[Note added by SaveChatfield.org: The following letter about Chatfield Water Reallocation was shared with us by Hugh Kingery, editor of Colorado Breeding Bird Atlas (1998 Edition) and author of Birding Colorado: Over 180 Premier Birding Sites at 93 Locations (2007)]

PO Box 584
Franktown, CO 80116-0584
August 16, 2012

Colonel Robert Ruch, Commander
USACE Omaha District; CENWO-PM-AA
ATTN: Chatfield Reservoir Storage Reallocation FR/EIS
1616 Capitol Ave.
Omaha, NE 68102

Re: Chatfield Reallocation Environmental Impact Statement

The EIS offers inadequate justification, poor environmental analysis, and unsatisfactory mitigation for the devastating effects of Alternative 3. The other alternatives would have lower environmental impacts and should receive higher priority than # 3. The EIS didn’t even look closely at them. In selecting Alternative 3, the EIS dismisses all the destructive effects without a valid comparison with the other alternatives. Even the title of the EIS suggests a pre-determined outcome.

I urge you to revise the EIS to provide credible analysis of the other alternatives and compare them with the effects of Alternative 3.

Problems with Alternative 3:

1. Water levels:

The EIS describes different fluctuating water levels:

  • During the growing season, an “estimated” “average” of 2-3 feet (4-76, 4-81);
  • During late spring and early summer (the growing season), “average peak fluctuation” of 3 feet (4-81);
  • Year-round, 6-7 feet (4-81, 4-91);
  • “On rareoccasions” 20 feet (4-81);
  • Seasonal fluctuations of up to 21 feet (4-91).

2. Wildlife Data

The wildlife discussion in the body of the report tries to summarize the bird data, but contains no citations except the casual surveys in Appendix Q.

EIS Discussion. Even with its copious bibliography, the body of the EIS shows little evidence that it used many of the references.

A more credible EIS would include data from and citations to:

  • The enclosed article in the Colorado Field Ornithologists’ publication, Colorado Birds. It summarizes a 12-year Census of Breeding Birds in Chatfield State Park on the South Platte. The study area, opposite the present Heron Overlook, had vegetation similar to the mature cottonwood forest that Alternative 3 will affect, particularly the section upstream from Kingfisher Bridge. The census provides data for four years pre-flooding, five years during the transition, and three years post-flooding (plus three more counts of colonial birds). It substantiates the importance of this habitat, with its different layers and niches, to the variety of nesting birds. (A Fifteen-Year Breeding Bird Census of a Cottonwood Grove and Heronry Before, During, and After Flooding by a Reservoir. (Kingery, 2009. Colorado Birds 43 (1): 26-45) [American Birds, published by National Audubon Society contains the original year-by-year studies.]
  • The 2006 Bird Checklist by Kellner and Spencer (which has more information than the mere list in the EIS); although the bibliography lists this checklist, the EIS contains only a bare bones bird list;
  • The bird banding operation at the Denver Audubon Nature Center, conducted by Rocky Mountain Bird Observatory and Audubon Society of Greater Denver for the last several years;
  • The monthly bird walks conducted by Chatfield State Park;
  • The monthly bird walks conducted by Audubon Society of Greater Denver.
  • Breeding Bird Atlas (the current one (2007-2012) as well as the first one (1987-1995) [Kingery 1998]).

3. Specific Bird Data

In discussing the specifics of bird occurrences in the park, the EIS conjectures, inaccurately, about the status of several species. The speculatory nature of the statements demonstrate the inadequacy of the bird investigation on which the EIS relies. Two point counts, one week apart, in one month, cannot possibly present an accurate analysis of year-round birdlife.

(Had the EIS relied on more accurate references, and studied the few that it cites, it would have contained more accurate data.) For example:

Western Snowy Plover

“This species could occur in the study area if beaches are left undisturbed by humans.” (3-71)

The species migrates through the study area in small numbers; it occurs particularly on the sandy spit that flanks the east side of the Marina.

Burrowing Owl

“Although this species has not been identified within the study area, burrowing owls have been identified south of Chatfield Reservoir during the breeding season. Because suitable habitat does occur in the study area, the owl could potentially move into this habitat.” (3-71)

In fact these owls have a history of breeding within the park. They occurred in the prairie dog town that formerly occupied the area designated as mitigation site SPR-1. They also bred for several years in the prairie dog towns that flank the Roxborough Park entrance road, though they have not used that area in the past 5 years or so, and as the EIS states, the site lies outside the directly affected project area.

Yellow-billed Cuckoo

“This subspecies requires patches of at least 25 acres of dense riparian forest with a canopy cover of at least 50 percent in both the understory and overstory. Given the strict habitat requirements of this subspecies, the western yellow-billed cuckoo is unlikely to occur in the study area.” (3-71)

In fact they have bred in the mature cottonwood forest that lies above Kingfisher Bridge and that the reallocation’s high water mark will inundate and that Alternative 3 proposes to remove. (Kellner 2006; Kingery 2009). Early birders even referred to a wet area within this section as “Cuckoo Slough.”

Large Raptors

On page 3-47, the EIS speculates about breeding by large raptors (Red-tailed & Swainson’s Hawks and Great Horned Owls). It posits, “They can be sensitive to human activity so nests may be uncommon.”

Contrary to this claim, Red-tailed, Swainson’s Hawks, and Great Horned Owls, in fact can and do breed in the Park.

Red-tailed Hawks nest along the South Platte in several places, irrespective of human traffic. A pair has nested for several years in a tall cottonwood visible from the Audubon Nature Center, despite regular foot traffic underneath it. They also have nested on the west side from Wadsworth Blvd., about 25 feet from the highway (just north of the Deer Creek entrance). [They even nest in urban areas: For the last two years both Red-tailed and Swainson’s Hawks have nested at the Wellshire Golf Course on South Colorado Blvd. in Denver. (Gregg Blew, Course Manager, pers. comm.)]

Great Horned Owls had a dozen nests in the Park for several years after it opened, many along the South Platte corridor and one in a lone tree 100 feet from the Deer Creek entrance station to the Park. As the EIS states (3-47) both the owl and the red-tail require tall, mature trees.

Swainson’s Hawks typically breed in tall trees associated with grasslands; I know of only one park site, along the Highline Canal west of the Roxborough Park road entrance.

Other raptors do nest in the Park: e.g., Cooper’s Hawk, Long-eared Owl, and Northern Saw-whet Owl. In 2012 three fledglings of the last spent several days hiding in a dense thicket in the mature forest south of Kingfisher Bridge (the forest, below the high water mark, slated for removal.) The first two species nested near the Audubon banding station 2010-2011.

Appendix Q. Those surveys are next to useless – 12 point counts (of unknown duration), conducted one week apart, in June, six years ago, in no way provide any semblance of an adequate bird study. The bird breeding season lasts from February (owls) through early September (goldfinches, hummingbirds). The counts obviously record no migrants or wintering birds. The counts even failed to survey one important habitat – grasslands. The “Trees” component combined at least two different habitat types (mature and developing; like averaging grapes and grapefruits).

This deficient “study” provides a totally inadequate basis for Table 3-3.

The Point Count results contain anomalies such as, in the “Wetlands,” a range of species from pelicans to flickers to orioles; no water birds except one White Pelican; Double-crested Cormorant on the list, but with all zeros both days. In the “Trees,” failure to detect several species known to breed in the Project Area: Great Horned Owl, Eastern Kingbird, White-breasted Nuthatch, European Starling, Bullock’s Oriole, and Lesser Goldfinch. Table 3-3 added the owl even though it failed to detect it.

4. Engineered riparian forests

When the Corps tried to mitigate the original Chatfield dam, it made a similar effort. The result: the pitiful set of trees between the scuba-diving gravel pit and Wadsworth Blvd. (just south of the perimeter road). That effort in no way did, or probably ever can, replace the mature cottonwoods destroyed by the reservoir. The beefed-up proposal posits irrigation, but apparently lacks water rights to carry out this proposition.

5. Proposed Mitigation Sites

Appendix K promotes mitigation for loss of the mature cottonwood forest by planting trees in grasslands adjacent the Platte and Plum Creek.

  • Soil conditions differ between upland grasslands and bottomlands; bottomland soil is moister and more organic.
  • The largest single mitigation site (Spr 1, Fig. 15 App. K) lies next to a densely packed, lake-side copse of scrawny cottonwood trees. This patch sprouted since the reservoir filled and provides no significant bird habitat.
  • How long would it take for this plan to “mitigate” the loss of the mature forest by producing a new one?
  • The other small sites would not contribute significant habitat even if they did develop into mature trees, because they are so small and scattered.
  • The Deer Creek sites would envelop existing wetlands. (I understand that these wetlands exist as mitigation for C470; can a second project commandeer a previous mitigation site?)
  • Several other South Platte sites (Spr 3 to Spr13) also envelop existing wetlands. Do those losses require mitigation?

Other sites (e.g. Spr 2) occupy grassland spaces between sections of forest – which destroys the mosaic that developed naturally. That mosaic provides feeding habitat for species that live in the cottonwoods (prey species live in such sites). (See, e.g., page 4-82: “Many raptors prefer grasslands when hunting. As upland areas become flooded, these forage areas would be lost, thereby reducing the available grasslands for raptors to hunt.”) These grasslands differ from the upland grasslands that surround the reservoir, in species composition, soil characteristics, and wildlife.

6. Tree removal.

If, as the report states, “It is unlikely that the pool elevation of 5,444 feet msl would be maintained for long periods of time” (4-81) then it seems senseless to clear cut that area.

I propose, that if you adopt Alternative 3, you revise your treatment of the South Platte corridor so that you do not cut down the trees upstream of Kingfisher Bridge. This would protect the best riparian habitat in the project (indeed, in the entire park). With the uncertain pool level, it’s quite possible that these trees would survive.

Yours truly,

Hugh E. Kingery

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