Maps
Heritage reviews are conducted by
overlaying various kinds of records over the United States Geologic Survey
(USGS) 7.5 minute topographic maps. This makes the "topo" preferred as a site locator map, although other
maps will in many cases work. The important thing is that the map you
provide enables our staff to locate your project site on the topographic
map. County highway maps often show too little detail to relate to the
terrain, and the roads plotted on the two forms do not always line up well.
Maps can be a problem for many
people to find, copy and mail. One
solution is to find maps at on-line sites, especially one of the several sites
that provide USGS maps on-line. Maps for
heritage review need to make it possible to identify a project site clearly,
but sharp detail in describing project boundary is not necessary – hand-drawn
pinpoints or site boundaries on a printed portion of a topographic map sheets work fine (but please be sure to
identify the name of the map quadrangle).
Because of limited storage options at the Department of Conservation, we
cannot retain large maps on file for future reference.
On-line tools:
► TerraServer is an online commercial mapping
service with some useful services available at no charge. Located at http://www.terraserver.com/, you can use
it to easily find a location (e.g. a topographic or photo map of a town). Once you have found the site, the site
reports latitude and longitude coordinates as you move the cursor over the
map. Terraserver
will also provide an email link (URL) that you can e-mail to provide reviewers
the ability to look at the same map.
Printable maps require payment of a fee.
► The CARES (Center for Applied Research and
Environmental Systems) Map Room is a free service at http://maproom.missouri.edu/. It will enable you to construct topographic
or photographic background maps and identify coordinates or print maps of
► The USGS operates the National Map Viewer at
http://nmviewogc.cr.usgs.gov/viewer.htm. It allows you to view, navigate and print
maps with a variety of backgrounds, or identify latitude/longitude coordinates
for the point covered by your cursor.
Site Location
Heritage reviews require, in
addition to a map, the name of the county and definite site location
information. One good locator is the Township, Range and Section (T/R/S),
available on many deeds and legal descriptions of real estate. T/R/S works well with our mapping tools to
locate project sites in most of the state. Somewhat greater precision is
available with either UTM coordinates
or latitude and longitude. Street
addresses do not work well to locate points on topographic maps, which
typically show few street names and no numbering system.
UTM: Universal Transverse Mercator is a
framework for locating sites on a type of map called a Mercator
Projection -- topos are
among them. It basically counts meters to a point from two fixed
baselines, and is usually more reliable for pinpoint precision. Most GPS
receivers, increasingly common today, identify locations base on UTM coordinates. Most of
Lat/Long: Latitude and Longitude are angular
measures. Latitude measures degrees
north of the Earth's equator while longitude measures degrees east or west of
the Prime Meridian that passes through
On-line
Coordinate Converters: There
are tools available on-line that allow conversion among the T/R/S, UTM and Lat/Long systems. Here are
two: Degree/Minute/Second
to Decimal Degree Converter and Latitude/Longitude
to UTM Converter
Mapping errors
Mapping systems and coordinate
systems do not always work in precise unison, and this is one reason we look
not only on your project site but in a one mile radius about it. Aside from
error in measurement (e.g. GPS error, or round-off errors, like 39.2 v. 39.175
v. 39.174 degrees), one point identified by both UTM
and Lat/Long on-site may show up on a map as two different points many meters
apart.
Mapping errors affect your data on
site location, and our data on endangered species sites. When our map
shows a species record on your site, it may in fact be some distance
away. On the other, hand, we may see a species record that appears to be
several hundred yards distant, but in fact was recorded on your project
site. This is part of the reason every
heritage review letter should be viewed as a beginning point that project
planners need to analyze appropriately and confirm on the ground.
Remember, laws protecting species
and habitats of conservation concern assign responsibility to the project and
its managers. A heritage review is one action toward that end, but it is
only a source of information. It is our goal to help you comply with laws
and regulations by identifying known or likely issues you may have to resolve,
and suggesting ways to complete your project with minimal impact.
We believe it is better to remind
you that a concern may be present than to omit reference and end up with an
emergency when "the dozers start moving." For example, we may
alert you to the possibility of karst geologic features (caves, springs,
sinkholes) at a site. If you know no such features are there, there is
nothing that needs to be done. If there
are karst features, it is worth special planning to avoid impacts to
groundwater, not to mention the needs of rare cave species and the legal
implications of impacts to them.