the project area, but no adverse effects are anticipated.D There are wetlands in the project area, adverse effects are possible.

D There are no floodplains or flood-prone areas in the project area.

£<] There are floodplains or flood-prone areas in the project area, but no adverse effects are anticipated.

D There are floodplains or flood-prone areas in the project area, adverse effects are possible.

Municipal supply watersheds (FSM 2542) include surface supply watersheds, sole source aquifers, and theprotection zones around well and springs.

D There are no municipal supply watersheds or drinking water source areas in the project area.

£<] There are municipal supply watersheds or drinking water source areas in the project area, butno adverse effects are anticipated.

D There are municipal supply watersheds or drinking water source areas in the project area, adverseeffects are possible.

Is it likely that the degree of potential effect of the proposed action on wetlands, floodplains, or municipalsupply watersheds constitutes an extraordinary circumstance.

KINO DYES

Is the project area adjacent to or tributary to a water quality limited stream segment or lake (from current303(d) list or a TMDL)?

DNO [X]YES

List any key public contacts that need to be made on page 1 of this document.

Attach any additional information pertaining to this proposal. This may include requiredBMP's/SWCP's/mitigation, Clean Water Act Worksheet, maps, etc.

£3 The proposal complies with Executive Order 11988 (Floodplain Management).

Kl The proposal complies with Executive Order 11990 (Protection of Wetlands).

IEI The proposal complies with the Clean Water Act.

£<] The proposal complies with the Safe Drinking Water Act.

£<] The proposal complies with Forest Plan management direction.

Hydrologist, Soil Scientist, and/or District Watershed Staff signature: Joni Vanderbilt, HydrologistDate: 12/19/2014

West Slope WUI ProjectHydrology Report Joni Vanderbilt

Affected EnvironmentAnalysisThe best practicable science was used in the hydrological assessment of this project. The relevantscience considered for this analysis consists of several key elements:

•On-site reconnaissance of key areas. Key areas include streams and wetlands within theproject area selected based on aerial photograph interpretation as well as CIS layers. Thisinformation is used to design project units as well as refine mitigation.•Scientific literature (discussed within the specialist report).•GIS information on streams and wetlands.•Integration of the professional knowledge on the part of the Hydrologist with the collectiveknowledge of the project area by ID Team members.•Comparative analysis considering other local similar projects. The effects to the watershedfrom other similar projects in the area have been considered in the analysis (see'Consideration of Cumulative Effects' section below).

Project Location and Watershed Analysis AreaThe majority of the project is within the Mill Creek Watershed, primarily the North Fork Mill Creek andHorse Creek-Mill Creek Subwatersheds. Approximately 240 acres of mechanical treatment isproposed on the edge of the Pack Creek Subwatershed and approximately 50 acres of proposedmechanical treatment is within the Placer Creek Subwatershed.Herbicide treatment is proposed within the North Fork Mill Creek and Placer Creek subwatersheds.

Riparian and Watershed ConditionThe proposed project boundary includes the perennial Mill Creek, as well as a number of intermittentand ephemeral drainages. Springs, reservoirs and ditches are also present within the projectboundary. The West Slope WUI interdisciplinary team visited the analysis area in November of2012. While in the field, the ID team visited a number of riparian areas including two spring areas,South Mesa Reservoir, intermittent and ephemeral drainages. The first spring was located uphill fromFS Road 4651 on South Mesa. Vegetation at the spring included decadent and some sproutingwillows, tamarisk and pinyon/juniper. The spring area was small, approximately 200 feet by 40 feet,with a diffuse water source and no surface water present. The other spring was on Brumley Ridge,downhill and west of private lands. The spring head is located on FS Rd 4882 and subsurface waterflows downhill from the spring and down onto the flat below. Tamarisk is scattered throughout thearea. A portion of the Interdisciplinary Team returned to the project area on May 15th 2014 to reviewproposed treatments within drainages. In general, the morphology of stream drainages is appropriatefor the landscape setting. In other words, excessive erosion and deposition is not evident in channels.Some springs that are accessible for livestock uses exhibit impacts such as dewatering and/ortrample.

Water Quality

The Clean Water Act requires each state to implement its own water quality standards. The State ofUtah has designated beneficial uses and identified water quality impaired segments throughout thestate in a 303(d) list. The State anti-degradation policy applies to all waters located within theboundary of the National Forest. This policy states that water quality is to be maintained with little or

West Slope WUI Project

Hydrology Report Joni Vanderbilt

no degradation. New point sources are prohibited, and non-point sources must be controlled throughimplementation of Best Management Practices (BMPs).

The anti-degradation policy applies to all streams upstream of the NFS boundary. This policystipulates that "...no water quality degradation is allowable which would interfere with or becomeinjurious to existing instream water uses". Both action alternatives would follow Soil and WaterConservation Practices (SWCPs) in order to minimize potential effects to water quality and adhere tothe anti-degradation policy.

The beneficial uses for the watershed analysis area are:

Class 1C - Protected for domestic purposes with prior treatment by treatment processes asrequired by the Utah Division of Drinking Water

Class 2B -- Protected for infrequent primary contact recreation. Also protected for secondarycontact recreation where there is a low likelihood of ingestion of water or a low degree ofbodily contact with the water. Examples include, but are not limited to, wading, hunting, andfishing.

Class 3A - Protected for cold water species of game fish and other cold water aquatic life,including the necessary aquatic organisms in their food chain.

Class 4 - Protected for agricultural uses including irrigation of crops and stock watering.

Within the Forest Service boundary, Horse - Mill Creek, North Fork Mill Creek and Pack Creek arecurrently supporting all beneficial uses. Pack Creek from the confluence with Mill Creek to the ForestService boundary is not supporting the agricultural and cold water aquatic life beneficial uses due toexceedance of total dissolved solids, selenium and water temperature standards. Mill Creek, from theconfluence with the Colorado River to the Forest Service boundary is not supporting aquatic lifebeneficial uses due to exceedance of temperature and dissolved oxygen standards. A TMDL wasdeveloped for Mill Creek and accepted by the EPA. The TMDL lists improving the riparian overstoryon the BLM lands and a minimum flow below Sheley Dam as needed actions to improve water qualityfor this stream reach.

Municipal Watershed

The current Forest Plan for the Manti-La Sal NF predates the 1996 Safe Drinking Water Act andEPA's sole source aquifer program. As a result, the definition of a municipal watershed hasbroadened since the1986 Forest Plan. FSM 2542.05 defines a municipal supply watershed as onethat serves a public water system as defined in Public Law 93-523 (Safe Drinking Water Act); or asdefined in State safe drinking water regulations. The definition does not include communities servedby well or confined ground water unaffected by Forest Service activities. The 1996 Safe DrinkingWater Act (SDWA) Amendments established a new emphasis on preventing contamination problemsthrough source water protection and enhanced water system management. Formal agreementsapproved by the Chief of the Forest Service are appropriate only when intensified multiple-usemanagement fails to meet the needs of the water user and use restrictions are necessary.

Sole Source Aquifer:

West Slope WUI ProjectHydrology Report Joni Vanderbilt

The proposed West Slope WUI project is within the town of Moab's sole source aquifer designated bythe EPA for protection of drinking water supply. The intent of the designation is to protect bothsurface water and groundwater resources.

"The sole source aquifer program does not provide any direction about how the lands overlying adesignated aquifer might be managed nor are there any published guidelines about how EPA wouldevaluate a proposed activity or project.... It is the Forest Service's responsibility to ensure thatactivities implemented by the Forest or by permittees include appropriate best management and otherpractices to protect the groundwater classes and meet the associated standards (FSM 2543.04e)."Manti La Sal NF white paper (Katherine Foster, 2007).

Watershed Forest Plan Standards and Executive OrdersForest Plan Standards and Executive Orders - Applicable Forest Plan Direction for Soil and Water(USDA Forest Service 1986, p. III-4) includes the following: maintain satisfactory watershedconditions; provide favorable conditions of water flow (quality, quantity and timing); protect soil andwater productivity so that neither will be significantly or permanently impaired; and protect andenhance riparian areas including dependent resources.Executive Order 11988 of May, 1977 requires the Forest Service to provide leadership and takeaction to 1) minimize adverse impacts associated with occupation and modification of floodplains andreduce risk of flood loss; 2) minimize impacts of floods on human safety, health, and welfare; and 3)restore and preserve the natural and beneficial values served by floodplains. This executive order willbe addressed in the discussion of impacts to channel stability and flood potential.

Executive Order 11990 of May, 1977 requires the Forest Service to take action to minimizedestruction, loss, or degradation of wetlands and to preserve the natural and beneficial values ofwetlands. The discussion of impacts to water quality and flood potential and channel stability in thisreport includes the consideration of wetlands.

Environmental ConsequencesTo the extent possible, project design, site specific recommendations and the incorporation of SWCPsduring project implementation would mitigate concerns for watershed and water quality. However,differences between the alternatives are addressed in the following discussion.

Indirect and Direct Effects to Water Resources

Alternative 1This alternative does not mitigate the risk of wildfire in the proposed project area. Large scalewildfires have the potential of affecting watershed values by reducing infiltration and increasingrunoff in the short term and through loss of top soil and subsequent reduction in soilproductivity in the long term. A summary of uncontrolled wildfires in Region 4 of the ForestService that were assessed under the Burned Area Emergency Rehabilitation (BAER)Program shows that approximately 10% of acres burned in wildfires were classified asseverely burned (i.e., soils were detrimentally disturbed). Severely burned soils are lessresilient to intense rainstorms following fires leading to destabilized channels and to increasedsedimentation and/or erosion. This in turn can lead to damage of downstream irrigationsystems and reduce water quality for municipal supplies.

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Alternative 2

This alternative would reduce the risk of wildfire within the proposed project area and for theMill Creek Watershed. The reduced wildfire risk would last longest in pinyon-juniperdominated vegetation types. The benefit would be shorter lived in Gamble Oak dominatedvegetation types. Gamble Oak sprouts vigorously following mastication treatment reducing theeffectiveness of the treatment over time. Application of the herbicide tebuthiuron would extendthe longevity of the gamble oak treatments and is included in this alternative.

Tebuthiuron dissolves in water and is moderately mobile in soils (with the exception of soilswith heavy clay content). From field studies, it is not believed that tebuthiuron or itsdegradation products leach below the top 24 inches of soil. The herbicide is generally highlypersistent in soil. Reported field half-lives are over 15 months. Tebuthiuron is slightly topractically non-toxic to fish and other aquatic species (Extoxnet 1996). The label states thattebuthiuron should not be applied:

• in areas where the water table is shallow (5 feet or less) or adjacent to streams orlakes which are periodically flooded;

• where bedrock is continuously exposed or in areas of bedrock overlain by soils that areshallow or discontinuous;

• in areas of karst geology;

• to high shrink/swell soils,

• in protected groundwater recharge acres; or

• in areas where overland flow of water might move the chemical or soil containing thechemical from the treated areas.

Because of its water solubility and persistence in soils, Tebuthiuron could potentially leach intogroundwater or be incorporated into surface water during runoff events. In order to minimizethe potential risk to ground water and surface water quality as well as downstream drinkingwater uses, I recommend:

• Do not use tebuthiuron within 100 feet of perennial/intermittent or ephemeral streamchannels, ditches, springs or reservoirs.

There should be no direct or indirect effects to channels, floodplains and wetlands due toproject design and incorporation of recommendations and Soil and Water ConservationPractices (SWCP's). The potential risk to ground and surface water quality as well as todrinking water source areas is greater under this alternative than alternatives 1, 3 and 4.

Alternative 3

This alternative would reduce the risk of wildfire within the proposed project area and for theMill Creek Watershed, similarly to Alternative 2. The reduced wildfire risk would last longestin pinyon-juniper dominated vegetation types. Gamble Oak sprouts vigorously followingmastication treatment reducing the effectiveness of the treatment over time in these vegetationtypes.

This alternative would include additional treatment of drainages that could act as funnelsduring a wildfire. Where slopes permit, treatments would be done by mechanical masticationto within 50 feet of intermittent and perennial drainages. While hand removal of material wouldnot cause impacts to water resources, pile burning of the removed material can beproblematic. Because piles frequently burn at very hot temperatures for extended periods oftime the underlying soils can be severely burned. When this occurs, soils are sterilized,

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erosive and slow to recover vegetatively. If piles are located near to drainages the potential ofsediment mobilization and delivery into drainages is heightened. Therefore, I recommend:

• No pile burning within 100 feet of drainages and a greater distance if slopes are >30%or if treatment adjoins perennial streams. Material could be scattered or physicallyremoved from the site.

• Some slash could be left in the riparian area but some material may need to be pulledout (lopped and scattered) to avoid excessive loading of ground fuels in riparian areas.

This alternative would result in no direct or indirect effects to water quality, municipalwatersheds, channels, floodplains and wetlands due to project design and incorporation ofrecommendations and Soil and Water Conservation Practices (SWCP's).

Cumulative Effects: WatershedActivities that could combine with the action alternatives to result in a cumulative effect includeongoing livestock grazing, roads/trails and a multitude of recreation uses such as dispersedcamping, hiking, biking, ATVing, etc. Thinning of thick stands of brush could provide morelivestock movement through the area, resulting in spreading uses out away from parks andopenings. This would be a benefit to watershed values where livestock tend to congregatearound water sources and in parks. In addition, project design measures would not alter thecurrent patterns of recreation in the area so that there should not be a change from theexisting condition. Cumulative impacts to soils and watershed values are not anticipated withany of the action alternatives based on the above discussion.

ReferencesDissmeyer, G.E. (editor). 2000. Drinking Water from Forests and Grasslands: A Synthesis ofthe Scientific Literature. USDA Forest Service, Southern Research Station, GTR SRS-39.Available via http://www.srs.fs.usda.gov/pubs/gtr/gtr_srs039.

Dwire, K.A., and J.B. Kauffman. 2003. Fire and riparian ecosystems in landscapes of thewestern USA. Forest Ecology and Management, 178(2003): 61-74. Available viahttp://www.sciencedirect.com/

Utah Division of Water Quality. 2014. Utah's 2014 303(d) List of Waters.

Extoxnet. 1996. Herbicide facts forTebuthiuron. Extension Toxicology Network (main filesmaintained and archived at Oregon State University).

Prepared By Date

Joni Vanderbilt, Hydrologist

West Slope WUI ProjectHydrology Report Joni Vanderbilt

Soil and Water Conservation Practices (SWCP's)The Forest Service is the designated Water Quality Management Agency for National Forest Systemlands in Utah. A 1993 memorandum of understanding (MOU) between the Forest Service and theUtah Division of Water Quality defines the roles and responsibilities of each agency relative to waterquality management on National Forest System lands (MOU, 1993; UT NPS, 1998).

To comply with the antidegradation policy and State water quality standards, the Forest Service mustimplement or ensure the implementation of practices that maintain the current, high level of waterquality. These include practices in Forest Service Handbook 2509.22, Soil And Water ConservationPractices; State best management practices; or specialized, site-specific practices. All these types ofpractices are designed to fully protect and maintain water-related beneficial uses, and to prevent orminimize nonpoint source pollution (UT NPS, 1998).

Table 1 - SWCP's applicable to the planning phase of the proposed project

SWCP SWCP OBJECTIVE CONSIDERATIONS FOR IMPLEMENTATION

11.01 DETERMINATION OF CUMULATIVEWATERSHED EFFECTS - To determine thecumulative effects or impacts on beneficialwater uses by multiple land managementactivities.

See the appropriate section of the EA prepared for this project.

11.04 FLOODPLAIN ANALYSIS AND EVALUATION -To protect floodplain values and avoid, wherepossible, the long and short-term adverseimpacts to soil and water resources associatedwith the occupancy and modification offloodplains.

The SWCP states that a floodplain analysis and evaluation will be made when siteswithin floodplains are being considered for structures, developments, ormanagement activities. Environmental quality, ecological effects, and individualsafety and health will be considered.

Floodplains have not been mapped for the project area. All drainages have a flood-prone area adjacent to them. This flood-prone area would be included in the multi-distance buffer zones around all mapped drainages in the project area. Theproposed project should not facilitate additional structures or development in thefloodplains of streams within the project area.

11.05 WETLANDS ANALYSIS AND EVALUATION -To maintain wetlands function and avoidadverse soil and water resource impactsassociated with the destruction of modificationof wetlands.

The SWCP states that the Forest Service does not permit the implementation ofactivities and new construction in wetlands whenever there is a practical alternative.A wetland analysis and evaluation will be made prior to acquisition or exchange ofwetlands. Evaluation of proposed actions in wetlands will consider factors relevantto the proposal's effective on the survival and quality of the wetlands.

Wetlands associated with streams, springs, spring brooks, and reservoirs would beincluded in a multi-distance buffer zone - no herbicide within 100 feet; nomechanical treatment within 50 feet; no burn piles within 100 feet. No adverseeffects are expected.

11.14MANAGEMENT OF SNOW SURVEY SITES -To protect snow courses and related data sitedfrom effects by land management activities

The SWCP states that snow survey sites will be protected according to the terms ofthe MOU or special use permit issued to the NRCS. Consult with the NRCS ifadjacent activities might affect their value or site integrity.

There are no snow courses or SNOTEL sites the project area.13.07 PESTICIDE USE PLANNING - To incorporate

water quality and hydrologic considerations intoproject planning.

Note that this SWCP also applies toherbicides

The SWCP states that the pesticide use planning process will be used to identifysensitive areas, identify preventive measures and other mitigation measures, andincorporate hydrologic, water quality, and aquatic concerns.Sensitive areas have been identified and no-treatment buffer zones specified. SeeSWCP 11.05 and 13.10.

13.10 PESTICIDE SPILL CONTINGENCY PLANNING- To reduce contamination of water fromaccidental pesticide spills.Note that this SWCP also applies toherbicides

Contingencies for pesticide spill should be established as part of the projectimplementation plan or incorporated into the hazardous materials contingency plansper SWCP 11.07.

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SWCP SWCP OBJECTIVE CONSIDERATIONS FOR IMPLEMENTATION

18.02 FORMULATION OF FIRE PRESCRIPTIONS -To provide for soil and water resourceprotection while achieving managementobjectives through the use of prescribed fire.

The SWCP identifies the following prescription elements: fire weather, slope, aspect,soil moisture, and fuel moisture. These elements influence fire intensity and have adirect effect on whether a litter layer remains after burning and whether hydrophobiclayers develop. The amount of remaining litter and induced hydrophobicity cansignificantly affect erosion rates, water quality, and runoff volumes. Both theoptimum and tolerable limits for soil and water resource effects should beestablished.Slash piles should be constructed at least 100 feet from any drainage. Post-fire,contingency treatments likely will not be needed; the piles would be scatteredthroughout the project area and the burned patch under a pile is typically small (lessthan Iff x Iff).

Table 1 - SWCP's applicable to the implementation phase of the proposed project

SWCP SWCP OBJECTIVE CONSIDERATIONS FOR IMPLEMENTATION

13.02

SLOPE LIMITATIONS FOR TRACTOROPERATION - To reduce gully and sheet erosionand associated sediment production

Ground-based equipment operation will be limited to slopes of 30% or less.

13.03

TRACTOR OPERATION EXCLUDED FROMWETLANDS, BOGS, AND WET MEADOWS - Tolimit soil damage, turbidity, and sedimentproduction resulting from compaction, rutting,runoff concentration, and subsequent erosion.Note that this SWCP applies to all heavyequipment operations.

The SWCP states that application of the SWCP is mandatory for all vegetationmanipulation projects, including mining operations; exceptions must be specificallyaddressed in an environmental document. The agency project administrator orproject supervisor is responsible for identifying wetlands and meadows notpreviously recognized in the NEPA process and for following or developingmanagement controls to protect wetland and meadows. Protection of wetlands(mapped and unmapped) should be included in pre-work briefings.A 50 foot no mechanical treatment buffer zone will be flagged around springs,spring brooks, stream channels and reservoirs currently mapped in the projectarea. Similar buffer zones should be implemented for any springs and/or wetlandslocated during project implementation, See SWCP 13.08,13.12, and 14.20 fordescription of multi-distance buffer zones.

13.06

SOIL MOISTURE LIMITATIONS FOR TRACTOROPERATION - To minimize soil compaction,puddling, rutting, and gullying with resultantsediment production and loss of soil productivity.

Note that this SWCP applies to all heavyequipment operations.

Rutting will be used as an indicator of wet conditions. Should rutting occur thatmeets any of the following criteria, operations should be suspended until conditionsare more favorable: rutting in excess of one inch on gravel roads, 2 inches onnative surface roads and 4 inches in other work areas.

13.08 APPLY PESTICIDES ACCORDING TO LABELAND EPA REGISTRATION DIRECTIONS - Toavoid water contamination by complying with alllabel instructions and restrictions.

Note that this SWCP also applies to herbicides

See above for analysis of label restrictions, vulnerable site characteristics, and sitecharacteristics. The following buffer zones are for groundwater protection:

Leave a 100 foot untreated buffer on both sides of all mapped drainages andditches.

Leave a 100 foot untreated buffer around the springs, spring brooks, andreservoirs. Buffer zones should be flagged or otherwise marked as necessaryto aid in boundary location.

13.12

PROTECTION OF WATER, WETLANDS, ANDRIPARIAN AREAS DURING PESTICIDESPRAYING - To minimize the risk of a pesticideentering surface of subsurface waters or affectingriparian areas, wetlands, and other non-targetareas.Note that this SWCP applies to herbicides andto all application methods.

The only riparian area/wetland located in the project area during fieldreconnaissance is the spring and spring brook identified above.Leave a 100 foot untreated buffer on both sides of all mapped drainages and

ditches.

Leave a 100 foot untreated buffer around the springs, spring brooks, andreservoirs.

Buffer zones should be flagged or otherwise marked as necessary to aid inboundary location.

West Slope WUI ProjectHydrology Report Joni Vanderbilt

SWCP SWCP OBJECTIVE CONSIDERATIONS FOR IMPLEMENTATION

14.03

USE OF SALE AREA MAPS (SAMs) FORDESIGNATING SOIL AND WATER PROTECTIONNEEDS -To delineate the location of protectedareas and available water sources and insure theirrecognition, proper consideration, and protectionon the ground.Note that this SWCP also applies to fuelstreatment project maps..

No treatment buffer zones will be mapped and included on project treatment maps.

14.06

RIPARIAN AREA DESIGNATION - To minimizethe adverse effects on riparian areas withprescriptions that manage nearby logging andrelated land disturbance activities.Note that this SWCP applies to all heavyequipment operations.

Buffer zones are specified in SWCP 14.20

14.15

EROSION CONTROL ON SKID TRAILS - Toprotect water quality by minimizing erosion andsedimentation derived from skid trails.Note that this SWCP applied to any temporaryworking travelway.

To the extent possible, the "slashbusting" equipment should be operated overproject-created slash.

14.20

SLASH TREATMENT IN SENSITIVE AREAS - Toprotect water quality by protecting sensitivetributary areas from degradation which wouldresult from using mechanized equipment for slashdisposal.

Buffer zones for mechanical treatments:

Leave a 50 foot untreated buffer on both sides of all mapped drainages.Leave a 50 foot untreated buffer around the spring and spring brook.

Buffer zones for burn piles:Leave a 100 foot untreated buffer on both sides of all mapped drainages.Leave a 100 foot untreated buffer around the springs and spring brooks.

15.11

SERVICING AND REFUELING EQUIPMENT - Toprevent contamination of waters from accidentalspills of fuels, lubricants, bitumens, and otherharmful materials.Wofe that this SWCP applies in all areas whereheavy equipment is operated.

Refueling areas should be a minimum of 200 feet from perennial and intermittentstream channels, seeps and springs, wetlands, lakes and reservoirs, stock waterdevelopments, and other water features.

All heavy equipment and service vehicles should have a supply of absorbent andother cleanup materials on hand for initial containment of spills.All projects will adhere to the Hazardous Substance Spill Plan in case of accidents.