Case Study - Meadow Creek

Design a restoration scheme for a channel component of a wetland mitigation project.  The existing channel is a straightened reach through a broad valley used for cattle grazing and farming.  This “impacted reach” is spring-fed and has become entrenched in a sandy soil.  It looks like a gully in many locations.  The restoration scheme selected for the wetland includes raising the channel bed into a slightly more gravely layer of soil while lifting the localized water table to increase support of aquatic plants and wetland habitat.  A small, spring-fed, E4 reference reach was observed in a farm field a few miles from the project site.  Use this reference reach to help design a restored, meandering reach in the Meadow Creek wetland project.

 

Case Study - Meadow Creek:  Solution

1.      Setting up the RIVERMorph database and project file

2.       Define the Impacted Reach Cross-Section Data

3.       Add the Profile data to the Impacted Reach and Reference Reach

4.       Add the Sediment Data to the Impacted Reach and Reference Reach

5.       Classify the Impacted Reach and Reference Reach

6.       Perform the Natural Channel Design Calculations

7.       Layout the Channel in a “Natural” Pattern

 

1.     Setting up the RIVERMorph database and project file

Open RIVERMorph and create a new project.  Right click in the data tree and use the popup menu to create two river nodes (data sets).  The impacted and design data will be stored in the “Meadow Creek” set and the reference reach will be stored in “Wolsey Branch Spring”.  Rename the two nodes as shown.

 

Create three reaches under the “Meadow Creek” river node.  The first reach is called “Impacted” and will store the existing conditions survey and the design calculations for a tributary of Meadow Creek through the wetland mitigation project.  The second reach is “Historical” and stores planform data collected from historical mapping of Meadow Creek for reference.  “Meadow Creek”, the last reach, contains data for the main stem below the project reach.  These reaches are in the Meadow Creek watershed.  Rename the reach nodes as shown.

 

Create one reach in the “Wolsey Branch Spring” data set named “Reference Reach”.  The reference reach is in a separate watershed so it is useful to store it under a separate river node in the database.

 

 

Case Study - Meadow Creek:  Solution

1.       Setting up the RIVERMorph database and project file

2.      Define the Impacted Reach Cross-Section Data

3.       Add the Profile data to the Impacted Reach and Reference Reach

4.       Add the Sediment Data to the Impacted Reach and Reference Reach

5.       Classify the Impacted Reach and Reference Reach

6.       Perform the Natural Channel Design Calculations

7.       Layout the Channel in a “Natural” Pattern

 

 

2.     Define the Impacted Reach Cross-Section Data

The impacted reach data set will include a surveyed riffle cross section; the reference reach data set will include a pool and a riffle.  We will configure the RIVERMorph database to store and analyze this data.

 

Expand the “Impacted” reach and cross section nodes under Meadow Creek in the RIVERMorph data tree.  Right click on the cross section nodes and use the popup menu to add a cross section named “Riffle”.

 

Enter the first table of survey data into this “Riffle” cross-section screen.  Remember to check the “Type” of cross section at the top of the screen, it should be set to Riffle.  Create the Reference Reach cross sections in Wolsey Branch the same way.

 

 

Save your data after entering each cross section.

 

Click the graph tab to view the cross section.  Could you guess where bankfull elevation falls by looking at the graph without the bankfull indicators?  It is very difficult in incised, gully channels.  The bankfull indicators correspond to annual flood predictions and recent floodplain incision and depositional features.  Click the BKF tool button to align the bankfull elevation with the bankfull indicators.  The bankfull elevation should appear in the toolbar as 88.82.  This number is displayed with greater precision than may be necessary and will vary with the same error as the survey data.  Save your data.

 

Click the summary tab to view an analysis of the cross section data.  The screen will display the anticipated stream classification A or G.  The profile in the impacted reach shows that the bankfull hydraulic slope is S_bkf = 0.004.  With this slope, the stream classification will likely be a G stream type.

 

We will use this riffle cross section to estimate the bankfull discharge and other design parameters so take care not to change the surveyed values.  You can copy the data from this screen using the toolbar and paste it into another cross section to make changes to bankfull elevation or other parameters if you want to preserve the original data. 

 

Additional cross sections are supplied to the database and analyzed in the same way.  Typically pools, riffles, runs and glides, if available, are measured in the impacted reach.  You can experiment with the cross section tools by adding other cross sections to this reach node.  Remember to set the type (riffle, pool, etc.) each time you add a cross section.  

 

 

Case Study - Meadow Creek:  Solution

1.       Setting up the RIVERMorph database and project file

2.       Define the Impacted Reach Cross-Section Data

3.       Add the Profile data to the Reference Reach

4.       Add the Sediment Data to the Impacted Reach and Reference Reach

5.       Classify the Impacted Reach and Reference Reach

6.       Perform the Natural Channel Design Calculations

7.       Layout the Channel in a “Natural” Pattern

 

 

3. Add the Profile data to the Reference Reach

 

We will now add the surveyed longitudinal profile data to the Reference Reach to help develop dimensionless ratios needed for natural channel design.  Expand the “Wolsey Branch Springs” River node and the “Reference Reach” Reach node.  Right-click on the “Profiles” node and add a profile.  Before you enter data, be sure the “rod” and “water as depth” state buttons are depressed in the toolbar.  Enter the following survey information in the blank Profile data grid:

 

DIST	CH	WS	BKF
0	9.18	0.2
2	9.52	0.3	8.35
5	9.61	0.23
10	9.65	0.26
14	9.62	0.1
18	9.77	0.1	8
24	9.83	0.2
30	9.96	0.3
36	10.08	0.4
40	10.08	0.4
45	10.06	0.4	8.41
48	9.87	0.2
52	10	0.1
55	10.3	0.4
59	10.38	0.5	9.1
63	10.24	0.3
67	10.31	0.33
72	10.45	0.47
76	10.27	0.3
81	10.24	0.2
87	10.19	0.1	9.29
90	10.22	0.1
93	10.39	0.2
98	10.51	0.3
104	10.69	0.4
108	10.73	0.4
113	10.67	0.3
118	10.62	0.1
123	10.85	0.1
127	11	0.12	9.91
133	11.01	0.1
139	11.04	0.1
143	11.17	0.2
147	11.19	0.2
150	11.3	0.3
153	11.2	0.1
153.3	11.39	0.1
156	11.59	0.2
158	11.68	0.3
160	11.75	0.4
164	11.66	0.3
169	11.66	0.3	10.41
176	11.79	0.28
179	11.61	0.06
183	11.68	0.1
186	11.86	0.1
188	11.96	0.1
192	12.27	0.4
198	12.31	0.4
203	12.34	0.4

                                                                                                                                                           

 

Since the cross sections have already been input, you can place them along the profile by specifying their profile station at the bottom of the data screen.  The riffle cross section is located at profile station 93 and the pool at 160.  Enter this data into the grid.

 

Select the “Turning Points” tab.  Set the bench mark elevation to 880 and the backsite rod reading to 0 in the toolbar.  Now you can return to the “Profile Data” tab and click the “Elev” state button to view your data in real elevations.  Data entry for this profile is now complete. 

 

To measure slopes and depths, proceed to the “Measurements” tab and click the “Graph” button.  This will open a new window with the longitudinal profile graph…which should look like this:

Use the graph measurement tool to populate all of the fields on the “Measurements” tab.  When you have measured all of the facets, you should have results similar to the following:

 

 

Once this grid is complete, save your data.  You are now finished with the profile portion of the reference reach data set.

 

 

 

Case Study - Meadow Creek:  Solution

1.       Setting up the RIVERMorph database and project file

2.       Define the Impacted Reach Cross-Section Data

3.       Add the Profile data to the Reference Reach

4.      Add the Sediment Data to the Impacted Reach and Reference Reach

5.       Classify the Impacted Reach and Reference Reach

6.       Perform the Natural Channel Design Calculations

7.       Layout the Channel in a “Natural” Pattern

 

4.  Add the Sediment Data to the Impacted Reach and Reference Reach

 

 

Create a new pebble count data set in the reference reach named “Reach” for reach-average.  Add the following pebble count data:

 

 

Be sure to set the sample type as “Reach” in the pebble count toolbar.

 

This completes sediment data in the reference reach.  The impacted reach will have three particle data sets: “Reach Average” (pebble count), “Riffle” (pebble count), and “Bar Sample” (sieves).  Create these three data sets with the following data:

 

Particle size data is now complete, RIVERMorph does all of the analysis necessary to derive the sediment sizes used for sediment transport competency analysis later on in the natural channel design module.  Be sure to save your data!

 

 

 

Case Study - Meadow Creek:  Solution

1.       Setting up the RIVERMorph database and project file

2.       Define the Impacted Reach Cross-Section Data

3.       Add the Profile data to the Reference Reach

4.       Add the Sediment Data to the Impacted Reach and Reference Reach

5.      Classify the Impacted Reach and Reference Reach

6.       Perform the Natural Channel Design Calculations

7.       Layout the Channel in a “Natural” Pattern

 

5.  Classify the Impacted Reach and Reference Reach

 

 Let’s start with the Impacted Reach.  Select the “Classification” node in the tree view under the Impacted Reach.  RIVERMorph will display the classification screen.

1.      Select a pebble count from the list at the top of the screen to load the D50.

2.      Enter the Valley Morphology data.

3.      Enter the Location and Date of Survey.

4.      Enter the bankfull data as shown below.  RIVERMorph will classify the data as it is entered and you can always force a calculation by clicking a button on the toolbar.  The impacted reach is a G5c stream type, which means that it has gully characteristics at low slope.  Refer to Rosgen 1996 for a complete description of this stream type.  This stream type is not unexpected for the impacted reach, it is what remains from a straightened or “ditched” channel that is incising and becoming entrenched.  Compare the classification to the valley type you recorded near the top of the screen.

 

 

 

Now for the reference reach.  This time we are going to use the cross section and profile information already entered (refer to part 3 of this example) to help populate most of the fields in the classification screen.  We do this by activating the “Ratios” node, which is a “child” of the “Classification” node.  Expand the tree view in the reference reach, expand the classification node and click “Ratios”.  You will see a screen similar to the one shown below. 

 

The “Ratios” screen is used to record/view dimensionless ratios that are properties of the active reach.  RIVERMorph will load all of your cross sections and profiles with the same reach identification.

 

On the “Dimension” tab, select the riffle cross section by checking the box next to its name.  Some data will be extracted from the cross section and placed into the blank fields on this screen as shown below.  Next select the pool cross section to see which values are updated.

 

Select the “Pattern” tab and enter the values shown below.  If you had used RIVERMorph’s GIS to measure this data it would appear automatically.

 

 

Next select the “Profile” tab and then select a profile data set from the Profile List.  All of the saved values will populate the blank cells.  Click the “Update Dimensions Tab” button to copy the max. depth values to the “Dimensions” tab, if you prefer.

 

 

The last page of the “Ratios” screen is for saving hydraulics information.  Complete the information as shown below.

 

 

Save your data.  Close this window and refresh the classification screen.  RIVERMorph will populate the classification screen with the average values you saved in the dimensionless ratios table.

 

 

Once the remainder of your data has been entered you should have a classification screen that looks similar to the one shown above.  Important – check the Reference Reach box at the bottom of the screen.  Be sure to save your data.

 

This example has illustrated some techniques for measuring and classifying your streams.  This impacted reach is a G stream type, which is a very unstable gully.  The reference reach is a stable E stream type with low width to depth ratio and some bedrock control.  Next time we’ll use this information to help design improvements for the impacted reach.

 

 

Case Study - Meadow Creek:  Solution

1.       Setting up the RIVERMorph database and project file

2.       Define the Impacted Reach Cross-Section Data

3.       Add the Profile data to the Reference Reach

4.       Add the Sediment Data to the Impacted Reach and Reference Reach

5.       Classify the Impacted Reach and Reference Reach

6.      Perform the Natural Channel Design Calculations

7.       Layout the Channel in a “Natural” Pattern

 

6. Perform the Natural Channel Design Calculations

 

This part of the example will illustrate the input and output of a natural channel design using the reference reach approach and sediment transport validation.

 

Expand the Impacted Reach, Designs node and click NCD in the tree view.  RIVERMorph will display the first screen, shown below, of a step-by-step process that will walk you through the design sequence.

 

 

The list on this tab will contain all of the reference reaches available in the database.  This database only contains the one we entered in the last part of this example.  Select Wolsey Branch Springs from the list (or whatever you named your reference reach).  The description will display some of the key parameters of this reach.  Reach condition and biological assessment refer to Pfankuch and SVAP results (see Help).

 

After selecting a reference reach, proceed to the second tab to enter the Boundary Conditions. 

 

 

The Boundary Conditions screen contains all of the additional input parameters.  Change the valley slope to 0.002.  This means that earthwork will have to be performed to change elevations in the floodplain.  Change the Dmax Bar to 12.  Field reviews have indicated that the original bar sample contained large particles being deposited by local bank erosion in the gully.  A more precise estimate of the largest portion of the bedload (characterized by deposits) is 12 mm.  Select the options shown above and click the Go Design! button.

 

 

 

 

The initial solution is shown on the Results tab.  If you are using sediment transport competency validation, then tweak the design until you get a Green light in the Sediment Transport Competency portion of the screen (shown above).  Select a channel pattern that will match the riffle geometry and the depth required to transport the sediment.  This design is valid for one meander wavelength of the new channel.  You can link meanders together to form chains, or vary the design from one to the other by selecting different input parameters or by varying the solution.

 

Save your design.  View the suggested meander pattern and longitudinal profile on the Plan View and Long Pro tabs.  Click the Typical Sections tab to create riffle, pool and other cross sections.

 

 

The “rubber-band” cross section can be edited to produce a variety of shapes that have the required bankfull parameters.   Use the reference reach cross sections as templates (see Help\Cross Sections\Overlays).  You can create a cross section node out of one of these templates by clicking the “XS Exp” button.

 

Next, use the RIVERMorph output to layout your design on paper.  Generate a report of your meander wavelength calculations, which can be sent to your CADD department for assistance in laying out the channel plan form geometry.  Similarly, generate reports for your NCD profile and cross sectional analyses.  If at any time you need to rework your plan form, profile of cross sectional geometry during final plan preparation, you can quickly check the impact of these changes on your design using RIVERMorph.

 

RIVERMORPH Example 113:  Solution

1.        Setting up the RIVERMorph database

2.        Add the Cross Section data to the Impacted Reach and Reference Reach

3.        Add the Profile data to the Reference Reach

4.        Add the Sediment Data to the Impacted Reach and Reference Reach

5.        Classify the Impacted Reach and Reference Reach

6.        Perform the Natural Channel Design Calculations

7.        Layout the Channel in a “Natural” Pattern

 

7. Layout the Channel in a “Natural” Pattern