Impacts of beaver dams on hydrologic and temperature regimes in a mountain stream

Majerova, M.; Neilson, B. T.; Schmadel, N. M.; Wheaton, J. M.; Snow, C. J.

doi:https://doi.org/10.5194/hess-19-3541-2015

Articles | Volume 19, issue 8

https://doi.org/10.5194/hess-19-3541-2015

© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

https://doi.org/10.5194/hess-19-3541-2015

© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

Articles | Volume 19, issue 8

Research article

|

11 Aug 2015

Research article |

| 11 Aug 2015

Impacts of beaver dams on hydrologic and temperature regimes in a mountain stream

M. Majerova, B. T. Neilson, N. M. Schmadel, J. M. Wheaton, and C. J. Snow

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Final revised paper (published on 11 Aug 2015)
Supplement to the final revised paper
Preprint (discussion started on 22 Jan 2015)
Supplement to the preprint

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

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- Supplement

RC C322: 'technical review: Impacts of beaver dams on hydrologic and temperature regimes in a mountain stream', Anonymous Referee #1, 26 Feb 2015
- AC C1115: 'Reply to reviewer 1', Milada Majerova, 18 Apr 2015
SC C447: 'Reviewer #2 comments to Majerova et al manuscript', Megan Klaar, 06 Mar 2015
- AC C1143: 'Reply to reviewer 2', Milada Majerova, 18 Apr 2015
RC C468: 'Review: Majerova et al', Megan Klaar, 06 Mar 2015

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

ED: Reconsider after major revisions (22 Apr 2015) by Florian Pappenberger

AR by Milada Majerova on behalf of the Authors (08 May 2015) Author's response Manuscript

ED: Referee Nomination & Report Request started (20 May 2015) by Florian Pappenberger

RR by Anonymous Referee #1 (17 Jun 2015)

Suggestions for revision or reasons for rejection

I have reviewed the revised version of the manuscript draft: “Impacts of beaver dams on hydrologic and temperature regimes in a mountain stream” by Majerova et al. The authors build a strong case for the need for more data-driven studies regarding the effects of beaver impoundment on stream hydraulics and habitat, as many previous studies are somewhat speculative in nature. The revised paper well-reflects the suggestions of the two previous reviews. I particularly appreciate the attention to detail with the responses to each point, and the overall high-quality of writing of the main text. The new air temperature data is useful to the effort to separate beaver impacts from inter-annual climate variability. The ANOVA test may not be the most appropriate to identify the potential effects of warmer air temperatures in 2010 on water temperature, but it does help, and the normalized delta T temps are useful. The only addition I take some issue with is the statement L411: “While the discharge in 2010 could have been influenced by irrigation practices in the nearby field, irrigation usually occurs only from mid-May to mid- or late-July and therefore, only had a potential impact during this time.” It could be expected that several months of irrigation would increase local groundwater levels, and this increase in storage could affect groundwater discharge to the stream for some remainder of the season. This is similar to the author’s hypothesis that greater spring overbank flows and floodplain storage events after dam building augments the local groundwater, and effects groundwater to the discharge over the summer. Perhaps rethink your strong wording on L411 and elsewhere (note all my line numbers refer to the “tracked changes” version of the revised manuscript).
Overall I find this paper in great shape and recommend publication, possible after some minor revisions.
Some minor points to consider:
L15 There are other mechanisms by which beaver dams potentially impact these characteristics in addition to flooding and GW/SW exchange
L23 and in body text: One study’s reach scale is another’s sub-reach scale, so best to define some general range here so the reader knows what your reference scale for these terms is
L49: Typically solar radiation heats the bed, which in turn transfers heat to the water column via conduction. Therefore residence time, bed color, and depth are also important parameters in addition to increased surface water area
L64: what was expected and why was this expectation exceeded?
L70 replace “a day” with “1 day”
L70 downstream delivery of water?
L77-81 great to point out these contradictions, make sure to address the best you can with your data in the discussion
L90 is this Beaver Management Plan citation in the correct format?
L100 consider removing this sentence, it belongs in the discussion/conclusions
L113 Beavers are only recently (~ last 20 yr) returning to many systems after strong hunting pressures. How old are these relic structures?
L124 remove “roughly”
L152 quantify reach scale ranges
L168 move the sentence “The flow velocity…” above the previous sentence
L172 comma after “activity”
Equation 1 define the variables Qd, Cd
L221 consider including some details on the UAS thermal camera system used here, or provide a link to the aggie air website. This will be one of the first published examples of UAS TIR data for stream habitat/refugia so there will be much interest in the equipment used
L 414 citing the specific personal communication here as you did in the reviewer response will give your irrigation timing statement more weight
L516 Perhaps plug the use of FO-DTS and TIR for capturing thermal patchiness at nested scales

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ED: Publish subject to minor revisions (Editor review) (22 Jun 2015) by Florian Pappenberger

AR by Milada Majerova on behalf of the Authors (30 Jun 2015) Author's response Manuscript

ED: Publish as is (02 Jul 2015) by Florian Pappenberger

AR by Milada Majerova on behalf of the Authors (12 Jul 2015)

Short summary

This study quantifies the impacts of beaver on hydrologic and temperature regimes, as well as highlights the importance of understanding the spatial and temporal scales of those impacts. Reach-scale discharge showed shift from losing to gaining. Temperature increased by 0.38°C (3.8%) and mean residence time by 230%. At the sub-reach scale, discharge gains and losses increased in variability. At the beaver dam scale, we observed increase in thermal heterogeneity with warmer and cooler niches.