east san joaquin water quality coalition...the coalition will mail postcards to members identified...

East San Joaquin Water Quality Coalition Sediment Discharge and Erosion Assessment Report Proximity to Secondary Tributaries June 24, 2016

Introduction The East San Joaquin Water Quality Coalition (ESJWQC or Coalition) received a conditional approval of the Sediment Discharge and Erosion Assessment Report (SDEAR) on July 24, 2015. In response to that conditional approval, on December 1, 2015 the Coalition submitted to the Central Valley Regional Water Quality Control Board (Regional Water Board) a work plan with a timeline to address proximity to surface waters on December 1, 2015. This Work Plan was conditionally approved on December 24, 2015.

The goal of the Work Plan is to identify parcels that are required to complete the Sediment and Erosion Control Plan (SECP) based on their proximity to surface water. In the Work Plan, the Coalition agreed to evaluate the adjacent member parcels using a phased approach based on the size and flow of waterbodies in the Coalition region. This assessment is one of three reports promised in the Work Plan: 1) analysis of parcels within proximity to major waterbodies, 2) analysis of parcels within proximity to secondary tributaries and 3) analysis of all remaining waterbodies.

Despite their proximity, many of these parcels are not able to discharge sediment due to several factors including; levees between the parcel and the waterbody, the parcel is below the elevation of the waterbody, and/or the presence of a buffer of natural riparian vegetation between the farmed land and the waterbody. Consequently, parcels identified as being adjacent to a waterbody but meeting one of the following criteria will not require an SECP:

1. The parcel is below the level of the adjacent surface water body or a hydraulic barrier (berm, levee, or elevated roadway) is between the surface water and the parcel.

2. The parcel has riparian vegetation that would prevent sediment discharges or erosion.

The Coalition submitted the SDEAR Proximity to Major Waterbodies analysis on March 24, 2016, identifying member parcels along large waterbodies that will need to complete an SECP by February 2017. For members with parcels that were not already notified as requiring an SECP, the Coalition will inquire whether there is a hydraulic barrier or riparian vegetation that prohibits sediment discharges or erosion.

This report includes an assessment of member parcels that are within proximity of secondary tributaries and utilizes the same methodology explained in the major waterbodies assessment. In addition, the Coalition evaluated whether there is a hydraulic barrier based on levee information from the Department of Water Resources (DWR). Member parcels within proximity to secondary tributaries,

ESJWQC SDEAR – Proximity to Secondary Tributaries June 24, 2016 1

excluding those with hydrological barriers or riparian vegetation, will need to have a completed SECP by February 2018.

On December 24, 2017, the Coalition will identify adjacent member parcels along remaining waterbodies (e.g. drains, ephemeral waterbodies, conveyance structures/laterals) that would need to complete an SECP by February 2019.

Levees within the Coalition Region There are both federal and non-federal levees within the ESJWQC region. Federal levees include levees built by the United States Army Corps of Engineers (USACE) and maintained by the USACE or locally maintained. These levees are defined by the State Plan of Flood Control under the California Public Resources Code Section 5096.805. Non-Federal levees have not been constructed by USACE and are not part of the State Plan of Flood Control. These levees are any man-made facilities that alter the direction of the natural flow path. Both types of levees have been mapped by the DWR during the development of Best Available Maps to display 100- and 200-year floodplain for areas within the Sacramento-San Joaquin Valley watershed (Figure 1). Parcels adjacent to a levee do not need to complete an SECP.

Update to the Proximity to Major Waterbodies In addition to evaluating secondary tributaries with levees, the Coalition has revisited the major waterbodies to determine if member parcels have mapped levees on their property. The SDEAR Proximity to Major Waterbodies maps did not include the levee layers and therefore this report includes an update to these maps (Appendix I). Of the member parcels that are enrolled in the ESJWQC and are adjacent to a major waterbody, 21 members (36 parcels) who were required to complete an SECP based on the proximity analysis, will not need an SECP based on the updated levee information.

Addressing the Proximity to Secondary Tributaries The Coalition determined which parcels are enrolled in the ESJWQC and are adjacent to a secondary tributary (within 200 yards). Table 1 includes a list of the secondary tributaries included in this analysis which does not include irrigation canals or ditches (these will be included in the third proximity report). Figure 2 includes a map of the ESJWQC area, member parcels with levees, and the proximity analysis, including an assessment of which areas are within proximity of the tributaries and not enrolled in the Coalition compared to member parcels already mailed SECPs. Figures 3-5 include zoomed in areas of the parcels in proximity of the tributaries and if the member parcels are adjacent to a levee.


Table 1. List of secondary tributaries, alphabetically. Secondary Tributaries Ash Slough Bear Creek Berenda Creek Berenda Slough Black Rascal Creek Canal Creek Cottonwood Creek Deadman Creek Dry Creek, Madera Dry Creek, Merced Dry Creek, Stanislaus Duck Slough Dutchman Creek Lone Willow Slough Mariposa Creek Miles Creek Mustang Creek North Slough Owens Creek Peaslee Creek Turner Slough

Since December 2015, the Coalition has mailed SECPs to 1,209 members with parcels that have the potential to discharge sediment based on 1) the results of the Revised Universal Soil Loss Equation (potential to discharge sediment at greater than 5 tons/acre/year during rainfall runoff events) analysis performed by the Coalition, 2) self-identified through Farm Evaluations, and 3) failure to complete a Farm Evaluation.

There are 518 parcels that may require an SECP based on proximity that have not been previously identified (excludes parcels with mapped levees). The Coalition evaluated the Farm Evaluation responses associated with these parcels and found that 256 parcels have at least one of the following sediment and erosion control measures in place resulting in no discharge of sediment:

1. Berms are constructed at low ends of fields to capture runoff and trap sediment. 2. No storm drainage due to field or soil conditions. 3. Field is lower than surrounding terrain.

The Coalition will mail postcards to members identified in the proximity analysis who are implementing at least one of the above sediment and erosion control measures. The member will be asked to confirm that their parcel is below the level of the adjacent surface water body, or that a hydraulic barrier (berm, levee, or elevated roadway) is located between the surface water and the parcel. If the member indicates that one or more of the conditions apply and provides some documentation, they will not


need to complete an SECP. If they do not indicate that the conditions apply, they will be mailed an SECP which will need to be completed by February 2018.

For the remaining parcels, the Coalition will mail postcards to members inquiring if riparian vegetation prohibits sediment discharges or erosion. Riparian vegetation will be defined as woody vegetation including cottonwood trees, elderberries, eucalyptus, oaks, willows, and woody vines. The riparian vegetation will need to be at least 35 feet wide1 and be present throughout the year. If the member indicates that there is riparian vegetation between their parcel and the river, they will not need to fill out an SECP; if they do not indicate that this is true, an SECP will be mailed to them and will need to be completed by February 2018.

1 NRCS Conservation Practice Standard Code 319 references a minimum of 35 feet to be measured horizontally on a line perpendicular to the watercourse or water body (https://extension.umd.edu/sites/default/files/_docs/programs/riparianbuffers/http___efotg.sc_.egov_.usda_.gov__references_public_MN_391mn.pdf). USDA Forest Service also references 25-30 feet of buffer for sediment settling (http://nac.unl.edu/documents/agroforestrynotes/an04rfb03.pdf).


Figure 1. Federal and Non-Federal Levees within the ESJWQC.


Figure 2. Map of parcels within proximity to secondary tributaries. Parcels identified as Proximity Analysis are enrolled in the ESJWQC but have not been previously identified as requiring an SECP and are not adjacent to a mapped levee. Zoomed in portions of the map are included in Figures 3-5.


Figure 3. STANISLAUS County – Map of parcels within proximity to secondary tributaries. Parcels identified as Proximity Analysis are enrolled in the ESJWQC but have not been previously identified as requiring an SECP and are not adjacent to a mapped levee.


Figure 4. MERCED County - Map of parcels within proximity to secondary tributaries. Parcels identified as Proximity Analysis are enrolled in the ESJWQC but have not been previously identified as requiring an SECP and are not adjacent to a mapped levee.


Figure 5. MADERA County - Map of parcels within proximity to secondary tributaries. Parcels identified as Proximity Analysis are enrolled in the ESJWQC but have not been previously identified as requiring an SECP and are not adjacent to a mapped levee.


Appendix I SDEAR Proximity to Major Waterbodies Amended Maps

The following amended maps include the mapped federal and non-federal levees.

ESJWQC SDEAR –Proximity to Major Waterbodies Amended Maps June 24, 2016 Appendix I - 1

Figure 1. Federal and Non-Federal Levees within the ESJWQC.


Figure 2. Map of parcels within proximity to major waterbodies. Parcels identified as ‘Member Parcels-Levees’ are adjacent to a major waterbody; however the parcel has a levee. Zoomed in portions of the map are included in Figures 3-10.


Figure 3. STANISLAUS RIVER - Map of parcels within proximity to major waterbodies. Parcels identified as Proximity Analysis are enrolled in the ESJWQC but have not been previously identified as requiring an SECP and are not adjacent to a mapped levee.


Figure 4. TUOLUMNE RIVER - Map of parcels within proximity to major waterbodies. Parcels identified as Proximity Analysis are enrolled in the ESJWQC but have not been previously identified as requiring an SECP and are not adjacent to a mapped levee.


Figure 5. MERCED RIVER - Map of parcels within proximity to major waterbodies. Parcels identified as Proximity Analysis are enrolled in the ESJWQC but have not been previously identified as requiring an SECP and are not adjacent to a mapped levee.


Figure 6. SAN JOAQUIN RIVER NEAR MERCED- Map of parcels within proximity to major waterbodies. Parcels identified as Proximity Analysis are enrolled in the ESJWQC but have not been previously identified as requiring an SECP and are not adjacent to a mapped levee.


Figure 7. CHOWCHILLA RIVER - Map of parcels within proximity to major waterbodies. Parcels identified as Proximity Analysis are enrolled in the ESJWQC but have not been previously identified as requiring an SECP and are not adjacent to a mapped levee.


Figure 8. FRESNO RIVER – Map of parcels within proximity to major waterbodies. Parcels identified as Proximity Analysis are enrolled in the ESJWQC but have not been previously identified as requiring an SECP and are not adjacent to a mapped levee.


Figure 9. SAN JOAQUIN RIVER NEAR Madera (south)- Map of parcels within proximity to major waterbodies. Parcels identified as Proximity Analysis are enrolled in the ESJWQC but have not been previously identified as requiring an SECP and are not adjacent to a mapped levee.


Figure 10. SAN JOAQUIN RIVER NEAR Madera (west)- Map of parcels within proximity to major waterbodies. Parcels identified as Proximity Analysis are enrolled in the ESJWQC but have not been previously identified as requiring an SECP and are not adjacent to a mapped levee.


Figure 11. SAN JOAQUIN RIVER NEAR the Stanislaus River- Map of parcels within proximity to major waterbodies. Parcels identified as Proximity Analysis are enrolled in the ESJWQC but have not been previously identified as requiring an SECP and are not adjacent to a mapped levee.


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