The Rainwater Basin in Nebraska
Steve Moran, Maggie Smith
Abstract:
Defining Issue: Developing Resource Inventories to help landowners and agency specialists develop a watershed plan which addresses wetland management as part of an integrated surface water management plan.
GIS Solution:
The Trumbull Basin watershed planning effort was initiated by
the Rainwater Basin Joint Venture to discuss the restoration of
migratory waterfowl habitat on previously drained cropland. The
farmers and landowners agreed to participate in the plan development
if the objectives were expanded to include the issues of flood
control, supplemental irrigation water, erosion control, farm
economics, and social issues dealing with communication between
neighbors.
An inventory of watershed
resources was the first request of the planning group. GIS technology
was used as the best way to show the spatial relationship and
inter-relationship of the inventoried resources. Those items inventoried
included elevation surveys, land use, soils, potential shallow
water habitat, surface water storage facilities, hydrologic drainage
patterns and aerial photography.
Maps prepared with GIS
technology were the primary planning tools. Organizing and manipulating
data which was then used as a visual tool proved to be beneficial.
In addition to information, the maps served as catalysts to individual
landowners discussing issues as a watershed community rather than
individually.
Hot Links using pictures
of the landscape, potential wetland sites, and surface water storage
facilities were used to acquaint non-local agency specialists
and administrators with the watershed features.
The Spatial Analyst module
depicted shallow water wetland sites as areas below specified
elevations at particular locations.
The completeness of the
inventory and GIS technology allowed alternative development by
the landowners which addressed combined issues rather than individual
situations. The inventory helped biologists, engineering specialists,
planners and landowners discuss proposals which were based on
factual rather than assumed information.
The landowner decisions
and Best-Management Practice locations will be documented using
GIS. Follow-up and plan implementation progress will be shared
using maps and tables produced with GIS.
Software: TerraModel
software was used to develop stage storage capacities of shallow
water wetland habitat sites and surface water storage sites. Arcview
3.0 and Spatial Analyst were used as mapping software to designate
shallow water boundaries on a DOQQ base. Microsoft PowerPoint
used images created in Arcview for presentations.
The Trumbull Basin Surface Water Management Plan was initiated when the Rainwater Basin Joint Venture approached landowners of a converted wetland basin, and asked if they would consider managing spring runoff to create areas of shallow water habitat for migrating waterfowl. Their response was,
"We'll help you with 18 inches of water in the spring if you'll help us deal with the 2 feet that comes in July!"
This was the basis for a beginning. The planning effort has assembled engineers, conservationists, biologists, and regulatory specialists from state, federal and local agencies to support the planning process driven by local participation. The effort has integrated water issues dealing with wetland habitat, irrigation water management, erosion control and flood control. Perhaps most important, the process has provided a communication avenue where landowners could overlook past animosities and grievances to cooperatively address common problems. As one landowner said,
"We know the solution to our problems are simple if we could just sit down and talk about them. If you can help us talk to one another, we're interested."
The Trumbull/Hansen Basin
is located in northeast Adams County in South Central Nebraska.
The basin is essentially an 1800 acre oblong windblown depression
lying north-south in the landscape. Runoff from the upland landscape
ended up in the lowest elevations of the basin bowl with the bottom
of the bowl being 500 acres in size. Once the water level in the
basin gets high enough it spills out the southeast side of the
basin and travels two miles to the West Fork of the Big Blue River.
The Rainwater Basin in Nebraska
Long ago, the bottom
of the basin was a 400 acre semi-permanent and permanent wetland.
Extensive modifications in the basin have been done to convert
much of the wetland area to cropland. Landowners have built dikes
to direct water and built above ground storage pits to store water
pumped from cropland areas. Eight landowners farm in the basin
bottom. Each has methods to deal with the water that runs onto
their property, but there is no comprehensive strategy to deal
with the water. When the watershed is hit with a large rain, crops
are flooded because there is limited storage and little opportunity
to move water through the basin. Downstream landowners have erosion
and field saturation problems from prolonged flow of overflow
runoff.
An inventory of watershed
resources was the first request of the planning group. Geographic
Information Systems (GIS) technology was used as the best way
to show the spatial relationship and inter-relationship of the
inventoried resources. Those items inventoried include elevation
surveys, field boundaries, soils, potential shallow water habitat,
surface water storage facilities, hydrologic drainage patterns
and aerial photography.
Elevation Map
Field Boundaries Map
Soils Map
Shallow Water Habitat and Surface Water Storage Areas
Maps prepared using GIS
technology were the primary planning tools. The maps proved to
be informative, as expected, and also served as catalysts to individual
landowners discussing issues as a watershed community rather than
individually. Planning participants recognized the inter-relationship
of the issues discussed and volunteered historical information
important to the inventory.
The first maps used for the meetings were Digital Ortho Quarter
Quads and quadrangle map TIGER files. A land ownership layer and
hydric soil layer were shown with the TIGER data. These maps served
as focal points for informal discussion between people who had
not spoken to each other in years. The water management issue
had been divisive to the landowners. Discussions about information
portrayed on maps began to establish the communication links needed
for progress. An elevation survey was conducted and a topographic
map developed in Terra-Model Design Software. The elevation map
was saved as a .dxf file. The file was then georeferenced and
inserted into the project file as an elevation layer. Again, the
elevation map produced considerable discussion about the basin.
While the contours confirmed what the landowners intuitively knew,
it began to bring discussions from conceptual opinions and observations
to factual alternatives.
Biologists selected potential shallow water habitat sites based
on soils and contours. Existing deep water storage facilities
were measured for storage capacity. GIS products displayed the
shallow water areas, capacities, and anticipated runoff. These
volumes were compared to adjacent surface water storage facilities.
Hot Links using pictures of the landscape, potential wetland sites,
and surface water storage facilities were used to acquaint non-local
agency specialists and administrators with the watershed features.
Shallow Water Habitat Area Hot Linked
Similar wetland management
projects have been implemented in south central Nebraska in the
past. Without the use of GIS as an information tool, success has
been minimal. Agency specialists and landowners need the ability
to envision the big picture and discuss planning and solutions
which cross property boundaries. Without GIS, this can be difficult.
People define problems and develop solutions based on the knowledge
they have. This knowledge is usually limited to their experiences
and observations with their own property. GIS products allow people
to step back from those tracks of lands they are familiar with
and look at what is happening on neighboring ground that impacts
their own situation. ArcView3.0 and other GIS software allow the
mass amount of tables and maps to be organized, analyzed and manipulated
according to the needs of the project. The Trumbull Basin project
is considered a success because the cooperating partners looked
at integrated solutions which crossed property lines. In addition,
the GIS products served as catalysts for communication between
landowners who had not spoken in years. GIS built communication
channels which allowed watershed planning.
The GIS tools used for
the planning process were critical in having landowners look beyond
property lines to solutions on neighboring ground. The effort
grew to a watershed management plan by a recognition of water
flowing downhill. Integrating solutions occurred when landowners
had tools to understand what happened to the water before and
after it flowed across their land.
By combining products of engineering software, GIS maps, and local
expertise, decisions were based on factual information and alternatives.
The Rainwater Basin Joint Venture objectives were not to have
all the farmers make a "yes" decision for wetlands,
but to make informed decisions about resource management.
The lessons learned from Trumbull Basin, the GIS processes and
products, are being used for other watersheds in similar ways.
The difference between projects where GIS was used as an information
tool and where it wasn't is stark. Trumbull Basin has served as
an example to accelerate GIS implementation throughout south central
Nebraska.
Steve Moran
Rainwater Basin Joint Venture Coordinator
USDA-Natural Resources Conservation Service
Grand Island, Nebraska 68803-1333
Telephone: (308)385-6465
Fax: (308)385-6469
Maggie Smith
GIS Specialist
USDA-Natural Resources Conservation Service
2550 N. Diers Rd, Suite L
Grand Island, Nebraska 68803-1214
Telephone: (308)382-0814
Fax: (308)382-3688