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23 May 2011

Public Comments on Carter Lake Project

The following comments were sent to officials of the Omaha Parks and Recreation Department, which is currently accepting birds for construction of shoreline stabilization, a wet basin, targeted dredging and associated work at Carter Lake. There was no acknowledgment from any officials that this document was received. An engineer at the contractor's meeting did indicate they had received this information and were evaluating it.

Based upon extensive personal research and a close evaluation of the pending project at Carter Lake, the following comments are being provided to lessen the impact of the project on the myriad of birds which use this oxbow lake along the Missouri River.

This lake - originally called Cut-off Lake - is the result of a shift in the channel of the Missouri River. It was not created due to any human actions, despite what a plaque on the Kerrey Pedestrian Bridge might indicate.

The still waters of the lake have been an obvious haven for many sorts of fowl. Some of the first records for this locality were in 1886. Further occasional observations continued through the 1890s, and one of the foremost indications of bird use was in 1902, associated with the efforts of Frank Shoemaker, whose photographs taken at the lake are now - thankfully - preserved in a distinctive collection at the University of Nebraska-Lincoln archives.

Interest in birds at then renamed lake continued. From the mid 1920s, and for the next 15 years, other Omaha birders visited the lake environs to denote the species present.

Back in those days, the lake still had some of the natural, terrestrial habitats typical for the Missouri River floodplain.

Prominent in the site's history, was its official designation as a bird sanctuary in the early 1930s, in recognition of a preeminent sports writers in Nebraska's history - Sandy Griswold.

The bird sanctuary was first recognized by an Omaha city ordinance. "Prominent town men George Brandeis and Thomas Kimball, were on a committee of 50 folk that raised funds to place a memorial monument or marker in the city park now at the former Missouri River oxbow.

"The people wanted to remember 'Sandy's Creed'" for conservation of natural resources. There was a tribute in the April 1930 Sunday magazine of the local newspaper. Apparently a marker was placed at the park, but which eventually disappeared.

This particular recognition has been long forgotten, but not wholly ignored.

Lake Transformation

Though Carter Lake was created by natural forces, in the modern era, a coalition various agencies has worked hard to meld the lake to their wants. Housing on the Iowa side of the lake has meant a nearly complete loss of any natural condition of the shoreline. Homeowners and a golf course built a wall to protect their place from the lake waters.

Each effort celebrates their association with the oxbow lake, yet a primary task has been to separate their property from a natural connection with the lake.

The current project continues this trend in transforming the naturally-created lake to an artifice of engineering.

Certainly there has been a willing coalition of agencies, etc. working on this project, but each one has a particular mission which they want to see achieved.

It has all been wrapped into an effort to improve water quality for the human community.

Based upon the information reviewed and discussions with project participants, this effort has had little regard for the wild birds which have been using this locality long before there were any human settlers, a town and housing.

Yet this historic natural legacy has long been and continues to be ignored.

The Carter Lake project - for which bids are now being accepted - appears to be driven by three particular goals:

1) use park land to address the needs of the stormwater/sewer separation project by the City of Omaha.
2) make the lake nice for home owners on the Iowa side of the lake.
3) provide a fisheries resource for local residents.

There has been no indication that could be found on how project measures have taken into consideration the natural values of the setting, nor any impacts on the local avifauna.

A Birds Eye Perspective

In anticipation of this project, numerous surveys have been conducted of bird use of the local environs in the Carter Lake District. Records of the bird use were made for the following sites:

  • Levi Carter Park
  • Levi Carter Pond
  • Iowa West Ranch, as noted from across the lake
  • Kiwanis Park

During the many bird surveys done this spring, there were no Bald Eagles observed. News articles in previous years indicated Carter Lake as a prime place to see this majestic raptor. Was the lack of eagles due to the loss of large fish because of the fish-kill done last autumn? Although there weren't enough surveys done in the late winter period, there were no records of mergansers, though they have been commonly seen on the lake's waters in previous years, by numerous observers.

The following is a tally of the birds noted in particular at the pond area, which is a distinctive habitat due to its shallow water conditions, and very suited for fowl.

Common Name

3/30

4/1

4/9

4/12

4/17

4/20

4/23

4/25

4/27

4/29

5/1

5/3

5/7

5/17

Canada Goose

-

-

-

1

-

1

-

-

-

2

-

-

-

-

Wood Duck

4

3

7

1

6

2

2

2

2

6

10

5

3

7

Mallard

2

2

-

-

4

-

6

-

7

2

-

-

3

3

Blue-winged Teal

-

1

18

4

7

12

12

12

9

6

2

2

1

-

Northern Shoveler

4

-

6

-

12

6

5

2

11

7

6

6

8

-

Green-winged Teal

-

-

3

1

-

-

-

-

-

-

-

-

-

-

Pied-billed Grebe

-

-

2

1

-

-

1

1

-

-

-

-

-

-

The Green-winged Teal was noted only at this particular place, while the other species were seen elsewhere at the lake.

These details do indicate the value of the pond for dabbling ducks, which can now "tip-up" and find forage in the shallow waters.

Dredging the pond to a consistent depth of 4.5 feet will render the waters too deep for each of the ducks indicated. And as there is very little shallow water within the lake proper, the proposed plans will have a deleterious impact to birds.

During the bird surveys carried out in a standard manner this year, there have been more than 75 species recorded, including notes derived from other metro-area bird watchers. Among the more than 600 records includes one of the Common Moorhen, which was last noted at Carter Lake in 1930.

Based upon a count of the species present, there have been more than 10,000 individual birds denoted on only 15 or so occasions during a five-month period. If further analysis was done, this value would readily reach an extent in the hundreds of thousands. If a valuation was placed on each bird-use day of $5, which is a paltry sum, there is a vast economic value of the lake habitats for migratory and resident birds.

Birds make no demands other than have a place to exist. Others undertake efforts to reduce the quality of wildlife habitat which makes places less friendly for the existence of wild birds. Carter Lake, based upon historic conditions and the priceless bird observations made in former decades, provide a dramatic perspective of change to the habitats which have continually meant a loss of habitat and decrease in diversity of representative avifauna.

This information has been previously summarized.

Project Suggestions

It had been my understanding that there would be an opportunity to provide comments on the final project design at a public meeting once the final plans were developed, according to a person at the Nebraska Game and Parks Commission who said there would be a meeting in this regard. This is obviously not the case, as there was no known opportunity for the public to review and comment on the final design plans, as they were finished and went right to the City of Omaha's bidding process.

In order to ameliorate the overall transition of Carter Lake from a somewhat natural lake to a designed water body, the following comments are provided. These slight changes would at least make somewhat of a lesser impact to the birdlife of the lake environs.

After a review of the current project plans, the following suggestions are provided, specifically for the north wet detention basin. The numbers correlate with the numbers given on the associated figure of this pond and the pending lagoon.

Generally, dredging this pond to a depth of ca. 4.5 feet will effectively remove any value the place will have for dabbling ducks, which tip up to get food from the water. The species recorded prefer shallow waters.

Three Wood Ducks using deadfall at the Levi Carter Pond.

1) Deadfall logs in this immediate area and elsewhere are valuable roost sites notably used by the ducks. Each of these should be retained and placed in a suitable place once project work is completed.

2) Provide a secondary notch in the berm: the rock could be placed to where its upper extent is about four inches below the expected level of the water. This inhibits access to the berm which reduces the potential for disturbance to birds on the pond, reduces the extent of a visual barrier and improves the ability of birds and other swimming critters to readily access the entire water area of the pond.

3) Move the primary notch to within 2-3 feet of the eastern end of the berm. This also inhibits access, providing the same benefits given with item 2. Doing so allows the creation of an island which will be beneficial to the water fowl. This island should have an above water height of less than 8 inches and the dirt should be planted with a suitable species of grass.

4) Similar to item No. 2.

5) Similar to item No. 3. Moving this notch eastward also increases the thalweg of the flow, providing an improved opportunity to trap sediments and nutrients.

6) Every effort should be made to retain any and all vegetation along the eastern shore of the pond, as it provides a visual barrier to traffic on Grand Avenue. This barrier improves the quality of the pond habitat by reducing disturbance and increases the habitat diversity.

7) Shift the alignment of the proposed shallow water area to align with the bank. This will help change the thalweg away from the drain, perhaps assist in retaining water longer and thus the chance to retain sediment and nutrients. The designated plan alignment appears to direct water into the drain.

8) This area should not be dredged. Not doing so would provide an undisturbed refugia for pond biota which could then repopulate the disturbed areas of the pond basin. This would also help to retain some shallower water habitat.

9) Plant shrubs along the edge of the lagoon to provide a visual barrier to increase floristic diversity. Shrubs can also be being planted at other suitable places? There are no shrub species on the "designated" plant list, yet something such as the native dogwood would increase floral diversity, readily provide a viable natural barrier and add a floristic element to the park which is now dramatically missing.

10) Create a backwater area on the interior of the horseshoe-shaped lagoon. The project plan depicts a linear lagoon with an apparent depth of eight feet. With its steep sides, there will likely be minimal growth of any wetland vegetation or other features which would capture runoff sediments or nutrients. Creating a backwater on the interior of the lagoon could be easily accomplished by additional excavation. The water could get into the area via two suitable notches on the eastern side which would be hydrologically connected to the standard water pool. The elevation of the backwater could vary from a depth of 1-12 inches below the expected elevation of the water pool. This variable terrain would provide distinctive habitat for the lake environs by increasing texture and diversity of the park setting.

Apparently the lagoon is intended to help trap sediments and nutrients from stormwater runoff, but there are no constructs within the long and narrow construct. Shouldn't there be wetland vegetation or some other facet to help with improving water quality, before it reaches the lake waters?

Creating this shallow-water habitat would mitigate for the loss of similar habitat at the pond, reduce the disturbance factor in the lagoon as with the current proposed design, one person in the interior of the horseshoe could be noisy and cause disturbance to the entire lagoon area. Having a natural habitat would also remove the need for maintenance of the lawn monoculture typical for much of the park.

Area of Levi Carter Park where the lagoon will be constructed.

11) The engineering plan for the lagoon indicates there are about 20 trees of very sorts where this feature will be created. Many of these trees will be removed - though some could perhaps be moved - as a result of the project work. Each tree removed should be replaced with a new tree.

The following comments, apply to areas of the project, other than the associated figure.

What is the need for 21 breakwaters on the east shore of the lake. This seems excessive. These rock structures will create a visual "ugliness" to this section of the shoreline. Which raises the question of how visual aesthetics have been considered in the project plans?

Move the groin SP 63 a short distance southward and do not build SP 64. These two features are in close proximity and are redundant. They cater to the fishing crowd, yet increase the potential for disturbance to lake fowl.

This area around the lake island could be the place which could be rededicated as the Sandy Griswold Bird Sanctuary, as it is long past the time when this city of Omaha approved feature was first recognized. This would be an important measure in realizing the birdly value of the lake, rather than fisheries getting the sole attention, as has been the obvious situation thus far. Perhaps a community group could provide a suitable marker?

Further details are requested for the following questions, as suitable details could not be determined by reviewing the available bid documents available online.

How will the credentials of the "field representative" be evaluated to ensure they have the knowledge and skill needed to accurately determine the presence or absence of bird nests?

What species are included in "Seed Mix 'A'" which is to be planted on four acres of land.

Has the list of tree species been reviewed by a botanist to ensure that only species native to the region are being planted?

Land Management

Distinct from the lake project is the need for additional land management efforts at Levi Carter Park.

In particular, at the so-called "Meadow in the Making" area on the west side of the lake, across the street and southward from the care-takers house, numerous volunteer growth cedar trees are growing. If these unneeded trees are not removed, they will overwhelm the setting and create an unwanted vegetative condition which will be nothing like a meadow setting.

With proper tools, the trees could be cut and removed in a day's time. Perhaps the Carter Lake volunteer group could assist with this task?

Nearby, along the shore of the lake, is an area where the unwanted invasive species, phragmites is established. If this species is not eradicated, it will spread and become an unwanted blight.

With the numerous trees marked with a numeral for removal in the Levi Carter Park area, once these "old-growth" trees are removed, the park lands will be mostly lawn. There needs to be an immediate effort to plant new trees to replace those "relict" trees slated for removal.

The new trees would not replace the old trees so important to cavity nesting bird species such as the Wood Duck and woodpeckers, though at least the park - with some effort at tree replacement - would be more than a boring expanse of monoculture turf grass which has a trivial natural value.

Carter Lake is much more than an artificial construct. The current project needs to take this into account and include project options which is a small manner will give some consideration to the natural values of this important Missouri Valley habitat.