Damonte Ranch Wetlands Earthcache
Wetlands are generally considered to be areas of land whose
soils are saturated with moisture either permanently or seasonally.
The official definition given by the United States Army Corps of
Engineers (COE) and the U.S. Environmental Protection Agency (EPA)
are ”those areas that are inundated or saturated by surface
or groundwater at a frequency and duration sufficient to support
and that under normal circumstances do support, a prevalence of
vegetation typically adapted for life in saturated soil” (COE
1987). Wetlands generally include swamps, marshes, bogs and similar
areas and can be created by fresh or salt water or any combination
thereof. This discussion will mostly be limited to the freshwater
type. Since the 18th century it is estimated that more than half of
the original 220 million acres of wetlands in the US have been
degraded or destroyed, for such purposes as conversion to
agriculture, real estate development and flooding during reservoir
construction (EPA 2004).
Geology and Wetland Landscapes
Wetlands can develop only in regions where water accumulates,
meaning that the ground under the wetland must be impervious to
water. Underlying geology provides the base on which wetlands can
form. This includes the softer materials such as silt, clay, and
charcoal that can be deposited over the parent rocks below. The
form of the landscape also has an effect on wetland development.
The illustration below shows how wetlands are most likely to be
found in valleys or hollow spots in the general landscape.
The first kind (shown in the top illustration is called
topogenous. This kind depends on the shape and form of the
landscape. This is the most abundant type. Especially found where
precipitation is low and water gathers from a wider source. Damonte
Ranch Wetlands is this type of wetland.
The second type (shown in the middle) is called soligenous. It
is close to the same type as the first, except that it is formed by
ground water emerging from the ground through porous water-laden
rocks till it meets impervious rocks below. The water then forms
springs that feed the wetland. This type of wetland is only found
where two very different types of rocks come together.
The third type (shown at the bottom) is a floodplain wetland. It
is usually formed in the lower parts of river valleys where the
river has often overflowed its banks. The waters from these floods
spread out over the floodplain and form the wetlands. The sediments
in the flood waters fertilize these regions and make them very
fertile for farming. [citation: Science
Online: Geology of Wetlands]
Wetlands have three critical criteria, hydrology, soils, and
hydrophytic vegetation . Without these the entire wetland ecosystem
would collapse. Hydric soils are the building blocks for wetlands
and are present in the landscape primarily due to the geology and
hydrogeology of the region.and plays a
critical role in wetland dynamics (Warner 2004). Furthermore,
wetlands are closely connected to their individual basins and to
their watersheds. Soils that are saturated due to surface or
groundwater (flooding, ponding or shallow groundwater) during the
growing season develop anaerobic conditions (lacking oxygen) in the
upper layer and support hydrophytic vegetation adapted for life in
saturated soil conditions. Terrestrial plants, as opposed, to
hydrophytic ones, require oxygen in the soil to grow
Geology of the Truckee Meadows effects distribution of
precipitation, depth to groundwater and runoff patterns. And
further, hydrology of a region is the most important factor in the
development of hydric soils. Truckee Meadows, located in Reno,
Nevada, like the majority basins in the Basin and Range
Physiographic Province, is a depression bounded by fault-block
mountains (Huntington USGS undated ) The Carson Range to the west
is composed of metavolcanic and metasedimentary rocks that are
intruded by granite. These formations are overlaid by tertiary
volcanic rocks of mostly rhyolite and andesite, The Virginia Range
to the east is similar in geology except the granitic rock is
overlain by extrusive rocks. Basin-fill deposits are generally
divided into three geologic units, sedimentary rock of tertiary
age, older alluvium of quaternary age and younger alluvium of
quaternary age. The Carson Range to the west of the Basin is
responsible for the development of an alluvial fan composed of
silt, sand, gravel, and boulders. Alluvial deposits are also
present along the major streams in the basin; Truckee River and
Steamboat Creek, and along stream channels of tributary drainages.
Recharge to the basin aquifer is thought to be from five major
sources. The majority, about 64%, comes from mountain front
recharge, primarily from the Carson Range.. Of secondary
importance, about 26%, is derived from infiltration from streams,
excess irrigation water, canal seepage, public supply lines and
urban lawn watering (Huntington USGS undated ). Therefore, this
pattern of recharge would suggest groundwater generally flows from
the west and south toward the Truckee River and Steamboat Creek and
discharge areas in the center and eastern parts of the valley. The
Damonte Ranch development is located within the historic Truckee
Meadows and the Damonte Ranch area is generally considered to be in
a discharge area with shallow groundwater that historically
supported wetlands prior to historic (pre-1900's) conversion of
land for ranching and farming purposes.
Values and Functions of Wetlands
Wetlands are very valuable for the region and watershed in which
they exist. A watershed is an area of land in which the surface
water converges to a single point. The Truckee Meadows is in the
Truckee River watershed which begins at Lake Tahoe and ends at
Pyramid Lake. Within the Truckee River watershed there are many
sub-watersheds such as the Steamboat Creek watershed.that begins at
Washoe Lake and ends at the Truckee River near Vista and is the
largest tributary to the River downstream from Reno. The Truckee
River basin is quite unique in that it is considered endorheic,
which means that it does not drain to an ocean. Instead, it drains
to an inland basin, Pyramid Lake. Only 18% of all land drains to
endorheic lakes or inland seas. Because these lakes have no outlet,
evaporation is the primary means of water loss and they tend to
become saline. The message here is that everything we do upstream
effects everything downstream. In the past 150 years or so, man has
made a huge impact (detrimental) on the Lake Tahoe-Truckee
River-Pyramid Lake water quality and ecosystems.
Wetlands do more than provide habitat for plants and animals.
The following describes the various
functions of a wetland:
- Water Quality: As water flows through a wetland it flows more
slowly and moves around and through the plants and has contact with
the soil.. This has many benefits to the quality of the water. As
the water slows sediment drops out and settles to the bottom.
Nutrients such as nitrogen and phosphorus, that cause algae to grow
downstream, are removed with the sediment, or absorbed by the
plants and microorganisms in the soil. Wetlands are so efficient at
this function that some municipalities are constructing artificial
wetlands to treat wastewater and stormwater. Another way wetlands
filter water is their capability to remove harmful bacteria.
Invertebrates that live in the wetland, such as aquatic insects,
feed on bacteria. One study showed that up to 90% of the bacteria
entering a wetland were removed by the time the water left the
wetlands (EPA 2010). Other studies have found that the oils
and
heavy metals that drain off of streets with stormwater can also be
treated by passing through a wetland. Steamboat Creek has been
designated by the State as impaired, meaning that it is not meeting
the water quality standards set to protect it's various uses. This
water eventually makes it's way into the Truckee River and Pyramid
Lake. Pyramid Lake has its own water quality standards. Pyramid
Lake supports two fish that are threatened and endangered, the
Lahontan Cutthroat Trout (Oncorhynchus clarki henshawi) and Cui- ui
(Chasmistes cujus), respectively. Secondly, Pyramid Lake has no
outlet, so a contaminant that enters the Lake will never be flushed
out. Restoration projects on Steamboat Creek, such as the DRW will
improve water quality downstream within the watershed.
- Water Storage: Wetlands act like natural sponges in that they
absorb the water that enters and then gradually release it very
slowly over an extended period of time. This process provides an
important benefit during a flood, as the water is released from the
wetland after the peak flood-flows have passed, thereby reducing
the damaging effects of the flood . Flood control is a major issue
in the Truckee Meadows at
the present time and millions of dollars will soon be spent in
order to lessen the impact of these events that have been regularly
occurring about every 10 years. Related to this function is a
reduction of erosion which damages stream channels and increases
sediment load. It also increases groundwater recharge and
contributes to base flows, which is especially important during dry
years.
- Habitat for fish and wildlife: Wetlands are considered to be
one of the most biologically productive ecosystems in the world,
comparable to tropical rainforests and coral reefs (EPA 2001)..
They are home to one the largest collections of biodiversity to be
found on the planet (www.articlemyriad.com), representing reptiles,
amphibians, fish, birds and mammals. Large numbers of both
terrestrial and aquatic organisms rely on wetlands for some phase
of their life cycle. A large variety of migratory birds, breed,
rest, and feed in these areas More than one-third of the threatened
and endangered species in the US live only in wetlands, and nearly
half use wetlands at some point in their lives (EPA 1995). Most
commercial and gamefish breed and raise their young in coastal
marshes and estuaries. Important species of fish you may have heard
of that use wetlands include Menhaden, Flounder, Sea Trout, Spot,
Croaker and Striped Bass. Likewise, shrimp, oysters, clams, and
crab need these wetlands for food, shelter or breeding. Wetlands
are so important that an international agreement was developed
because some species of migratory birds are completely dependent on
certain wetlands.
History and Description of Damonte Ranch
Wetlands
In the United Sates wetlands are regulated under section 404 of
the Clean Water Act (CWA). In general terms, section 404 comes into
play when there is going to be the placement of dredged or fill
materials into waters of the United States (wetland) or filling of
a wetland. The CWA states that any discharge of dredged or fill
material into “waters of of the United States, including
wetlands, is forbidden unless authorized by a permit issued by the
COE persuant to section 404”.
In this case, DiLoreto Construction began work on Damonte Ranch
in 2003, and is a 1,743 acre mixed use development in Southeast
Reno approximately 6 miles from downtown Reno. Of the total
acreage, 1,047 acres is residential, 37 acres of town center, 193
acres of office/industrial, 80 acres of public/semi-public
facilities , 110 acres of park and recreation and 276 acres of open
space and wetlands. A very popular trail system winds throughout
the entire development.. It was determined that jurisdictional
waters (wetlands) would be impacted by the development and would
therefore require a 404 permit. 7Q10, a local environmental
consulting firm, was hired to take responsibility for working with
the regulatory agencies (federal, state and local) in developing
and implementing all aspects of the 404 and 401 permits. In the
process 7Q10 has collected hydrological data, defined soil
characteristics, defined vegetation associations (including
invasive species), and identified and enumerated avian use and
diversity.
As part of the mitigation plan and to meet requirements of the
404 permit, 173 acres of wetlands
have been created, enhanced or both. The main wetland area was
deepened to take advantage of shallow groundwater such that the
wetlands are almost always permanently flooded. This is consistent
with the hydrogeology of the area as described in an earlier
section. Other sources of water include storm water runoff from
adjacent streets and roadways. Agricultural runoff from fields to
the south occasionally flow into a detention basin.
In conclusion, I would like to make the following observation.
People either hate or applaud new developments and it is well known
that they are good for the local economy. I live in Reno and grew
up in Winnemucca and Fallon and have seen the results of
developments done well and poorly. I hope that this earthcache
draws more people to see the work accomplished at Damonte Ranch
Wetlands and I think that you will agree the developer and their
team produced something special, both in terms of economics, but
also social and environmental.
To Log this Earthcache
Answer the following questions and email the answers to the
developer of the site. Please remember basic visitor use and public
safety Information for Public Lands in Nevada available at http://www.treadlightly.org or
http://www.int.org
Remember to stay on the established pathways and out of the
wetlands!
- Question 1: Based on what you see from the posted coordinates,
which of the three types of wetlands shown in the image in the text
would you say this one is?
- Question 2: From a geological perspective, what is the thing
that you cannot see (at most locations) that is probably the most
important component of this and all wetlands and why is it so
important?
- Question 3: For this question you will have to go to the
parking waypoint #3. This is where Steamboat Creek enters the
wetland and with the 5 storm drains are the major sources of
pollution delivered to the wetland. Look around and identify the
major land uses in the area. As water runs off these areas you have
identified, it has the potential to carry pollutants into the
wetland. Name 3 pollutants that can enter the wetland from these
sources/areas.
References:
Huntington, J.M. (undated manuscript). Section 3. Conceptual
understanding and groundwater quality of the basin-fill aquifer in
Truckee Meadows, Nevada. in: Conceptual understanding and
groundwater quality of selected basin fill aquifers in the
southwestern United States. Professional Paper 1781. U.S. Dept. of
Interior, U.S. Geological Survey
Moore, Peter D. "geology of wetlands." Wetlands, Biomes of the
Earth. New York: Chelsea House Publishing, 2006. Science Online.
Facts On File, Inc.
U.S. Army Corps of Engineers. 1987. Wetland Delineation Manual.
Wetland Research Program Technical Report Y-87-1 (on-line
edition).
U.S. Environmental Protection Agency. 1995. American Wetlands:
Our vital link between land and Water. Office of Water, Oceans, and
Watersheds. EPA 843-k-95-001.
U.S. Environmental Protection Agency. 2001. Function and values
of wetlands. Office of Water, Office of Wetlands, Oceans, and
Watersheds. EPA 843-F-01-002.
U.S. Environmental Production Agency. 2004. Wetlands Overview.
Office of Water. EPA 843-F-04-017a.
Warner, G.W. 2004. Geology of Canadian Wetlands. Geoscience
Canada. Geological Association of Canada. June 2004. 13pp.
I would like to thank Lori Carpenter, hydrologist at 7Q10, who
provided her groups data, reviewed and thoroughly marked up the
draft and confirmed the accuracy of the paper.
Congratulations to randallh for being the First to Find.