Mill Creek Master Plan
Main Report - Volume 1

1.01. The Mill Creek Project

Mill Creek, Washington, the project's official name, is located in southeastern Washington on Prospect Point Ridge. It lies at the transition between the foothills of the Blue Mountains and the Walla Walla Valley. The project boundary is adjacent to the city of Walla Walla, Washington (see plates 1-1 and 1-2). Mill Creek, Washington, has been referred to as the Mill Creek Flood Control Project since its beginnings. It was constructed by the U.S. Army Corps of Engineers (Corps) to protect the city of Walla Walla from the flooding of Mill Creek. This Federal project is composed of two major units: 1) Mill Creek Channel; and 2) the off-channel reservoir (Virgil B. Bennington Lake) and the lands referred to as the Mill Creek Project (MCP) in this report.

Photo 1-1. Oblique aerial view of MCP, with city of Walla Walla in background.

The Mill Creek Channel was primarily funded by the Federal Government, and was designed and built by the Corps. It runs through the city of Walla Walla, and was completed in 1948. It is now owned, operated, and maintained by the Mill Creek Flood Control Zone District (MCFCZD), a branch of Walla Walla County.

The MCP is owned by the Federal Government, and the Corps is responsible for the operation and maintenance of the project. It was completed in 1942, and has the capacity to protect the city of Walla Walla and surrounding lands up to a 140-year flood event. It contains 611.5 acres of fee-owned lands, and an additional 87.3 acres of easement lands. The MCP is the largest public open space in the Walla Walla Valley, and accounts for over one-third of the total of all public open spaces. Virgil B. Bennington Lake is the only public body of water within 28 miles of Walla Walla, and the only public lake within 45 miles. Large run-of-river lakes such as Lake Wallula, formed by McNary Dam, are referred to as bodies of water in this report. The MCP is located in a transition area between the forest areas of the Blue Mountains and the grasslands (see photo 1-2). The project contains recreation facilities at three locations: 1) Rooks Park; 2) Mill Creek Trail; and 3) the Bennington Lake Recreation Area (see photo 1-2). Currently, over 250,000 visitors enjoy MCP each year (see photos 1-3, 1-4, and 1-5).

Photo 1-2. Oblique aerial view of MCP.
The MCP is located in both grassland and riparian vegetation areas in the Walla Walla Valley,
and lies on the edge of the foothills of the Blue Mountains.
Water is diverted from Mill Creek into Virgil B. Bennington Lake.

Photo 1-3. Fishing on Virgil B. Bennington Lake. The lake provides primarily water-related recreation
(i.e., fishing, boating, swimming, and aesthetics).

Photo 1-4. Mill Creek Channel also provides water-oriented opportunities for visitors.

Photo 1-5. The MCP provides excellent habitat for a variety of wildlife,
in contrast to the surrounding agricultural fields.

1.02. Purpose

This report replaces the Master Plan for Mill Creek Reservoir, Design Memorandum 1, dated May 1961; Design Memorandum 2, dated February 1962; and Supplement 1 to Design Memorandum 2, dated 1 May 1965. It is necessary to update the Master Plan (MP) because of changes to Corps policies, as well as regional and project changes that have occurred since 1961. Volume 2, Technical Appendix,contains project and regional inventory and analysis, synthesis, and supporting data.

The MP is a guide for the use, development, and management of the land and water resources at MCP. All planning, management, and development actions should be consistent with the land classifications and resource objectives (RO's) presented in this plan. The MCMP will continue to be revised as Corps policy and regional or project conditions change. Volume 2, Supporting Data, Item 2, contains public laws, Corps policy, and guidance pertinent to the MCP.

1.03. Goals of the MP

The goals of the MP, as shown in figure 1-1, are to find the best possible RO's from a combination of public interests and desires (individuals, groups, and Federal, State, and local agencies), regional needs, resource capabilities and suitabilities, authorized project purposes, and Federal laws and directives.

1.04. Scope

The MP is a systematic organization of project goals and objectives, land use zoning, conceptual development plans, management priorities, and final recommendations. This was accomplished with an inventory and analysis of regional and project resources, as well as the application of Corps policy, public needs, and public desires. The MCP Final Environmental Impact Statement (EIS) was filed 12 December 1975. Considerable changes have taken place since 1975. After the Corps, North Pacific Division (CENPD) approval of this MP has been obtained, changes will be made in future updates to the project EIS.

This volume 1, Main Report, contains project land classifications and RO's. It also contains specific RO's and conceptual development plans for each management unit. The remainder of this volume consists of design criteria, future study recommendations, a summary, and conclusions.

The MP is comprised of two volumes. Volume 2, Technical Appendix, contains the regional and project inventory and analysis. It also contains the synthesis process, and the method by which land classifications and RO decisions were made.

The Master Planning process includes the MP as well as the Operational Management Plan (OMP), which will detail the method for achieving the management goals and objectives of the MP (see Engineering Regulation 1130-2-400 for details).

1.05. Coordination

All development will be coordinated with appropriate Federal, State, and local agencies throughout the MP process.

The MCP contains one-third of the public lands open for recreation in the Walla Walla Valley, and provides important wildlife habitat. The MCP is along the Mill Creek Recreation Trail and the proposed Walla Walla Trail (a county and city proposal). Coordination will ensure that recreation demands can be met, and that resource degradation and conflicts are minimized. Development will be planned, within resource capacities, for each individual site.

The Corps will continue to coordinate the MP and its revisions with all appropriate agencies and the public.

1.06. Planning Process

The planning process used for the MP update is shown in figure 1-2. The process matches public desires and regional needs with project resource capabilities and potentials.

The following is a brief overview of the steps involved in the planning process, as shown in figure 1-2:

• Step 1: Regional and project resources were inventoried and analyzed. This analysis defined the regional area of study, and included ecological, cultural, and aesthetic factors.
• Step 2: Preliminary land use and RO's were developed. Land use identifies the primary activity for each management unit, while RO's are specific statements that clearly identify the selected option(s) for project lands. The RO's are used to guide the use, design, development, and management of the project and its resources. For a detailed description of this step, see volume 2, section 4, Synthesis.
• Step 3: Government agencies, as well as the public, reviewed preliminary land use and RO's. The public and agency comments were analyzed and incorporated in the draft land classification plan and RO's (see sections 3 and 4 of this volume).
• Step 4: The RO's and conceptual development plans were formulated through an interdisciplinary team effort for each management unit, based on the synthesis of the regional and project factors, as well as agency and public input.
• Step 5: The March 1993 draft was sent out for review and comment by the Corps, Walla Walla District (CENPW). Comments were incorporated by an interdivision team in this plan.
• Step 6: This final report is sent to CENPD for approval.
• Step 7: Approval granted by CENPD on 22 May 1995. The MP will be updated or revised as necessary.

Section 2 - Influencing and Constraining Factors

2.01. General

This section is a summary of the important environmental, cultural, and aesthetic influences and constraining factors that determine the project RO's, land use plan, management unit RO's, and development plans. Also included in this section are comments and involvement of other agencies and the public. Photo 2-1 shows the city of Walla Walla, Washington, and its environs.

Photo 2-1. Walla Walla, Washington. The city and its environs have a current population of 37,000, and is adjacent to MCP.
The population is forecasted to grow at a rate higher than the State of Washington.

2.02. Summary of Regional and Project Factors and analysis

Figure 2-1 contains a listing of the important regional and project ecological, cultural, and aesthetic factors (see volume 2 for definitions that influence the MCP). A summary of regional factors is discussed in paragraph 2.03., Summary of Regional Factors and Analysis, while MCP factors are discussed in paragraph 2.04., Summary of Project Factors and Analysis.

Figure 2-1. Regional and Project Factors

2.03. Summary of Regional Factors and Analysis

a. Ecological Factors.

(1) Physiography.

Because MCP is located near the border of both the Palouse and Blue Mountain Physiographic Provinces, it contains a wide variety of ecological features in a relatively small area. This provides the public with high visual resource quality and a wide diversity of landforms, wildlife, and vegetation.

(2) Geology.

Minor tectonic activity is happening in the vicinity of MCP and is recorded as light earthquakes on local seismographs. These are not considered a serious threat to the MCP.

(3) Soils.

The soils in the region are extremely varied; from rock outcroppings to deep, productive soils. The MCP contains both extremes, both on, or adjacent to, the project.

(4) Hydrologic Basins.

Water within the region has become a serious issue. The MCP is located over a developed aquifer, and has the potential to recharge the aquifer. Currently, all surface water is closed to appropriation.

(5) Limnology.

Overall, the regional water quality is good. Water quality degradation in the Walla Walla Basin is exacerbated by irrigation withdrawal, as well as the lack of base stream flows caused by groundwater depletion and soil erosion. Mill Creek Basin provides good water quality to the project, but the quality deteriorates downstream, primarily because of irrigation withdrawals and point-source pollution resulting from municipal sewage, cannery waste, and stormwater runoff.

(6) Climate.

Regional climate influences the project throughout the year. Seasonal climatic patterns provide heavy winter precipitation, and hot dry summers. The project is required for flood control because of heavy precipitation and runoff in the Blue Mountains. During heavy runoff years, Virgil B. Bennington Lake can be kept at conservation elevation for a longer period of time in the spring (1,205 feet mean sea level), until June or early July. High temperatures during the summer months encourage visitor use and, conversely, below normal temperatures and above normal precipitation discourage visitor use during the summer months. The regional climate is such that water is a critical resource for irrigation, recreation, fisheries, and vegetation.

(7) Air Quality.

The major air quality factors that influence MCP are visibility and odors. When the wind direction comes from the west, undesirable odors from the Wallula area may be detected at MCP. Up to the present, however, these are not consistent enough to create a problem.

(8) Vegetation.

The MCP is located in an ecotone, which offers a mosaic of vegetation patterns that support wildlife, fisheries, recreation, and scenic quality.

(9) Wildlife.

The MCP is located at the juncture of three physiographic sections and four vegetational zones. The resulting variety is important to many different types of wildlife, including neotropical migratory birds and other migratory species.

(10) Fish.

The recent listing of migratory salmon species under the Endangered Species Act (ESA) is having impacts on the region, but not on the MCP. The MCP will probably be affected if the bull trout of Mill Creek are listed under the ESA. As of September 1, 1993, the U.S. Fish and Wildlife Service (USFWS) has given a positive response to the proposal for listing the bull trout as an endangered species throughout its range. The USFWS has 1 year to collect information and officially list where critical habitat will be designated.

b. Cultural Factors.

(1) Market Area (MA).

The primary MA for Mill Creek is composed of the city of Walla Walla and the Walla Walla Valley, with 50,000 residents. The primary MA will determine the present and future demands on MCP. Over 90 percent of the visitors at MCP originate from the primary MA. The economy, population, and access of the primary MA affect current and future visitation, as well as other needs at MCP.

(2) Access.

The MCP is served by two major highways in the Walla Walla Valley. U.S. Highway 12 runs east and west, and connects the city of Walla Walla with the Tri-Cities of Washington and Lewiston, Idaho. Oregon State Highway 11/Washington State Highway 125 runs north and south from the city of Walla Walla. These highways provide MCP with excellent visitor access from the entire primary MA (see photo 2-2).

(3) Demographics.

Recently, the MCP primary Ma has been experiencing a population rate increase that is twice the rate of increase in Walla Walla County and the State of Washington. This is a 29-percent growth increase in the next 12 years, which will place additional pressure on MCP.

(4) Economy.

Currently, the primary MA has a per capita income below both state and national rates. This will place additional pressure on local parks and recreation areas, since they are nearby and inexpensive. The county is changing from a primarily agriculture-based economy to a more varied and stable one. In fact, locally, agriculture is ranked below service/finance, government, manufacturing, and trade. The stability of the Walla Walla economy will ensure population and economic growth in the area, and this will cause additional pressures on resources at MCP.

(5) Land Ownership.

The large tracts of public-owned lands in the region partly attribute to lowering the demand on MCP.

(6) Land Use and Cover.

Current land use patterns are expected to remain stable in the future, except for urban growth (see photo 2-3).

(7) Regional Outdoor Recreation.

Virgil B. Bennington Lake is the only public body of water within 28 miles of the city of Walla Walla. The MCP's lake, creek, foothills setting, recreation facilities, and close proximity to Walla Walla attracts high visitation. Because of the projected population growth in the Walla Walla/MCP area, recreational opportunities and demand on day-use facilities will continue to increase dramatically in the future.

c. Aesthetic Factors.

The MCP is an area sensitive to aesthetic impacts (see photo 2-4). Three major factors account for a visually sensitive area. The first is that MCP is located in a transition zone between two major landform types: the Blue Mountains and the Palouse. This transition zone is an area where human senses are heightened. Second, surrounding agricultural land use, with very low monoculture vegetation type and gentle slopes, has a low visual absorption capacity. This lack of ability to absorb the visual impacts of developments requires sensitive development criteria. Third, recreation visitors expect high scenic quality on public lands. These factors create a need for a visual management plan that includes methods of sensitive development and management recommendations.

2.04. Summary of Project Factors and Analysis

a. Ecological Factors.

(1) Hydrology (Mill Creek Basin).

Because runoff is low in the summer and the demand for water is extremely high, Mill Creek's low runoff years can critically affect lake levels in the summer months. A lower lake level affects recreation, water quality, wildlife habitat, and fisheries. Lower lake level elevations reduce the area and volume of the lake, and this reduces the area available for boating and increases the water temperature, adversely affecting both water quality and fisheries. (See volume 2, paragraph 3.03.e., Water Resources Facilities and Operations, for a further discussion of this subject.)

(2) Limnology.

Due to the occasional occurrences of low water quality conditions resulting from anoxia (low amounts of oxygen), hydrogen sulfide production, excessive turbidity, and microorganisms, there is some impact to the existing beneficial uses of Virgil B. Bennington Lake. Although there never has been production or spawning habitat in the lake, trout are restocked annually through a Washington Department of Wildlife (WDW) program. The value of Virgil B. Bennington Lake as trout habitat could be increased by maintaining a higher conservation pool, providing refill in the autumn, and doing substrate manipulations. The existing constraints on pool elevation due to dam integrity problems and the lack of available water (see photo 2-5) during the summer result in a shallow pond that is subject to high temperatures and increased turbidity caused by wave action on bottom sediments. Low dissolved oxygen levels increase, reducing the water quality for fish, while a lack of flow in Mill Creek Channel during the summer months strands pools of low quality water below the dissipation structures (see photo 2-6). The lake is unique (for a shallow lake), in terms of water quality, because of its tendency to stratify thermally and because of the way it is filled. Therefore, the lake's responses to various management practices, or to natural alterations, may not approximate those of more typical lakes and reservoirs.

(3) Climate.

The MCP was envisioned and constructed because of the damaging effects of climate on the local area. Climate also has an effect on water control operations and recreational activities at Virgil B. Bennington Lake. High temperatures and/or low precipitation during the summer recreation season attracts visitors to the project but, due to evaporation, also lowers the elevation of the lake. Low precipitation during November through February results in below normal spring snowmelt runoff. This, in turn, affects the length of time the lake level can be maintained at elevation 1205 during the summer (see volume 2, paragraph 3.03.e., Water Resources Facilities and Operations).

(4) Air Quality.

The air quality in the Walla Walla area is generally good, primarily because of adequate ventilation in the Walla Walla Valley and the lack of intensive urbanization. Air quality problems with suspended particulates usually occur during the summer season, and may be attributed to agricultural activities (i.e., tillage, harvesting, and field burning), thermal atmospheric inversions, and winds. Smoke from inefficient woodstoves poses a problem in the cold winter months during temperature inversions. Carbon monoxide levels are minimal and are concentrated in the central business district, Eastgate, and Plaza Way during peak traffic hours.

(5) Land Cover and Vegetation.

Differences in vegetation were identified through a classification of vegetation. The three main types found were "terrestrial," "riparian," and "wetland" at MCP. To a large extent, these differences determine wildlife niches, habitats, and associated values. Nearly 70 percent of the project is classified as upland vegetation, with upland field (U-F) making up 53 percent of the project. The remaining portions of the project consist of riparian (7.6 percent), wetlands (6.7 percent), lacustrine (7 percent), riverine (2.1 percent), and urban, or built up (9.2 percent). There are 6 major classifications, 19 subclasses, and a total of 118 separate areas on the project. The MCP has a variety of vegetation types in a relatively small area. This contributes to good wildlife habitat, recreation, and visual quality. Some of the vegetation types are made up of monoculture species (one type of plant). In the future, the creation of greater species diversity would further improve wildlife habitat. The 63-acre land parcel purchased in 1991 (as part of the Lower Snake River Fish and Wildlife Compensation Plan) has been seeded in native grasses, and is in the planning stages of wildlife planting.

(6) Wildlife.

Wildlife habitat development is limited by ecological, cultural, and economic constraints. The dry climate retards the establishment and variety of plants, but the fertile soils and gently-sloping topography provide considerable opportunities for development.

Many habitat improvements were made by WDW in the 1950's, under a cooperative agreement. The vegetation planted then has provided food and cover for a wide variety of birds and mammals. These initial habitat improvements, however, are limited in plant species composition and age class. In addition, raising and lowering the elevation of the lake has resulted in a manipulating force that has changed the structure and composition of vegetation adjacent to the lake and diversion channel. The process of filling the lake (raising the water elevation) can be used as a management tool to modify areas away from water sources. These areas are presently limited to the introduced species adaptable to dry-land sites. Vegetation management on these elevated sites has been limited to manipulation through mechanical alteration. Selective control has been achieved through chemical eradication of undesirable species, partially to comply with the requirements of the local county weed board.

Damsite rehabilitation in the mid 1980's provided opportunities for wildlife habitat improvements. During the mid 1980's, a large-scale habitat improvement effort was undertaken. This effort involved the planting of approximately 45,000 trees and shrubs, including approximately 4,000 willow and cottonwood trees, randomly located in clumps along a proposed shoreline (elevation 1212). A subsequent decision resulted in a lower shoreline (elevation 1205).

Volume 2, paragraph 3.03.h., Wildlife Habitat Improvements, discusses the location and configuration of these plantings (see plate 3-16 in volume 2, section 3). A review of the existing vegetation cover characteristics (see plate 3-6 in volume 2, section 3) and the dam rehabilitation wildlife planting clearly illustrates the high wildlife habitat value that will develop in the next 5 to 10 years. This improvement is timely in its relation to overall project wildlife value. Earlier plants have matured to a point where their actual vertical and horizontal cover may not meet the needs of many wildlife species (e.g., as trees mature, groundcover may become sparse). The dam rehabilitation wildlife plantings will bridge the gap in species age composition, and greatly increase the interspersion and juxtaposition of habitats.

The forebay area is the area above Diversion Dam. It contains important wetland and riparian habitat. A considerable opportunity exists to improve this habitat through water elevation manipulation. This area could become an important waterfowl and furbearer habitat, and provide opportunity for both passive and consumptive use.

(7) Fish.

The fish habitat in Mill Creek is presently limited by a number of factors. These factors include barriers to upstream migration of steelhead and other trout; habitat degradation caused by streambank erosion and flash flows; a lack of instream cover and riparian vegetation below the diversion dam; high temperatures; low dissolved oxygen levels; and low, or zero, flows in the concrete channel (USFWS, 1984).

Both high and low flows can degrade habitat quality. Mill Creek has been greatly impacted by the effects of irrigation withdrawals. These withdrawals result in a zero flow below the Diversion Works (RM 10.5) after the first part of May or June each year (refer to photo 2-6). The concrete channel through the city provides passage for juveniles to downstream rearing habitat when sufficient flows are available.

The water quality in Mill Creek degrades steadily as it flows downstream from Kooskooskie (RM 21.5). Summer water temperatures may increase from 65°F to 79°F by the time the creek reaches Diversion Dam (RM 11.5). Temperatures greater than 65°F are considered stressful to salmonids. Dissolved oxygen remains at saturation levels until the creek passes the city sewage treatment plant (RM 5.5). Other water quality parameters are generally uniform in the upper and middle reaches, and are indicative of a clean stream (refer to volume 2, paragraph 3.02.e., Limnology).

(8) Mill Creek After completion of the Mill Creek Flood Control Project.

The sections of Mill Creek that flow through project lands include the channel and forebay area. The channel is designed to carry high flows during flood events, and lacks a low-flow channel. Boulders were added in 1986 to mitigate the impacts of flood channel maintenance and enhance fish habitat, but the uniform depth of the channel limits its aquatic value (USACE, 1986). During low-flow periods, the water becomes very shallow, and is too warm to support fish life. Channel weirs also limit fish movement during low-flow periods.

The forebay area is slightly impounded. This reduces flows, and allows silt and gravel to settle and accumulate. The excavation necessary to maintain flood-control capability periodically alters the stream channel. High winter and spring flows, following maintenance excavation, scour out new pools and channels, and may increase the carrying capacity of the stream (see photo 2-7). This constant siltation and frequent dredging limits functional habitat development, as well as the natural ecological succession of vegetation and organisms in the stream channel.

(9) Virgil B. Bennington Lake.

Virgil B. Bennington Lake's value as a fishery resource is limited by poor water quality, circulation, and supply, as well as by substrate value. Organically rich bottom sediments presently reduce water quality, especially during periods of lake stratification, by eliminating or reducing oxygen supply at lower depths (see volume 2, paragraph 3.02.e, Limnology). The existing silt-organic substrate limits benthic organisms to burrowing varieties, and does not provide cover for small fish and crayfish. The fluctuating water level (due to dam seepage and evaporation) reduces the lake level during the growing season, thus hampering the establishment of littoral rooted vegetation.

(10) The ESA Listing of Bull Trout.

If bull trout are listed under the ESA, any actions proposed for the project would need to be carefully considered to determine what, if any, effect the action might have on the bull trout. These actions could include the operation and maintenance of project water and recreation if the local population of bull trout is listed as threatened or endangered. The USFWS received petitions to list the bull trout in October 1992. In the Federal Register notice dated May 17, 1993, USFWS determined that substantial information existed to conduct a status review of the bull trout. The USFWS had 12 months from the date of the petition to publish their findings. In September 1993, the USFWS findings indicated that a positive listing action for endangered status was warranted, with a notice published in the Federal Register that includes the text for the proposed regulation. Upon further data and information collection and analysis, a determination must be made at the end of another 12-month period on whether to adopt or withdraw the regulation.

b. Cultural Factors.

(1) Archaeological and Historical.

(a) General.

To date, no known prehistoric, or historic, sites or events have been located on project lands, except for the close proximity of the Nez Perce Trail, the Fort Walla Walla Timber Reserve, and the emergency water reservoir for Walla Walla Air Base. Additionally, the age of the project's facilities (50 years) may have cultural importance.

(b) Future Findings.

If cultural resources are found at MCP in the future, they will be assessed for significance. Depending upon the significance of the resource, as well as its location, proposed project developments may have to be temporarily stopped and/or modified to address cultural resource concerns.

(2) History of Mill Creek Flood Control Project.

The MCP was 50 years old in 1992, and the concrete channel portion will be 50 years old in 1998. The entire project has served the Walla Walla Valley well since its beginnings over 70 years ago. The Corps should inform the public about the project's history through interpretive displays. The recent name change of Mill Creek Lake to Virgil B. Bennington Lake and the name of the total project needs to be clarified throughout the Corps, as well as with the public.

(3) Land Status.

(a) The MCP.

1. Boundaries/Monumentation.

The monumentation on the MCP boundary serves both the project and the public by identifying MCP lands. There are 11,000 feet of fee title lands that still need to be monumented.

2. Ownership.

The lands purchased by the Corps in the early 1940's were acquired for flood control purposes only. Over 194 acres were disposed of in 1955, based again on requirements for flood control use only. The lands outside the lake (elevation 1265) were disposed of because they were no longer needed for flood control. There are small areas outside the current project boundary that would be flooded at freeboard elevation 1270. Since that time, the Corps has managed the MCP for recreation and fish and wildlife habitat, as well as for flood control. The original acquisition would have better served these purposes, because they would provide additional wildlife habitat and recreational opportunities for the public. The Corps has management rights and responsibilities on these U.S. Government fee-owned lands.

3. Disposals.

There are no land disposals pending. Large disposals in the past would have provided a larger land base for wildlife and recreation opportunities today.

(b) Adjacent Lands.

The lands that surround the project are highly productive, agricultural lands. They are large tracts, except for the area around Reservoir Road. The county's comprehensive plan reflects this, and promotes continued agricultural use. In 1992, Walla Walla County, at the urging of private land owners, changed the minimum lot size from 20 acres to 160 acres. The 20-acre size had allowed residential development within ½ mile of the project. The high minimum acreage will restrict development near the project. The county is currently updating its zoning to reflect the plan.

(4) Transportation.

The MCP has an excellent system of roads and trails that serve both project operations and the public. A road is never farther than ¼ mile from any part of the project lands. The existing service roads provide excellent service, as well as emergency access, to the project lands. A small portion of the shorelines are accessible by road. The short length of the boat ramp limits boating when the lake elevation falls below 1200 feet (usually around the first part of July). A trail system closer to the lake would provide improved access for recreational activities such as shore fishing. Currently, access to the lake is dangerous for the elderly, and is difficult for other visitors. No access is available to the lake at all for persons with disabilities.

(5) Water Resource Facilities and Operations.

(a) Analysis of Water Resource Facilities.

The water resources facility on the project is designed to protect the city of Walla Walla up to a 140-year flood event. The only major problem is the slow seepage of the lake which, at this time, adds to a drop in the elevation of the lake during the summer. Since the facilities were constructed over 50 years ago, they have been improved and modified over time. If the seepage problem is corrected in the future, a higher conservation lake elevation could be maintained.

(b) Analysis of Flood Control Operations.

Low runoff seasons will affect the following: 1) water quality; 2) sport fishing, both at Virgil B. Bennington Lake and in Mill Creek; 3) irrigation; and 4) the Walla Walla Municipal water supply. During a drought year, downstream water rights have priority over the diversion of water from Mill Creek into Virgil B. Bennington Lake. As a result, the length of time that the conservation pool remains near elevation 1205 would be significantly shorter throughout the spring and early summer than during above average runoff seasons. In addition, on an average annual basis, evaporation alone would result in approximately 4 feet of reservoir drawdown (refer to volume 2, paragraph 3.02.f., Climate, and table 3-16, Monthly Evaporation.

(6) Building Facilities.

Some project buildings were constructed in 1939 for purposes other than their current use. The buildings do not meet current building standards, which include electrical, insulation, and mechanical. From an aesthetic viewpoint, the buildings on the project are architecturally different and offer no continuity of form. There needs to be an evaluation of project structures based on energy, usage, and aesthetics.

(7) Fencing.

The fences on the project boundary provide identification of project property. Before the boundaries were fenced, agricultural crop production has encroached onto MCP lands. Currently, many fences are damaged. The unfenced project boundary may have a problem with agricultural encroachment. The project boundary that crosses Mill Creek should be fenced to identify Government-owned property for operational and recreational activities in the forebay area. The fencing located within MCP provides security, guidance, and barriers. The high, chain-link security fence around the project office is unsightly, and alternatives should be explored.

(8) Wildlife Habitat Improvements.

When the project lands were purchased in the 1940's, all the lands south of the bluff were in wheat production. The development and management of wildlife habitats at MCP was initially conducted by utilizing a cooperative agreement type of license with the Washington Department of Game (WDG). This license was in effect for approximately 17 years (from 1964 to 10 April 1981). The initiation of intensive wildlife management activities began in the mid-1950's, when WDG established the original meadow, food plot, and tree-shrub plantings (WDW, 1953 and 1975).

The Corps, Walla Walla District, began active wildlife-habitat management with the development of additional tree and shrub habitat areas on the project between December 1982 and February 1985. These plantings were conducted as compensation for plants destroyed by the 1980 to 1982 Mill Creek Dam and Outlet Canal Rehabilitation Project.

The purchase of 61.8 acres adjacent to MCP, as Element X credit for the Lower Snake River Compensation Plan, was completed in Fiscal Year 1991. The wildlife-habitat developments planned for this area will include enhanced herbaceous ground cover, two gallinaceous guzzlers, two wildlife food plots, and four tree and shrub plots. These wildlife-habitat developments, scheduled for completion by October 1996, will greatly enhance the wildlife habitat and hunting recreational values provided by MCP. These established developments are shown in volume 2, plate 3-6, Land Cover and Vegetation; and plate 3-16, Fish and Wildlife Developments.

Additional wildlife habitat improvements should be contemplated for MCP. The enhancement of the riparian and wetland habitats at the forebay, and at the location of the diversion inflow to the lake, would greatly improve the habitat for riparian and wetland species. Many of the older tree and shrub plantings by WDW are dominated by Russian Olive. Replacement of some of the Russian Olive and expansion of these sites will improve the wildlife utilization of these older habitat developments. Establishment of additional wildlife food plots, by using strips of annual agricultural crops, will improve the brood habitat for gallinaceous birds and increase the availability of winter food.

(9) Fish Habitat Improvements.

Although WDW has stocked rainbow trout in Mill Creek and Virgil B. Bennington Lake for a number of years, habitat improvements are few. As mitigation for vegetation removal in the Mill Creek Channel for maintaining flood capacity in 1986, the Corps installed a limited number of boulders for fish cover at the request of WDW. However, many other opportunities exist to improve fisheries quality through habitat improvements and project operations. Photo 2-8 is a newspaper advertisement for the Annual Kids Fishing Derby at Virgil B. Bennington Lake.

(10) Recreation Facilities.

The MCP provides recreational opportunities for over 250,000 visitors each year. The facilities have increased and improved over the last 40 years, but there are many improvements that can be made to better serve the public and still meet the resource capacity.

The project is relatively undeveloped for recreation. Only 24 acres (4 percent) of the total land are specifically used for developed recreational facilities. There is overcrowding at Rooks Park, and the facilities at the lake are underdeveloped (see photo 2-9). There is also a great demand for improved day-use facilities and access to the lake area. Access to the lake shore is difficult for the elderly and/or persons with disabilities, and is considered a safety problem. There are no facilities for picnicking at the lake. The boat ramp only extends to elevation 1200, but the lake is usually below 1200 feet by the first part of July. Parasite problems in the lake waters limit its use for swimming.

(11) Visitation.

(a) Method.

The current method of estimating visitor usage will be improved with the upcoming Visitation Estimation and Reporting System (VERS) survey. There is, however, more information needed for forecasting. The areas that need more, or updated, information are: visitor origin, breaking up the "other" category, working with correlation to influencing factors, and improving seasonal activities. Refer to volume 2, section 3, paragraph 3.03.k.; and section 8, of this report for further discussion and recommendations.

(b) Forecast.

Using projection 4 data [see volume 2, paragraph 3.03.k.(7)(c)4.], an increase in facilities must be in direct correlation with the demand, or there will be a change in visitor experience (see volume 2, section 2, table 3-42 and figure 2-23). There must be a 38-percent change in the type of facilities at the lake area and the levee trails, and a 48-percent increase in the type of activities available at Rooks Park, to keep visitor experience the same. At some point, the resource will be impacted if this demand is not managed properly and new facilities are not provided.

Photo 2-10 shows MCP in use as an environmental education area.

(12) Recreation Carrying Capacity.

Recreation carrying capacity is a guide for understanding the current, and projected, use of certain activities. The projected growth in all of these recreation activities will continue to place pressure on the available resources. Volume 2, table 3-53, summarizes the densities for each activity, as well as the location of current use.

Non-motorized boating and boat fishing are activities that have reached social capacity. The demand is probably much higher than people's tolerance, and the current density may be unacceptable during heavy use. Boat launching is adequate, except that the ramp needs to be extended to allow launches at lower lake elevations. Shoreline fishing is in the upper density level, especially when considering the poor access and the lack of developed facilities for shoreline fishing. Camping facilities are possible at a few locations, but the size needs to be addressed and the social capacity must be considered. Swimming is like shoreline fishing in that there is great demand, but no formal facilities. Trail activities are growing, and are most dense at the Mill Creek Trail area. The lack of information on use at the other sites is a problem. Picnicking at the lake occurs in spite of the fact that there are no formal facilities. Rooks Park provides a low-density picnic experience, but this facility could triple and still provide a low-density experience.

(13) Aesthetic Factors.

(See Regional).

2.05. Other Agencies Involved

Other Federal, State, and local agencies were invited to participate in the planning process and review of a brochure that included preliminary RO's and a land classification map. They are also invited to review this draft MP, and their comments will be incorporated. The following is a list of agencies that were contacted with the brochure. Those agencies with a plus (+) returned comments on the brochure, while the agencies that returned comments on volumes 1 and 2 will be marked with an asterisk(*).

• Federal Agencies
  Fish and Wildlife Service
  Forest Service - Walla Walla District Office
  National Park Service
  National Park Service--Whitman Mission National Historical Site
  Soil Conservation Service--Walla Walla
  Veterans Affairs Department--Veterans Hospital Historian
• Washington Agencies
  Department of Wildlife
  Department of Fisheries
  Department of Parks and Recreation
  Department of Natural Resources
  Department of Ecology
  Department of Transportation
  Department of Health and Welfare
  Department of Lands
  Department of Water Resources
  Division of Budget Policy Planning and Coordination - City and county
  Historical Society
  +Walla Walla Community College
• Walla Walla County
  County Commissioners
  +Regional Planning Department
  Mill Creek Flood Control Zone District
  Health Department
• City of Walla Walla
  Park and Recreation Department
  Fort Walla Walla Historian
  Planning and Zoning

2.05. Public Involvement

a. Past Public Input.

On November 24, 1987, the Corps announced that, in order to protect Mill Creek Dam from damage resulting from seepage problems, the operating criteria would change, resulting in the absence of a lake. The Corps was also studying a solution involving placing a liner under the lake, but this was later determined not to be economically feasible. The Corps held a public meeting on December 10, 1987, at Walla Walla Community College. The problems and possible solutions were outlined at this meeting, and many comments that could be used in the MP were solicited. The public responded with a petition (with 932 signatures) requesting that the lake be refilled, but the petition was never submitted to the Corps until the MP brochure described in the following paragraph was sent out. The lake was not filled in 1989 and 1990. A later decision, made by higher authority, to operate the project as before resulted in refilling the lake in 1991.

b. Brochure--Public Input.

Initially, a brochure was prepared that listed the project RO's and land classifications. Over 500 brochures were mailed to the public. They were also placed in local libraries, sporting good stores, and department stores. An article in the local paper, the Walla Walla Union Bulletin, also informed the public of the brochure. Approximately 30 comments were received. A summary of this draft MP will also be available to interested individuals and groups, and copies of the draft will be available as well. The following organizations submitted comments on the brochure:

+ National Audobon Society--Blue Mountain Chapter

+ Walla Walla 2020

+ Tri-State Steelheaders

Chamber of Commerce

The following is a general listing of the comments submitted:

[Other comments received discussed an individual or single purpose (i.e., restrict hunting, build a white-water kayak course, buy more land, pick up litter, etc.]

The general concept presented was to protect the natural aspect of the lake and surrounding project and to enhance the fish and wildlife habitat for the following:

• Better fishing
• Increased hunting (less restrictions)
• Protection of wildlife habitat
• Enhance the site for natural and interpretive studies
• Leave the area natural

Most people wanted the lake left as it is, with the exception of providing better access to some areas. They wanted a natural setting to visit without having to make a long trip. It was the general consensus that the existing picnic/day-use facilities were adequate and the addition of small items (e.g., picnic tables, improved parking, stairways to the lake, etc.) was acceptable. Overall, they seemed to feel that the Corps is doing a good job of managing the project, and the decision to refill the lake was appropriate.

One important comment is that there was originally a great deal of concern about the draining of the lake. Since the Corps never received the local petition with 932 signatures, there was the false belief that residents were indifferent to draining the lake. The resounding support from the local community is that people appreciate the MCP and want it protected. It was also mentioned that more land should be purchased around the lake to enhance an already excellent recreational and natural area.

3.01. General

Project RO's are clearly written statements that are specific to a project or project area. They specify the selected option(s) for resource use, development, and management. They must be consistent with authorized project purposes, Federal laws and directives, regional needs, resource capabilities, and expressed public desires. Formulation and establishment of objectives for each civil works project is required by Engineer Regulation (ER) 1130-2-435, dated December 1987. This is part of the planning process outlined in section 1 of this MP.

Project and unit objectives serve to guide the design, development, use, and management of the project and its resources. Project RO's are presented in this section. The RO's for each separate management unit are presented in section 5 of this volume.

The following list contains RO's that reflect input from the public and Government agencies, based on an analysis of the resources at both project and regional levels. These RO's were listed by number, and grouped under the categories of Operations, Recreation, Wildlife and Fish, and Visual Resources. Figure 3-1 indicates the way in which each management unit can meet the project RO's. The project RO's will be updated as needed throughout the MP process.

3.02. Project RO's

a. Project RO Number 1—Project Operations.

Continue to safely and efficiently operate and maintain MCP to provide flood control for the protection of the city of Walla Walla and environs, as authorized in public law. Photo 3-1 shows flood damage in Walla Walla, Washington.

(1) Rationale.

The MCP is Federally authorized for flood control to protect the city of Walla Walla and environs.

(2) Implementation.

The project will continue to operate for flood control, as authorized by Federal law and as described in Flood Control Manual - Mill Creek Flood Control Project, in cooperation with the Mill Creek Flood Control Zone District (Walla Walla County). Changes as a result of this MP will be incorporated into the Flood Control Manual. The operation for flood control will take into consideration other project resources (wildlife, recreation, etc.), while still meeting the needs for flood control.

b. Project RO Number 2--Replacement/Relocation/Upgrade of Existing Facilities.

Assure that all facilities meet Federal, State, and local design, health, safety, and environmental standards.

(1) Rationale.

The MCP was constructed over 50 years ago. Many facilities are between 30 and 50 years old, and do not meet state and local health, safety, and environmental requirements. The replacement of these deteriorated facilities is essential. The need for sound facilities is critical because of additional visitor use and changing standards i.e., access for persons with disabilities and the elderly). The project office (see photo 3-2 and the lake recreation area need the most attention. Their site layouts do not meet current safety regulations and guidelines. Major redesign of the site layout may be necessary to alleviate safety problems and bring the layout to current standards.

(2) Implementation.

The replacement/relocation/upgrade (see photo 3-3) will include, but is not limited to, the following:

• project office
• maintenance/storage buildings
• road realignments
• boat ramp
• paving parking lots
• stripping parking lots

Replacement/relocation/upgrade will be budgeted under the operations and maintenance budget.

c. Project RO Number 3--Intensive Day-Use Recreation

Maintain and enhance existing project recreation facilities and lands, as well as develop new facilities to help meet current and projected needs for day-use recreation facilities.

(1) Rationale.

Day-use activities are the prime recreational use at MCP. The project serves 250,000 visitors each year, with 90 percent of these visitors from the Walla Walla Valley. The MCP is located adjacent to the city of Walla Walla which, along with the surrounding area, has a combined population exceeding 50,000 within a 15-to 30-minute drive of the project. Recreation activities will increase within the Mill Creek MA.

Virgil B. Bennington Lake is the only major body of water available in the Walla Walla Valley for recreation, and receives heavy use. The day-use activities with greatest participation are "other," fishing, sightseeing, boating, picnicking, and swimming. Boating and fishing facilities are the most overcrowded, and will be given the highest priority in regard to recreational development.

(2) Implementation.

In order to meet both current and future needs, the following facilities may be added to MCP (see specific management RO's for the location of access for persons with disabilities and the elderly to fishing facilities):

• auto parking at Rooks Park
• a restroom
• trails (see photo 3-5)
• picnic area
• group shelters
• a swimming beach
• fishing docks (see photo 3-4)

These items will be developed and funded in accordance with current regulation and policy. Other avenues to accomplish the necessary improvements will be pursued (e.g., involvement of volunteers, Boy Scouts, the Washington National Guard, local associations, clubs, and organizations). These groups will be contacted and encouraged to participate in programs oriented toward assisting in the improvement of Mill Creek lands.

d. Project RO Number 4--Low-Density Dispersed Recreation.

Provide opportunities and support facilities for low-density dispersed recreation activities (see photo 3-6).

(1) Rationale.

Because of the close proximity of the MCP to the city of Walla Walla, it helps fill regional needs for low-density, dispersed recreation in a natural and semi-natural setting. Project lands are used for a variety of activities that do not necessarily occur in a developed park setting. These include activities related to the consumptive and non-consumptive use of wildlife and fish. Fishing is popular at MCP, especially in the spring. Upland gamebird hunting is allowed in public areas where it does not conflict with the safety of project visitors and staff, and complies with state game management regulations. The MCP is a resource for birdwatching and nature study. Many people, particularly local residents, use the undeveloped areas for walking, nature study, and other passive activities. Visitors seeking recreation opportunities in these undeveloped settings use access points at Rooks Park, the Project Office, and the Lake Recreation Area.

(2) Implementation.

Continue to provide dispersed low-density recreation opportunities at MCP. These activities will primarily take place on lands classified as Multiple Resource Management. These areas will contain only limited development.

e. Project RO Number 5--Safety.

Provide a safe environment for the public (see photo 3-7).

(1) Rationale.

The visiting public is entitled to a reasonably safe environment. Because of the variety of uses at the project, there is a potential conflict and safety hazard created by the water resource structures and visitor use. The Safe Drinking Act requires monitoring and assurance of safe drinking water in public water systems.

(2) Implementation.

All project development will be coordinated with the District safety office, and appropriate actions will be taken in the design or management of MCP. Drinking water quality will be monitored, and all necessary actions will be taken to protect public health.

f. Project RO Number 6--Water Quality.

Achieve State and Federal standards of water quality that protect primary contact recreation (see photo 3-8) and maintain standards for wildlife and fisheries.

(1) Rationale.

It is in the public interest to provide water quality that protects beneficial uses that have been assigned to each water body (stream reach or lake) by the State of Washington.

(2) Implementation.

A plan will be developed for the project and incorporated into the OMP. This plan will include measures such as maintaining Virgil B. Bennington Lake at a consistently higher elevation, and providing instream flows. A water quality monitoring plan will also be incorporated into the OMP.

g. Project RO Number 7--Boundary Identification and Security Protection.

Identify MCP's boundaries through monumentation and fence as needed to designate these, and provide protection from encroachments (e.g., livestock, agricultural, and vehicular).

(1) Rationale.

Currently, approximately 23 percent of the project boundary that contains fee lands is not monumented. The majority of the MCP is surrounded by agricultural crop areas and pasture. Encroachments on project lands generally are agricultural (see photo 3-9). Monumented and fenced areas are slowly covered by plowing practices and eventually the project monumentation is lost. Existing monumented and fenced agricultural encroachments can be solved by real estate actions, but a method to prevent future occurrences needs to be implemented. The areas where encroachment is likely should have the highest priority. Encroachments cannot even be monitored in areas where the project boundary is not identified.

(2) Implementation.

Monument and identify, through fencing and signage, unmonumented project boundaries. Prioritization of monumentation fence locations will be established. Monumentation and boundary identification will be completed as soon as possible. Monumentation will be completed prior to fencing of lands.

h. Project RO Number 8--Interpretive Facilities, Signs, and Programs.

Provide additional identification, interpretive, and display facilities (see photos 3-10 and 3-11).

(1) Rationale.

Providing these facilities will allow visitors to identify Corps facilities and become acquainted with the ecological, cultural, and aesthetic resources and activities of the project and its environs. Little effort has been directed towards interpretive facilities for visitors to the project. As stated in RO Number 3, the demand for interpretive displays will increase by 49 percent. The recent name change of the reservoir, and the incorrect usage of Mill Creek Lake Project instead of Mill Creek Project, will cause some additional confusion. These and other project features need to be clarified for the public. Rooks Park and the Levee Trails are an excellent area for such interpretive information. New signs are needed for Corps identification, location, and operation of facilities. This report has identified associated historical information. The MCP currently occupies 166 acres of the 1860's Timber Reserve for Fort Walla Walla, and the Nez Perce Trail came within 400 feet of the MCP boundary. Also, the fact that MCP was 50 years old in 1992 is of historical interest. The project offers a variety of ecological features that have potential for interpretive displays. These include geologic faults, wetland and riparian areas, wildlife, and vegetative cover.

(2) Implementation.

An interpretive plan will be developed as part of the OMP within the Corps, and will be coordinated with other Federal, State, and local agencies and institutions. The plan will include the development of interpretive features at MCP. Interpretive features, as part of other recreation improvements at the project, will be constructed as funds become available.

i. Project RO Number 9--Environmental Education Area.

Designate MCP as an Environmental Education Area for the purpose of expanding environmental education in the Walla Walla community (see photo 3-12).

(1) Rationale.

The MCP has served informally as an outdoor classroom for the community. Whitman College, high schools, and elementary schools have all utilized the project for environmental education because of its close proximity and diverse ecological aspects.

The MCP and its associated diverse vegetation form an ecological island surrounded by both a drier steppeland region and extensive pea and wheat fields. The project promotes high biodiversity among plant and animal systems within its borders by providing food, water, and cover for wildlife through a unique combination of associated topographical characteristics, distinct soil types, and unusual geological attributes. Zonation and fenced borders allow the Corps to preserve and protect this biodiversity throughout the year. Ultimately, the project's location, just southeast of the city of Walla Walla, allows the public a chance to view wildlife in a natural setting that is close to the urban area.

The Walla Walla District has a comprehensive state-of-the-art GIS database for MCP. This spatial and non-graphic database has been utilized by local organizations, and will continue to be available as an environmental education tool.

(2) Implementation.

Solicit support from the scientific and educational communities in the Walla Walla Valley for such a designation. If the interest is there, a strategic plan with implementation measures would be developed. A Memorandum of Agreement would be signed by all interested parties that define each party's role and the intent of such an endeavor.

j. Project RO Number 10--Wetland and Riparian Protection.

Protect and limit impacts to wetlands and riparian corridors on the project in conjunction with the needs of maintaining the flood control mission of the project, water quality, anadromous and resident fisheries, and wildlife benefits (see photo 3-13).

(1) Rationale.

Wetland habitats and riparian corridors are a valuable and unique ecological feature of the Walla Walla Valley. Their close association with water makes them critical for wildlife diversity, fisheries sustainability, groundwater recharge, biofiltration, and recreation opportunities. Very little of these habitat types are available for public access and are protected for the values identified. Much of the wetland and riparian habitat present on the project is also closely associated to project structures and the need for efficient operation of the MCP.

(2) Implementation.

Foster the protection of wetlands and riparian habitat through careful planning and coordination of the operational needs, these habitat features can be maintained in a healthy and functional status. Water is a critical element of these habitats, and must always be provided to keep the habitats viable. No unnecessary removal or alteration of the systems will be promoted.

k. Project RO Number 11--Wildlife Habitat.

Continue to preserve, maintain, and enhance existing wildlife habitats on MCP lands for resident and migratory species.

(1) Rationale.

Since the early 1950's, the potential for MCP to provide habitat for wildlife has been recognized. Over the last 40 years, trees, shrubs, and grasses have been planted (see photo 3-14). Maintenance of existing habitats is necessary to continue to provide for healthy wildlife populations. The upland portion of MCP is an ecological island surrounded by agricultural development, making existing habitat critical for resident wildlife. Migratory wildlife, both latitudinal and elevational, depend on MCP habitat as a resting and feeding area. Much of the existing wildlife habitat has been maintained to provide the greatest benefit to the wildlife that depends on it.

Existing developments and features will be upgraded to the level where they provide the benefits to intended wildlife species. If development efforts are less than successful, revisions of the plans will be made to allow for the greatest benefit to wildlife species. Habitat features must be functional and fulfill the needs of species during every season of each year.

(2) Implementation.

All development will be planned, designed, and constructed so that it has minimal negative impact on wildlife habitats should be primarily ensured by the Corps. Opportunities will be used to enhance wildlife habitat. The Corps will work in cooperation with other agencies and the public.

l. Project RO Number 12--Fish Habitat and Passage.

Maintain and enhance a stratified fishery in Virgil B. Bennington Lake for resident trout and entrarchids. Maintain and enhance the anadromous and fluvial fishery corridor in Mill Creek Channel by maintaining flows and facilities for successful passage of anadromous fish runs in Mill, Yellowhawk, and Garrison Creeks.

(1) Rationale.

Lake fishing is the single most popular recreation activity at MCP. The lake is a unique feature of the Walla Walla Valley, and is the only public standing water body within 28 miles. The only lake of similar size is over 40 miles distant. Currently, water is diverted into the lake only in spring to bring up the lake elevation to conservation elevation 1205. However, as soon as the irrigation needs are greater than streamflows, the diversion of water into the lake is terminated. This results in a lowering of the lake through evaporation and seepage, causing elevated water temperature, dissolved oxygen depletion, and loss of cover. Much potential exists for enhancement by increasing submergent and emergent vegetation to function as an oxygen regulator in the aquatic environment.

Mill Creek serves as a corridor for migrating steelhead that move between subbasin spawning grounds, the Columbia River and, eventually, the ocean. In order to maintain fish migration downstream of the dam, a minimum flow needs to be provided during migration season.

(2) Implementation.

At Virgil B. Bennington Lake, continue the stocking of rainbow trout by WDW. Develop a fisheries habitat improvement plan for the lake. Implement a plan to maintain higher lake elevation throughout the year when water is available, and explore the possibility of maintaining water levels and minimum inflows throughout both the non-irrigation and the irrigation season. Sufficient spawning and rearing habitat and improved water quality need to be developed and maintained for the ishery to self-perpetuate.

Maintain and improve anadromous fish passage facilities on MCP. Maintain water flows downstream, as allowed by the State, to allow migration of anadromous fish upstream to spawn. Coordinate with WDW, the water master, WDF, and ODFW to improve flow and passage conditions through MCP (see photo 3-15).

m. Project RO Number 13--Species of Special Concern.

Preserve, maintain, and enhance habitat for species that are classified as species of special concern at MCP in the future.

(1) Rationale.

The bull trout (Salvelinus confluentus), which inhabits portions of Mill Creek, was petitioned for listing under the Endangered Species Act (ESA) in October 1992. A positive determination that listing may be warranted was issued on May 17, 1993. The USFWS has 12 months to officially list and provide guidance for protecting the bull trout.

The margined sculpin (Cottus marginatus) and the mottled sculpin (Cottus bairdi) are also found within the project area. Both sculpins are considered to be native species by the State of Washington, and may be rare enough to merit special protection (USFWS, 1993). The margined sculpin is found only in the Walla Walla River and Umatilla River drainages (Lee et al., 1980).

Under the provisions of Section 7 of the ESA of 19973 and the Fish and Wildlife Coordination Act of 1958, actions that may affect endangered or threatened species or their designated habitat must be coordinated with USFWS. Endangered and threatened species are protected under Federal and state statutes and regulations.

(2) Implementation.

As flora and fauna associated with Mill Creek become listed as threatened, endangered, proposed for listing, or candidates for consideration of listing (as determined by the ESA), any actions proposed for Mill Creek would need to be carefully considered and coordinated with USFWS and WDFW. Consideration should be given to determining what, if any, effect project actions may have on the species of concern. The proposed actions would include changes to existing operation and maintenance of the project waters and recreation, as well as new construction.

When appropriate action is warranted, CENPW will survey and identify the habitat of the species of concern. Plans will be made for habitat preservation and improvement. Interpretive facilities that explain the preservation described by RO Number 5, will be provided.

n. Project RO Number 14--Cultural Resources.

Preserve, maintain, and enhance cultural resources on project lands.

(1) Rationale.

Currently, there are no known cultural resources on the project. However, if any are found, it is important to protect them so they can provide information when studied in an undisturbed condition. Cultural resources are protected under Federal and State statutes and regulations. Historical information associated with the project has been identified in volume 2. The MCP contains 166 acres of the original Fort Walla Walla Timber Reserve, and the Nez Perce Trail is within 400 feet of the MCP project boundary. Additionally, the project is now 50 years old, and has historical value in and of itself (see photo 3-16).

(2) Implementation.

If any significant historical site is found, the District archaeologist will be notified and will initiate appropriate action to survey, identify, and monitor cultural sites. When needed, provide appropriate management measures. Provide interpretive facilities where appropriate, as described under RO Number 5.

o. Project RO Number 15--Aesthetic Resources.

Protect, preserve, restore, and enhance the aesthetic resources of the MCP.

(1) Rationale.

As stated in the National Environmental Policy Act (NEPA), all Americans have the right to be assured of aesthetically-pleasing surroundings. The Corps regulations and guidance calls for the Corps to consider and provide an aesthetically-pleasing environment for the public. The MCP presents many compelling reasons for management of aesthetic resources, especially visual. Its landscape, featuring long vistas, rolling topography, and a body of water, is of high visual quality. The MCP's location in an ecotone (a transition zone between the Blue Mountains and the Walla Walla Valley) enhances its aesthetic value by heightening the visual awareness of the user. It is also in a transition area with manmade development, and it is the first major undeveloped urban area east of the city of Walla Walla. The number of people attracted to the project each year is high--250,000. Those who come principally to sightsee (approximately 15,000) attest to its visual attributes. The number of visitors will increase, due to the proximity to the city of Walla Walla, which is growing at a rate higher than the State average. The MCP needs to be managed for visual resources since its landscape has a high scenic quality and high visitation, and there is an increasing public sensitivity to the visual environment and negative impacts on it (see photos 3-17, 3-18, and 3-19). It is in the best interest of public and private concerns to provide a quality visual environment (refer to volume 2, section 3, paragraph 3.04.). These factors are also reasons to complete a Visual Resource Management Study.

(2) Implementation.

Implementation will be accomplished by development of guidelines and inclusion in the OMP. Cooperation and coordination between the Corps and adjacent land managers and owners to minimize and eliminate negative visual impacts will be encouraged. Existing visual resources will be evaluated in a Visual Resource Management Study to determine potential improvements or changes to lessen impacts. Many changes can be effected through operation and maintenance funding such as environmentally-compatible painting, plantings, and other upkeeping functions. Guidelines and future developments for operation, recreation, and wildlife will be closely coordinated with the Corps' landscape architects, environmental designers, and Operations Division personnel to ensure minimal negative impacts. All new project features will be designed and maintained so that the visual resources associated with MCP will be protected, preserved, or maintained to the maximum extent practicable (refer to Engineer Pamphlet 1165-2-1 and section 6, Design Criteria.

3.03. References

USACE, 1983

U.S. Army Corps of Engineers Recreation Use Survey. Walla Walla, Washington, Walla Walla District (unpublished).

USACE, 1980

Corps of Engineers ER 405-1-12, 27 October 1983, (Change 23).

USACE, 1987

Corps of Engineers ER 1130-2-435, December 1987.

USFWS, 1993

Personal Communication with Paul Mongillo, July 1993.

4.01. General

This section presents land classifications for MCP. These classifications can be considered zoning plans in the sense that they allow for different types of management and development within each land classification category. The classifications are based on the attractiveness of the resource, as well as their protection, their capability, public desires, and agency missions and policies. The process used to determine the assignment of these land classifications is outlined in volume 2, section 4, Synthesis.

The land classifications, along with the project-wide RO's, provide a conceptual guide for the use, management, and development of all project lands. Project RO's were discussed in section 3.

Land classifications have been assigned to all MCP lands. Classifications are assigned to individual land parcels at MCP, and these land parcels are commonly known as management units, and are further defined in section 5. They are further defined, and the descriptive criteria and conditions pertaining to each category are contained in paragraph 4.02., Land Classifications. They are also shown on plate 4-1.

A discussion of land allocations (the reason the land was acquired) can be found in volume 2, section 3, paragraph 3.03.c.(1)(f), Land Allocation; and plate 3-12.

The classifications shown on plate 4-1 conform to ER 1130-2-435, Preparation of Master Plans, dated December 1987. Full consideration has been given to the guidance offered in various engineering manuals and supplemental instructions, as well as all Federal laws governing development and management (see volume 2, Supporting Data, Item 2).

4.02. Land Classifications

a. Project Operations.

Lands classified for project operations are those lands used solely to provide for the safe, efficient, and continuing operation of the project. They could include lands required for the structure, operations center, office, and maintenance compound. At the MCP, the Mill Creek Diversion, Mill Creek Dam, and the future Mill Creek Office and Information Center fall into this category. Lands classified for project operations may also be used for low-density recreation and wildlife habitat when these uses are compatible with operational requirements. They may also be used in this way as long as they are not in conflict with the safety of visitors and project personnel or other basic project requirements.

b. Recreation.

Intensive (high-density) recreation use areas are defined as lands where facilities have been, or will be, provided to accommodate the recreational needs and desires of visitors in concentrated numbers. The MCP lands, or management units, that fall into this classification are Rooks Park, the Mill Creek Recreation Trail, Bennington Lake Recreation Area, and Bennington Lake Road. These lands can include lands that have no facilities but are required for open space purposes, make a wholly compatible recreation unit.

The development of intensive recreation use areas must be in harmony with the natural surrounding landscape. Facilities can include, but are not limited to, the following: access roads, parking lots, paved trails, underground utilities (i.e., water, electric, and sewer), restrooms, turf grass, shade trees, picnic shelters and tables, playgrounds, sports areas, nature center, interpretive areas, swimming areas, and boat launching.

There are several types of uses that are not permitted on intensive-use recreation areas. These include noncompatible manmade intrusions (i.e., pumping plants, underground or exposed pipelines or cables, overhead electric and transmission lines, non-project roads, and dredging and filling operations). Exceptions may be made when public need has been demonstrated and there is no viable alternative available. Measures that lead to habitat improvement for the benefit of wildlife may be performed on intensive-use recreation lands as long as these habitat improvements are compatible with recreation uses. No hunting will be permitted on lands classified as recreation. Permits, licenses, and easements will not be issued for noncompatible manmade intrusions.

c. Mitigation Lands.

This land use classification encompasses all lands acquired, or designated, specifically for mitigation purposes. There are 63.1 acres at MCP (the FWWTR Habitat Mitigation Unit) that were acquired as part of the Lower Snake River Fish and Wildlife Compensation Plan (LSRFWCP). This acreage is intended to mitigate for the loss of hunting and wildlife habitat caused by the construction of the Lower Snake River projects. These lands were transferred to MCP on July 7, 1992. Although intended primarily for wildlife mitigation, the following improvements are allowed: the construction of fences; and the planting of trees, shrubs, and native grasses; wildlife food plots; and the installation of watering cisterns. Low-density recreation activities (i.e., hunting, wildlife observation, outdoor photography, hiking, and sightseeing) are allowed and encouraged.

d. Environmentally Sensitive Areas (ESA's).

This land classification may include those lands where scientific, ecological, cultural, or aesthetic features have been identified. at MCP, the Mill Creek ESA and Yellowhawk-Garrison Creek ESA fall into this classification. Activities within this category must be managed to ensure that the sensitive area is not adversely impacted. Only limited development will be permitted in this classification, except for a portion of the existing debris barrier. Low impact management activities (i.e., erosion control, use restrictions, and interpretive displays) necessary to protect the integrity of the area may be permitted. No agricultural uses or grazing are permitted on these lands. Low-density recreation activities that do not require development (i.e., fishing, hunting, birdwatching, etc.) and do not negatively impact the value of the area are permitted.

e. Multiple Resource Management.

(1) Recreation--Low Density.

Low-density recreation lands are designated for dispersed, or low impact, recreation use. The South Mill Creek Trail Management Unit falls into this classification. The development of facilities and automobile access is limited or prohibited on these types of lands. The emphasis intended for this classification is to provide opportunity for picnicking, fishing, hunting, birdwatching, environmental education, hiking, bicycling, primitive camping, or other similar low-density activities. Benches, tables, sun shelters, vault toilets, and waste receptacles will be allowed, but utilities (i.e., electricity, water, and sewer) are not usually provided. Any added facilities must harmonize with the natural surroundings, and be nonintrusive to the environment. Landscape development or restoration, when necessary at all, will utilize plants native or naturalized to the area. Manmade intrusions (i.e., pumping plants, pipelines, transmission lines, non-project roads, and dredging operations) will not be permitted. Appropriate controls will be instituted to minimize the adverse impact to wildlife and the natural characteristics of the area. These lands can provide open space between intensive recreation lands and lands on the project, or adjacent to the project, that have incompatible land uses. No agricultural use may be made of any of these lands, except when it would be favorable to wildlife and compatible with low density recreation. Hunting is not permitted under this classification. Measures leading to wildlife habitat improvement can be a management objective.

(2) Wildlife Management General.

Lands classified for wildlife management are intended for the development and management of habitat for different species of wildlife. They include Bennington Habitat and Russell Creek Management Units. Licenses, permits, and easements will be issued for manmade intrusions (i.e., pumping plants, underground or exposed pipelines or cables, overhead transmission lines, non-project roads, and dredging or filling operations) only if it can be shown that wildlife habitat or low-density recreation will not be impacted. Exceptions may be made when a public need has been demonstrated, no viable alternative is available, and impacts are mitigated. Such outgrants will include the controls necessary to preclude or minimize adverse impacts to wildlife, fisheries, and the natural characteristics of the area. These lands are available for low-density recreational pursuits (i.e., hiking, picnicking, hunting, fishing, nature study, photography, birdwatching, etc.).

f. Easement Lands.

Easement lands are those lands where the Corps has easement rights for certain specified purposes. These easements are located on private or public property, but are necessary for project purposes. There are three areas classified in this way at MCP. The largest area, Russell Creek Flowage MU (73.26 acres), is located on private lands at the end of the Russell Creek Outlet Canal. The second area, Lower Russell Creek Canal MU (11.52 acres), is located along the Russell Creek Outlet Canal. The canal runs from lands below the Mill Creek Dam to Russell Creek. The third area, Rooks Park Road (2.49 acres), lies along Rooks Park Road, and is on lands owned by Walla Walla County. Development permitted by the Corps is specific to each individual easement. Volume 2, section 3, paragraph 3.03.c.(d), and plate 3-11, contain a detailed description of these easements.

4.03. Land Classification Acreage

Table 4-1 is a list of the 611.5 acres of land and water administered by the Corps, by land classification. The location of these areas is shown on plate 4-1. Table 4-2 lists land classification acreage and management units, as well as easement lands. Detailed maps of each management unit are contained in section 5.

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Mill Creek Master Plan Coordinator