Little Butte BasinScout
The Freshwater Trust (TFT) and its partners completed a comprehensive geospatial assessment of the riparian lands within the Little Butte watershed of the Inland Rogue basin. The assessment is designed to identify the most cost-effective areas to target outreach and funding for agricultural BMPs that directly benefit water quality in Little Butte Creek.
This story map compiles geospatial layers in the Little Butte Creek Watershed and introduces users to watershed characteristics, including modeled environmental uplift potential for sediment and nutrient runoff. Map layers may be useful when selecting sites for possible irrigation upgrades and riparian restoration.
Watershed Context
Watershed Context
Little Butte Creek watershed boundary, with the major streams and canals shown. Little Butte Creek confluences with the Rogue River at Touvelle State Park opposite Upper Table Rock.
There are 11 major subwatersheds (12 digit HUC) within the Little Butte Creek watershed. Local partners identified seven tributaries of interest: Antelope Creek, Nichols Branch, Bitterlick Creek, Lake Creek, Salt Creek, and the North and South Fork Little Butte Creeks.
Areas under agricultural production, including hay and pasture, are shown here. Irrigation is common in the basin with most irrigated fields being flood irrigated.
Agricultural or pasture fields within 1,500 ft of streams and canals, shown here, were digitized and used for sediment and nutrient runoff analysis. 1,500 ft was determined by local partners to be a good perimeter for measurable impact of field runoff and bank erosion.
Riparian Uplift Potential
Priority riparian areas were identified for equal area units, called Riparian Area Units (RAU), along majors streams. Project participants determined RAUs would be 25 meters long and 5 meters deep.
Red RAU represents bank slopes of greater than 30%.
Green RAU represent areas that have less than 25% vegetation cover.
Pink RAU represent bank slopes greater than 30% and vegetation cover of less than 25%. These RAU have been highlighted as high risk riparian areas.
Sediment and Nutrient Uplift Potential
This map shows potential sediment "uplift", i.e. reduction in sediment runoff into Little Butte if all flood irrigated fields were in hay production and irrigation practices were converted from flood to sprinkler.
This map shows sediment uplift potential if all flood irrigated fields were in pasture and irrigation was converted from flood to sprinkler. Fields adjacent to streams were modeled with the assumption that livestock were present and could access the stream.
This map shows phosphorus uplift potential if all flood irrigated fields were in hay production and irrigation was converted from flood to sprinkler.
This map shows phosphorus uplift potential if all flood irrigated fields were in pasture and irrigation was converted from flood to sprinkler. Fields adjacent to streams were modeled with the assumption that livestock were present and could access the stream.
This map shows phosphorus uplift potential if all fields were in pasture with livestock present and livestock exclusion structures were added to fields adjacent to streams.
This map shows nitrogen uplift potential if all fields were in hay production and irrigation was converted from flood to sprinkler.
This map shows nitrogen uplift potential if all fields were in pasture and irrigation was converted from flood to sprinkler. Fields adjacent to streams were modeled with the assumption that livestock were present and could access the stream.
Nitrogen uplift potential if all fields were in pasture and livestock exclusion structures were added to fields adjacent to streams.
Combined Score Prioritization
Each of the NTT results layers were scored and combined. This was repeated for riparian priority (RAU) scores. The final prioritization is represented here by taxlot. Feel free to explore these layers.
Prioritization Distribution by Watershed
The distributions of prioritization scores in the graph below were created by taking from each subwatershed that has more than ten agricultural fields. Each dot in the graph represents a single random sample, and its location along the x-axis shows the sum of the prioritization scores of the ten fields randomly selected in that particular sample. The vertical dash in the middle of each cluster of points shows the mean value of all 500 sampling events for each subwatershed. ___
The distributions of prioritization scores in the graph below were created by taking 500 random samples of 10 fields from each subwatershed that has more than ten agricultural fields. Each dot in the graph represents a single random sample, and its location along the x-axis shows the sum of the prioritization scores of the ten fields randomly selected in that particular sample. The vertical dash in the middle of each cluster of points shows the mean value of all 500 sampling events for each subwatershed.
Subwatersheds with clusters of points located further to the right side of the graph have a higher proportion of high priority taxlots (i.e., taxlots with high uplift potential) than subwatersheds with clusters located further to the left of the graph. Moreover, subwatersheds with points that are more tightly clustered have a lower variance (i.e., smaller difference between high values and low values) than those with points that are more spread out.
Below, the same random sampling procedure was used to create a plot of riparian area unit (RAU) prioritization scores by taxlot (as opposed to the NTT runoff prioritization scores by agricultural field shown in the plot above).
Note that this plot does not include Salt Creek because there were too few RAUs analysed in this subwatershed for this analysis.
Explore Watershed Layers Further
This project wouldn't be possible without the support and collaboration of the following partners...
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Medford Water Commision
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Rogue Basin Partnership
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Rogue River Watershed Council
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Jackson Soil & Water Conservation District
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Trout Unlimited
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USFS Rogue River-Siskiyou National Forest
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BLM Medford District Office
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