Wis. Admin. Code Department of Natural Resources NR 328.38

Current through October 28, 2024

Section NR 328.38 - Data requirements and site assessment methods

Applicants and department staff shall adhere to the following data requirements and site assessment methods:

(1) IDENTIFICATION OF ECOREGIONS AND URBAN AREAS. Ecoregions and urban areas identified in Figure 1 are based on scientific literature characterizing the ecology of Wisconsin streams (Lyons et al. 1996; Wang et al.1997; Lyons et al. 2001; Wang et al. 2003; and Weigel et al. 2006), Omernik 1987, and Omernik et al. 2000. The department shall provide applicants with maps and internet-based location tools for the purpose of determining ecoregion and urban watersheds.

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Note: Lyons, J., L. Wang, and T. Simonson. 1996. Development and Validation of an index of biotic integrity for coldwater streams in Wisconsin. North American Journal of Fisheries Management 16: 241-265.

Lyons, J., R.R. Piette, and K.W. Niermeyer. 2001. Development, validation, and application of a fish-based index of biotic integrity for Wisconsin's large warmwater rivers. Transactions of the American Fisheries Society 130:1077-1094.

Omernik, J.M., 1987, Ecoregions of the conterminous United States (map supplement): Annals of the Association of American Geographers, v. 77, no. 1, p.

Omernik, J. M., Chapman, S. S., Lillie, R. A., Dumke, R. T. (2000) "Ecoregions of Wisconsin" Transactions of the Wisconsin Academy of Sciences, Arts, and Letters 88: 77-103

Wang, L., J. Lyons, P. Kanehl, and R. Gatti. 1997. Influences of watershed land use on habitat quality and biotic integrity in Wisconsin streams. Fisheries 22(6):6-12.

Wang, L., J. Lyons, P. Rasmussen, P. Seelbach, T. Simon, M. Wiley, P. Kanehl, E. Baker, S. Niemela, and P.M. Stewart. 2003. Watershed, reach, and riparian influences on stream fish assemblages in the Northern Lakes and Forest Ecoregion, U.S.A. Canadian Journal of Fisheries and Aquatic Sciences 60: 491-505.

Weigel, B.M, J. Lyons, and P. Rasmussen. 2006. Relative influence of environmental variables at multiple spatial scales on fishes in Wisconsin's warmwater nonwadeable rivers. American Fisheries Society Symposium 48:493-511.

(2) CALCULATION OF STREAM BANK EROSION INTENSITY INDEX. The department shall provide applicants with worksheets and internet-based computer software for the purpose of calculating the bank erosion potential index (BEPI). When the department or applicants assess erosion at the bank stabilization site, they shall apply methods outlined in Table 1 to calculate a bank erosion potential index (BEPI) score. For each continuous treatment site of 300 feet or less, applicants shall submit at least one BEPI assessment. For continuous treatments greater than 300 feet, applicants shall conduct and submit BEPI assessments at 150 foot intervals along the treatment site.

Table 1

Bank Erosion Potential Index (Bepi) Score Worksheet

Applicants and department staff shall use this worksheet to calculate erosion intensity pursuant to s. NR 328.38(2).

STREAMBANK VARIABLES

DESCRIPTIVE CATEGORIES

Erosion Intensity Value is Located in Parenthesis at Bottom of Each Category Box.

SCORE

Bank Materials -

predominance of bank materials at toe (between bed and ¹OHWM on bank face).

Bedrock Outcrop

Stop assessment BEPI=0

Cobble >3 inches

(-10 points)

Silt/Clay

(0 points)

Gravel <3 inches

(5 points)

Sandy Gravel

(7 points)

Non plastic sands and silts (10 points)

Hydraulic Influence of Upstream Structures - distance (number of channel widths) to bridges, culverts, or dams. Calculation:

Number of Channel Widths= Stream Distance to Structure / Average Channel Width

10+ channel widths

(1 point)

5.1-10

channel widths (2 points)

2.1-5

channel widths

(3 points)

0-2

channel widths

(4 points)

²Max Bank Height (feet) Divided by the OHWM Height (feet)

Calculation:

Max Bank Height /

OHWM Height

1 - 1.19

Very Low or Low

(2 points)

1.2 - 1.5

Medium

(5 points)

1.6 - 2.0

High

(7 points)

2.1 - 2.8

Very High

(8 points)

>2.8

Extreme (10 points)

³Bank Slope(degrees) - measure rise/run and translate into angle degree Calculation: Bank Slope= Inverse Tangent (Rise/ Run)

0 - 20

Very Low

(1 point)

21 - 60

Low

(3 points)

61 - 80

Moderate

(5 points)

81 - 90

Vertical

(7 points)

91+

Undercut

(10 points)

⁴Stratification/ Bank Layering-type of soil layering occurring on the bank face.

No stratification (0 points)

No stratification, seepage present

(3 points)

Stratified above OHWM

(4 points)

Stratified above OHWM with seepage present, or stratified below OHWM

(7 points)

Stratified below OHWM with visual seepage

(10 points)

⁵Bank Vegetation -

abundance of the vegetation, roots, and tree-falls occurring between the OHWM and the bank lip.

Rock outcrop bank-unable to support vegetation.

(-7 points)

Dense vegetation <30% bare soil visible (-4 points)

Clumps of vegetation 30-59% bare soil visible

(0 points)

Sparse vegetation 60-90% bare soil visible

(4 points)

Vegetation absent >90% bare soil visible

(7 points)

⁶Thalweg Location - deepest part of the channel and the location of stream current.

Located across the stream, against opposite bank (0 points)

Flowing down the center of the stream channel

(2 points)

Immediately adjacent to bank proposed for erosion control (8 points)

Bank Erosion Potential Index (BEPI) Score

Note: Table 1 is adapted from Rosgen, David L. "A Practical Method of Computing Streambank Erosion Rate", Wildland Hydrology Inc., Pagosa Springs, CO, 10 pp.

1. Ordinary High Water Mark (OHWM) means the point on the bank or shore up to which the presence and action of water is so continuous as to leave a distinct mark either by erosion, destruction of terrestrial vegetation or other easily recognizable characteristics. If bank material is composed of bedrock outcrop, stop with the BEPI assessment at this point; the reported total BEPI score is assumed equal to 0.

2. Maximum bank height means the vertical measure (feet) from the bank toe to the top of the bank lip, irrespective of changes in the water level. Bank toe is the inflection or bending point between the bank face and stream bed.

3. To measure the bank slope (degrees), the rise and run must be measured from the bank toe to the top of the bank lip. With your measure tape or stick, place the end firmly on the bank toe, parallel to the bank face and measure up to the bank lip to find the rise or max bank height. Subsequently, measure the run from the bank toe to the bank lip. From these measures, one should be able to calculate the bank slope with the formula `bank slope= inverse tangent (rise/run)'. Additionally, the BEPI Calculator is available on the Department's website http://dnr.wi.gov. This website automatically calculates the bank slope and BEPI score after inputting fields for bank materials, structures upstream, OHWM height, max bank height, distance to bank face, bank layering/stratification, bank vegetation, and thalweg location.

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4. Stratification or bank layering means soils consisting of alternating layers of varying soils or textures.

5. Bank vegetation is the type and abundance of vegetation occurring between the ordinary high water mark (OHWM) and the bank lip. To assess the abundance of vegetation on the targeted bank, apply a 10 foot wide window of assessment from the OHWM to the top of the bank. The following percentages are assigned for the categories: bare soil visible over less than 30% of the surface area=dense vegetation; bare soil visible across 30-59% of the surface area= clumps of vegetation; bare soil visible across 60-90% of the surface area = vegetation sparse; bare soil visible across > 90% of the surface area = vegetation absent. Root wads, tree falls, and snags on the bank are considered in this assessment, because of their influence on thalweg, sediment transport, scour, and bank protection. After assessing the percentage of bare soil in the `box', record its associated point value.

6. Thalweg means the deepest part of the channel or the location of fastest current. To find the thalweg, the channel must be divided into thirds. The applicant needs to perform one or a mixture of tests for the three segments in determining its location. The following tests are suggested: float an object such as an orange peel down the stream to find the segment of fastest current, find the segment with the bubble line visible at the water's surface, or find the deepest part of the channel, if safe. After locating the thalweg, record its proximity to the tested bank, adjacent (closest), center, or opposite (furthest) and record its associated point value.

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(3) BANK EDGE RECESSION MEASUREMENTS. Methods of measuring bank edge recession shall include all of the following: establishment of a physical measurement reference line between at least 2 headstakes; date-imbedded photographs showing the initial installation of the reference line and headstakes; reference distance measures to the bank lip shall be reported on department supplied forms; and time between separate measurements shall equal or exceed 3 months during the open-water season.

Wis. Admin. Code Department of Natural Resources NR 328.38

CR 06-126: cr. Register July 2007 No. 619, eff. 8-1-07.