20180179 Ver 1_DWR comments Draft Mitigation Plan_20190619

DWR comments on the Grassy Creek Draft Mitigation Plan
June 19, 2019
1. Section 3.6.2- Existing Reach Descriptions- during the site visit DWR thought there were some
wetlands adjacent to R3 and in addition, the possibility of some restoration or enhancement due
to the raising the channel bed. There was no mention of any wetlands in the reach description
for R3 (the wetlands were mentioned in Section 3.7), however, some are present in the PJD and
in the initial proposal some wetland re-establishment was proposed.
2. Section 3.6.2- Reach 5- this section discusses a gravel laver approximately 3 feet down as
evidence of its incision. However, in the design sheet for this reach (17) it appears that the
channel bed is only being raised a foot or so on average. This brings into question the functional
uplift for this reach and the ratio proposed.
3. Section 6.2.3- Planting Materials and Methods- this section states that the trees must be
installed by the end of May to meet the requirements for the first year of monitoring. If tree
species are planted past March, DWR and the IRT will review closely the survivability of those
species and if survivability is reduced or low, it is likely the IRT will require an additional year of
vegetative monitoring. DWR recommends planting by the end of March.
4. Section 8 —Performance Standards- please specify the flow standard for intermittent (only)
streams is 30 days of continuous flow.
5. Design sheet 3- DWR would prefer to see the typical cross sections with side slopes with a
specific slope labeled, such as 3:1 for riffles or 2:1 for side of a pool.
6. Design sheet 14 or 15- please include the jurisdictional wetlands on the design sheets so we can
see if any channel will be constructed through wetlands.
7. Design sheets 17 and 18- as stated above- and from recalling discussions on site and verbiage in
Section 6.2.1, DWR was under the impression that the severely incised reaches, R5, R6, R6a and
R7 would have the channel beds raised significantly. However, except for a portion of R6a and
R6 most of the reaches are raised only a foot or so. Given this fact, DWR is calling into question
the restoration ratio being utilized for these reaches.
8. DWR requires the installation of a stream gauge for R6 at station 11+30.
9. Why did WLS not run the Stream Quantification Tool for R4?
10. As documented in the meeting minutes from the January 9, 2018 site visit, DWR recommended
a ratio of 8:1 for R4. The current ratio for this reach is listed as 5:1. While there are four planned
meander bend activities, the cattle usage of this reach was limited if at all. DWR recommends
the proper ratio for this reach to be closer to 7.5:1 than 5:1.
11. What is the status of the proposed project for stream restoration work in the State Park
between Reach 1 and Reach 2? If this project is not done, DWR would like to know the
approach WLS will take to keep both adjacent reaches from destabilizing.