OR-CONS-393: FILTER STRIP DESIGN AID

For

SEDIMENT, PARTICULATE ORGANICS & SEDIMENT

ABSORBED CONTAMINANT REDUCTION

**Client:** **Date:**

**Farm Number: Tract(s): Field(s):**

**Contract Item Number:** **Filter Number\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

##### DATA FOR DESIGN

**Design Storm Information:**

**10-yr. frequency storm EI value =** \_\_\_\_\_\_\_\_, Oregon State
RUSLE 10-yr. EI Map, FOTG, Section I. Erosion Prediction, P Factor.

# RUSLE FACTORS SPECIFIC TO FILTER STRIP DESIGN:

**RUSLE R Factor \_\_\_\_\_\_\_\_\_, or RUSLE Req Factor
\_\_\_\_\_\_\_\_\_,** **Soil Kf \_\_\_\_\_\_\_\_\_, Soil T
\_\_\_\_\_\_\_\_**

# 

# RUSLE L (slope length) \_\_\_\_\_\_ft., RUSLE S (percent slope) \_\_\_\_\_%. Overall LS \_\_\_\_\_\_\_\_\_\_

# 

# Note: RUSLE L & S include the slope % and slope length in feet that transect the planned filter strip. L & S end at the lower edge of the filter strip. For complex slopes with multiple slope breaks RUSLE S is the "Equivalent S." [RUSLE S is also the Maximum % Hillslope Gradient for the Filter Strip noted in Table 1 in the 393 Standard]{.underline}. For more information see FOTG, Section I. Erosion Prediction, LS Factors.

**RUSLE C FACTOR \_\_\_\_\_\_\_\_\_\_, RUSLE P FACTOR
\_\_\_\_\_\_\_\_\_.**

**NOTE:** The C (Cover Management) Factor and P (Support Practice)
Factor is for the L on cropland, introduced pasture/hayland, disturbed
forestland or other disturbed land. For more information see FOTG,
Section I. Erosion Prediction, C Factor and P Factor.

**RUSLE A \_\_\_\_\_\_\_\_\_\_ tons/acre/year, above filter strip (A =
R/Req x Kf x LS x C x P)**

**FILTER STRIP DESIGN REQUIREMENTS:**

1.  **MINIMUM WIDTH (Flow Length) = RUSLE L \_\_\_\_\_\_\_ft. 10:1 =
    \_\_\_\_\_\_\_\_\_\_ ft.**

2.  **MAXIMUM CONTOUR VARIATION (MCV):**

> **MCV = Max. % Hill Slope (RUSLE S) \_\_\_\_\_\_\_\_ x Contour
> Variation \_\_\_\_\_\_ = \_\_\_\_\_\_\_\_**
>
> **Gradient Factor**
>
> **MCV = \_\_\_\_\_\_\_\_\_\_% (MCV shall not \> 5%)**
>
> **Note:** Refer to Table 1. In the Filter Strip Standard, NRCS,
> Oregon, December 2001 for Contour Variation Factors to determine MCV.

3.  **ADDITIONAL FILTER STRIP WIDTH FOR OTHER PURPOSES SELECTED BY THE
    OPERATOR**

> **Indicate Purpose(s):**

-   **Reduce Dissolved Contaminants in Runoff\_\_\_\_\_\_\_ ft.**

-   **Zone 3 for Riparian Forest Buffer, Practice Standard
    391\_\_\_\_\_\_\_ ft.**

-   **Habitat for Wildlife & Beneficial Insects \_\_\_\_\_\_\_ft.**

> **Additional Width \_\_\_\_\_\_\_\_\_\_ ft.**
>
> **Total Filter = Min. Width \_\_\_\_\_\_\_\_ ft. + Add. Width
> \_\_\_\_\_\_ ft. = \_\_\_\_\_\_\_\_\_\_ ft.**
>
> **Strip Width** (Due to topography on site the filter strip width may
> vary.)

4.  **Filter Strip Area Ac. = Total Filter \_\_\_\_\_\_ft. X Filter
    \_\_\_\_\_\_ft./43,456sq.ft. \_\_\_\_\_\_\_Acres.**

> **Width Length**

5.  **OTHER DOCUMENTATION:**

-   **RUSLE Factors, Summaries, Etc.**

-   **Filter Strip 393 Job Sheet and Specification Worksheet.**

-   **Other.**

6.  **ADDITIONAL DESIGN REQUIREMENTS/COMMENTS:**

# Filter Strip Job Class:

######  Job Class I II III IV V

> **Control: Area in Acres (Circle One) 1 4 8 \>8 \>8**

Planner Date

393 Job Approval Authority -- I & E \_\_\_\_\_Design
\_\_\_\_\_Construction \_\_\_\_\_\_.

Reviewer\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Date\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

393 Job Approval Authority -- I & E \_\_\_\_\_Design
\_\_\_\_\_Construction \_\_\_\_\_\_.