draft 10/21/02, needs bio’s review.
MISSISSIPPI RIVER - POOL 14 ENVIRONMENTAL PLAN
DESIRED FUTURE HABITAT CONDITIONS
Description of Pool 14:
Pool 14 is the 29.2 mile segment of the Mississippi River extending upstream from Lock and Dam 14 near LeClaire, Iowa to Lock and Dam 13 at Fulton, Illinois. Bordered by the states of Iowa and Illinois, Pool 14 includes ____ acres of public lands and waters. Although the project area is Pool 14, planning considerations extend to areas which impact pool resources, including watersheds, natural floodplains behind levees, and private lands within the pool.
Pool 14 encompasses the natural floodplain throughout most of the pool’s reach. Exceptions include urban areas, portions of a levee and drainage district, and the ___ acre Princeton Wildlife Area (Iowa), which is bounded by a low levee with water control structures facilitating wetland management. Urban and industrial development at the cities of Clinton, Camanche, and Fulton characterize the upper one-third of the pool. Islands and backwaters associated with the Wapsipinicon River are a dominate feature at mid-pool. The lower pool typifies the Fulton-Rock Island gorge of geomorphic reach 5, constricted, devoid of islands, and with habitat limited to main channel characters. The Wapsipinicon (Iowa) is a major tributary with a watershed over 2,400 square miles. Several smaller streams add another 500 square miles to tributary watersheds.
Backwater habitats have declined throughout the upper one-half of the pool, and that trend is expected to continue. Accelerated accumulation of sediment is a serious problem and has resulted in loss and deterioration of both backwater and channel habitats. Vegetation is generally very sparse, although emergent aquatics remain vigorous and the dominate component within the Princeton Wildlife Area. The Pool contains one of the largest concentrations of Higgins eye mussel on the Upper Mississippi River.
Public lands and waters within Pool 14 include the Upper Mississippi River National Wildlife and Fish Refuge, General Plan Lands of the Nine-Foot Navigation Project, and lands and waters owned by the States of Iowa and Illinois.
Resource Problems and Issues:
1. Fine sediments are accumulating at accelerated rates within backwaters and other floodplain locations due to high suspended sediment concentrations and the reduced sediment transport capability of the navigation project.
2. Habitats critical to migratory birds must be maintained, especially aquatic food resources and woodlands.
3. Coarse sediments, or bed load sediments, accumulate in side channels where they fill valuable habitats and restrict flow.
4. Elevated water tables favor moisture tolerant forest species and limit site potential for species diversity.
5. Watershed discharges into Pool 14 contribute to significant water quality and habitat problems which impact natural resources. Issues and examples include accelerated sedimentation with associated nutrient and contaminate delivery (see 1 and 3 above) and urban and industrial discharges.
6. Locks and dams 13 and 14 restrain fish passage between pools .
7. Information is needed to better assess and manage Pool 14 mussels, especially the Higgins eye population.
8. The current Pool water management regime, especially the avoidance of seasonal low water, removes much potential for periodic regeneration of aquatic habitats.
1. Restoring the full range of bottom contour and depth (bathymetric diversity) within backwaters will address Resource Problem 1. The river’s natural energy may be harnessed at select sites with features designed to (a) scour sediment, (b) maintain sediments in suspension to prevent accumulation, or (c) divert sediment laden flows. At sites protected from accelerated sedimentation but where natural processes cannot restore desired bathymetry, dredging can replace natural cutting and scour. Watershed management with Best Management Practices can reduce soil loss, stream turbidity, and rates of sediment accumulation.
2. Pool management which effectively maintains emergent and submersed aquatic vegetation and forests will insure availability of habitats critical to migratory birds (Resource Problem 2). Vegetation provides direct habitat benefits and positively influences other important resources, such as aquatic macroinvertebrates and fishes. Opportunities to restore or maintain aquatic vegetation include: (a) island maintenance or development to shelter aquatic areas, (b) water level management, especially to provide periodic low elevations, (c) actions within watersheds and the pool to lower turbidity and sedimentation rates, and (d) continue and expand water level management for moist soil, wet meadow and emergent aquatic vegetation at Princeton Wildlife Management Area. Opportunities to maintain forest communities are discussed in item 4, below.
3. Design and construction of projects to utilize the river’s hydraulic energy to open or maintain side channels can be accomplished to mitigate Resource Problem 3. Opportunities include (a) erosion protection of key side channel shorelines, (b) experimental structures designed to alter flow and increase bathymetric diversity within side channels, (c) flow regulation into degraded side channels and (d) development of bathymetric and sediment transport models for Pool 14 to aid analysis and project design. Dredging can also restore side channel productivity, and is especially appropriate when used in combination with techniques which sustain the desired condition.
4. Mitigating the long-term impacts of an elevated water table can help improve forest regeneration and tree species diversity at select sites (Resource Problem 4). Opportunities include (a) raising ground surface elevation, (b) use of intensive regeneration aids, (c) careful management of existing diverse stands, and floodplain edge sites, (d) experimental plots testing a variety of forest management techniques, and (e) examination of pool water management profiles and topography to identify sites with best potential for diverse forest management.
5. Watershed related water quality issues are addressed by several authorities, but river managers can influence effectiveness of local programs (Resource Problem 5). Opportunities to improve watershed impacts can include (a) collaborative efforts to reduce upland soil erosion, (b) improvements to lower tributary characters including bank erosion of coarse sediments, (c) supporting efforts to solve specific water quality problems, such as high concentrations of ammonia in important habitats, and (c) initiation of needed monitoring if information is not available.
6. Structures or modification at Locks and Dams 13 and 14 can improve fish passage (Resource Problem 6). Opportunities include the design and construction of fish ladders or amending lock or dam operations.
7. A mussel population and habitat inventory can provide needed and basic information on Pool 14 mussels (Resource Problem 7). Opportunities include (a) collaborative inventories involving all agencies, (b) a contracted study funded by an applicable authority and (c) development of best management guide for priority sites.
8. Timely water level fluctuation, planned within the constraints of the navigation system, can induce biological responses which rejuvenate aquatic habitats (Resource Problem 8). Opportunities include periodic reduced summer water elevation designed to mimic natural summer low flow events.
To facilitate planning and illustration, proposed actions are organized within geographical units. Geographical unit boundaries and the locations of actions proposed within Pool 14 may be located on the Desired Future Habitat Conditions maps which follow this section.
Upper Pool 14:
Provide for controlled flows through Lock and Dam 13 spur road to isolated aquatic areas within the Jacobs Slough complex in Pool 14.
Restore depth diversity for fish species by dredging within the Jacobs Slough complex.
Clinton / Fulton Harbors:
Restore depth to alleviate winter oxygen depletion and provide important fish over-wintering habitat.
Beaver Island Complex:
Restore shallow aquatic habitat in the upper reaches of rapidly accreting wetlands. Consider pothole blasting technique.
Restore over-wintering habitat for centrarchids with dredging.
Increase island elevation with dredged material to introduce and sustain mixed bottomland tree species.
Reduce accelerated sediment accumulation in backwater lakes by diverting high flows with a low, deflection berm
Restore side channel and braided slough habitats.
Restore dispersed over-wintering habitat for centrarchids.
Improve island site index for mixed bottomland tree species by raising ground elevation with dredged material from over-wintering habitat project.
Schrickers Lake Complex:
Support solutions to resolve ammonia influx from Rock Creek watershed which threatens a unique backwater.
Restore full range of bathymetric diversity.
Assess potential for converting agricultural site to moist soil vegetation management.
Develop a monitoring and best management response plan for the Higgins eye population and associated habitats, including a definition of site characters, to help ensure the protection and preservation of this population and habitat.
Improve island site index for mixed bottomland hardwoods and plant select tree species. Utilize dredged material from channel maintenance, topped with fine sediments to raise the ground elevation.
Wapsipinicon Bottoms / Princeton Wildlife Area:
Continue water level management on Princeton Wildlife Management Area to ensure consistent availability of quality emergent aquatic and moist soil communities in Pool 14. Expand opportunities for similar water management on the Wildlife Area.
Identify and pursue opportunities to enhance the diverse habitats at the mouth of the Wapsipinicon River. Advocate for floodplain restoration on the lower Wapsipinicon using programs as the Wetland Reserve Program.
Maintain diversity within the forest community with intensive forest management.
Pool 14 Entire:
Complete bank stabilization or flow modifications at sites where rapid bankline erosion threatens pool diversity. The project should begin with a pool-wide inventory.
Review Pool 14 water management and determine feasibility, impacts and anticipated results of potential changes in water management, especially the partial restoration of seasonal low water elevations.
Inventory and assess mussel populations throughout the pool and design appropriate habitat management.
Inventory and assess diving duck use and the availability of priority food resources in the lower one-half of the pool.
Pool 14 Watershed:
Support and participate in programs and activities of the Wapsipinicon River Alliance, the Rock Creek Watershed Initiative.
Advocate for implementation of the Wetland Reserve Program or similar programs on the Wapsipinicon River floodplain.
Support solutions to high ammonium concentrations in Schrickers Lake.
Upper Mississippi River System:
Develop pool-wide environmental planning aids, including hydraulic models, topographic and bathymetric surveys, substrate maps and other information needed to facilitate engineered solutions for habitat diversity.
Design, construct and test structures to maintain or restore desired habitat features.
Expected or Desired Results:
1. A combination of engineered solutions will aid in the restoration and maintenance of important habitat features of side channels and backwaters at select sites. Sediment accumulation attributed to the navigation project can be reduced at project sites to maintain or restore important habitat values. Aquatic values and the life span of targeted backwaters will be extended. Fish over-wintering habitats will be maintained within five mile intervals. Side channels targeted for improved management of coarse sediments may be maintained indefinitely. Main channel training structures, however, will preclude much potential for large-scale regeneration of aquatic habitats, and the long-term trend to a less diverse system will continue.
2. Habitats critical to migratory birds, especially aquatic food resources and forests, will be improved and extended if the problems of suspended sediments and sustained high water elevations can be mitigated. Water management alternatives, even in small scale, promise important, periodic rejuvenation of aquatic vegetation.
3. Expected or desired results related to sediment problems within side channels are included in number l above.
4. Naturally sustained diverse forest communities in Pool 14 can be developed on sites raised significantly above the water table or maintained on higher areas of the floodplain edge. Careful management and intensive regeneration efforts will maintain desirable communities on some existing sites. Sediment accumulation will slowly improve the woodland site index at some locations. There will be opportunities for forest restoration on lands currently in agricultural production within levee and drainage districts. Forest stand improvement goals will be established throughout the Pool.
5. Long-term improvement in watershed management is expected to reduce sediment loads from immediate watersheds and the basin. River managers must ensure that river impacts are a measured cost of upland erosion and that Mississippi River natural resource and water quality issues are represented in planning and implementation of watershed management. Programs which benefit restoration of tributary floodplains as the Wetland and Conservation Reserve Programs or the Emergency Wetland Program will be identified and supported.
6. The installation of fish passage structures or amended operations at locks and dams 13 and 14 will reduce restrictions to fish movements.
7. Mussel population and habitat monitoring will be maintained and best management guidelines will be established and implemented.