HomeMy WebLinkAboutSANCTUARY ON THE GREEN - PDP210018 - SUBMITTAL DOCUMENTS - ROUND 3 - ECS REPORT
Technical Memo
PO Box 272150,
Fort Collins, CO 80527
(970) 988-3106
Date: February 28, 2022
To: City of Fort Collins
From: Cedar Creek Associates, Inc.
Subject: Sanctuary on the Green Ecological Evaluation
Introduction
Cedar Creek Associates, Inc. (Cedar Creek) was requested to evaluate the potential impacts to avifauna
from the proposed Sanctuary on the Green development site. The proposed development property is
located on the northwest corner of Laporte and Taft Hill and is bisected by New Mercer Ditch. An
Ecological Characterization Study was authored by Cedar Creek and described the natural features and
habitat located on and immediately adjacent to the development property. The purpose of memo is to
define a wildlife concentration area as it applies to the City of Fort Collins Land Use Code and determine
whether the natural features on the development property exhibit characteristics of concentration areas.
An important distinction to be made is the difference between general wildlife habitat and a concentration
area or key use area. Concentration areas for wildlife are generally defined as having a significantly
higher density of use than within the species overall range, and/or areas in which densities are at least
200% greater than in the surrounding overall range during a specific season (CPW 2014). General
habitat could be suitable for species breeding, foraging, and nesting, but may not exhibit the density and
typical characteristics of a designated concentration area.
City of Fort Collins Land Use Code
The City of Fort Collins Land Use Code defines nesting waterfowl concentration areas, migratory
shorebird concentration areas, nesting shorebird concentration areas, and migratory songbird
concentration areas as special habitat features that require a 300-foot buffer. As per Section 5.1.2,
special habitat features, including key production areas, wintering areas and migratory feeding areas for
waterfowl; key use areas for wading birds and shorebirds; heron rookeries; key use areas for migrant
songbirds; key nesting areas for grassland birds, are identified and delineated by Colorado Parks and
Wildlife (CPW) or City of Fort Collins Natural Areas Department (NAD).
· Migratory waterfowl concentration areas - 300 feet
· Nesting waterfowl concentration areas - 300 feet
· Migratory shorebird concentration areas - 300 feet
· Nesting shorebird concentration areas - 300 feet
· Migratory songbird concentration areas - 300 feet
The City of Fort Collins Land Use Code also provides buffer distances for other natural features, such as
irrigation ditches that serve as wildlife corridors (50 feet) and wetlands less than 1/3 acre in size (50
feet).
City of Fort Collins Natural Areas Department Background
The City of Fort Collins NAD policy plan (NAD 1992) clearly defines key wildlife sites or concentration
areas as follows:
1. Concentration areas for raptors (large prairie dog colonies, large lakes, the foothills, and the
Poudre River Corridor);
2. Key sites for migrant songbirds (Spring Creek Outlet, north end of Dixon Reservoir, north shore
Warren Lake cottonwood stand, Poudre River Corridor, and Grandview Cemetery);
3. Great blue heron rookery (located along Poudre River, south of Northern Colorado Environmental
Learning Center);
4. Key duck production areas (Poudre River and adjacent ponds, some of the larger lakes);
5. Duck winter concentration areas (Poudre River south of Mulberry and some of the larger lakes);
and
6. Areas of high terrestrial or aquatic insect diversity (Fossil Creek, Spring Creek Outlet, and along
the Poudre at McMurry Nature Area, Lee Martinez Park, and Northern Colorado Environmental
Learning Center).
The Sanctuary on the Green project site is not identified in that report as any of these key wildlife sites or
concentration areas.
The City of Fort Collins NAD provides guidance in its Wildlife Conservation Guidelines (NAD 2017) that
can assist in defining a concentration area’s habitat characteristics. These guidelines define concentration
areas or key production areas as gravel ponds, the Poudre River and the wetlands adjacent to the river.
These areas are of particular importance during the spring migrations as ducks and shorebirds frequently
use these seasonally flooded wetlands that are rich in food resources. This provides carbohydrates for
migration and invertebrates for the formation of protein necessary for egg production for breeding
species.
Sanctuary on the Green has none of the above habitat concentration characteristics, nor is there any
evidence of a significant concentration of waterfowl and shorebirds.
Colorado Parks and Wildlife Background
CPW provides publicly available data on species activity mapping (SAM) for the entire state of Colorado.
In this dataset, individual species known overall range, nest locations, concentration areas, and migration
corridors among several other species-specific characteristics are compiled. Each term used to delineate
species occupancy is defined by CPW (CPW 2014). CPW does not delineate concentration areas for all
species of waterfowl but does provide a precedent for defining what seasonal concentration densities
entail:
Concentration areas for wildlife are generally defined as having a significantly higher density of use
than within the species overall range, and/or areas in which densities are at least 200% greater
than in the surrounding overall range during a specific season (CPW 2014).
Concentration Area Habitat Characteristics
Guidance documentation from CPW and NAD can help to define the typical habitat characteristics of a
concentration area or key use area. Typically, existing waterfowl concentration areas are centered around
perennial bodies of water, reservoirs, river corridors and natural areas. These areas provide suitable
habitat that supports large flocks of waterfowl or shorebirds. To sustain such populations, concentration
areas must contain a large invertebrate prey base, diversity of shoreline and aquatic vegetation, and
quality cover for nesting (NAD 2017).
Important features to consider when rating habitat quality include:
1. Acreage, average water depth, and seasonal duration of open water;
2. Shoreline vegetation, aquatic vegetation (percent emergent and submergent), and shoreline
configuration;
3. Availability of invertebrate and vertebrate food base;
4. Amount and quality of habitat for nesting or cover; and
5. Proximity to human activity.
As part of Colorado’s State Wildlife Action Plan (CPW 2015), CPW declared several species priorities for
conservation. Fact sheets/ habitat scorecards were developed to describe species descriptions,
distributions, preferred habitat conditions, and management recommendations. The mallard, a waterfowl,
is a Tier 1 species in the State Wildlife Action Plan. The following table describes the preferred habitat
conditions for the mallard, these represent potential characteristics to
Dominant vegetation sedges, rushes, grasses, forbs, and aquatic vegetation
Density of plants desirable to ducks
abundant (desirable plants are often seed-bearing
species such as pondweeds, dock, sedges, and
some grasses)
Emergent vegetation within open
water
20–50% for diurnal use
60–80% for nocturnal use
Interspersion complex patterns that maximize interface between
water and vegetation
Landscape context proximity to other wetlands on the landscape
Size of habitat At least 20 acres for wet meadows
At least 10 acres for other wetlands
Submergent vegetation 30–60%
Water depth (predominant)
4–12 inches; during breeding
8–24 inches or deeper if submergent vegetation is
present
Nesting habitat
wetlands surrounded by at least 40 acres of treeless
upland habitat with ample residual cover and dense
vegetation, at least 10 inches in height
Project Site Evaluation
The field surveys conducted for the development of the Ecological Characterization Study did not reveal
elevated wildlife use with significantly higher density than that within the species overall range, and/or
areas in which densities are at least 200% greater than in the surrounding overall range during a specific
season. This finding is based on observational data.
A review of the CPW Species Activity Mapping data show no known concentration areas of any species
located within the proposed development site. Similarly, available data from Fort Collins NAD does not
identify any concentration areas for any species within the proposed development property.
The natural wetland and water features onsite do not exhibit the general characteristics of concentration
areas. The features are not large perennial bodies of water or river systems. In fact, riparian and wetland
systems on the project site comprise less than 2.5 acres. The shoreline vegetation along New Mercer
Ditch exhibits very poor diversity, which is primarily dominate by non-native grasses. The quality of
habitat for nesting and cover over most of the project site is limited due to the land management
activities of the agricultural fields used for hay production, which are cultivated each year. Finally, the
project area is heavily used by people and pets for recreation, both along the established recreation trail
to the north of the property and along New Mercer Ditch, which transverses the property. Based on these
factors the project site does not exhibit the general characteristics of a concentration area.
In addition, when considering the habitat preferences for mallards, the project site does not exhibit the
preferred habitat conditions, particularly because the wetland or water features onsite:
· do not exhibit an abundant density of plants desirable to ducks (seed-bearing species such as
pondweeds, dock, sedges, and some grasses);
· do not exhibit significant emergent vegetation within open water for diurnal and nocturnal use;
· do not exhibit interspersion with complex patterns that maximize interface between water and
vegetation;
· do not exhibit significant size (10-20 acres of wet meadows or other wetlands);
· do not exhibit submergent vegetation of 30-60%; and
· do not exhibit upland habitat with ample residual cover and dense vegetation, at least 10 inches
in height because of the agricultural activities.
The Ecological Characterization Study provided characterizations of the general wildlife habitat supported
by the non-native herbaceous, upland woodland, riparian (herbaceous and woodland), and wetland
vegetation communities located on and around the project site. The woodlands provide the most suitable
forage and nesting habitat for raptors and migratory birds, most of which of been identified for
mitigation. Several species of raptor have been observed utilizing the property as a forage area as well as
numerous migratory birds have been observed in the surrounding wetlands and along the New Mercer
Ditch. Given known occurrences of several migratory bird and raptor species, it is reasonable to conclude
the proposed development property provides general wildlife habitat, particularly with regard to the
wetlands as well as a corridor for wildlife along New Mercer Ditch. The appropriate buffer distances for
these inventoried natural features located on the project site were provided in Cedar Creek’s Ecological
Characterization Study and remain applicable. The lack of large perennial water and close proximity of
the proposed development to existing human activity limits the sites suitability as a concentration area for
nesting waterfowl and shorebirds. The lack of mature riparian vegetation combined with the current
habitat use consisting mainly of an actively managed monoculture agricultural field further limits
suitability for many ground-nesting migratory birds and waterfowl. Onsite visits and observations do not
indicate significantly higher densities of nesting waterfowl, shorebirds and migratory birds. Therefore,
Sanctuary on the Green proposed development site should not be considered a concentration area, key
use area, or similar for any species.
Flight Impacts
Potential impacts to the behavior and movement of wildlife, including the flight patterns of waterfowl, are
considered when applying buffers to natural features onsite. The Natural Habitat Buffer Zone facilitate
waterfowl movement, including takeoff and landing, by maintaining a reasonably undeveloped portion of
suitable habitat within the proposed development site. A review of available literature does not provide a
conclusive consensus on requisites for the extent necessary for waterfowl take off, nor does it provide a
regulatory framework for protecting such behavior. Given that mallard and other common waterfowl
species have adapted successfully to urban habitats, the proposed development site is not anticipated to
have a significant impact on flight patterns of waterfowl.
References
Cedar Creek Associates, Inc. (2019). Ecological Characterization Study.
Colorado Parks and Wildlife (CPW). 2014. Colorado Parks and Wildlife GIS Species Activity (SAM) Mapping
Definitions Publicly Available Data. December 10, 2014
Colorado Parks and Wildlife (CPW). 2015. State Wildlife Action Plan.
NAD 2019a The City of Fort Colins Natural Areas Department. Natural Habitats and Features.
https://opendata.fcgov.com/dataset/Natural-Areas/q5p4-p4hy
NAD 2019b The City of Fort Colins Natural Areas Department. Natural Areas.
https://opendata.fcgov.com/dataset/Natural-Areas/q5p4-p4hy
NAD 2017. The City of Fort Colins Natural Areas Department. Wildlife Conservation Guidelines.
https://www.fcgov.com/naturalareas/pdf/wm-guidelines17.pdf?1645719558
NAD 1992. The City of Fort Colins Natural Areas Department. The City of Fort Collins Natural Areas Policy
Plan. October 1992. https://www.fcgov.com/naturalareas/pdf/natural-areas-
plan.pdf?1389654171