Install artificial dams in streams to raise water levels

How is the evidence assessed?
  • Effectiveness
    not assessed
  • Certainty
    not assessed
  • Harms
    not assessed

Study locations

Key messages

  • One study evaluated the effects on butterflies and moths of installing artificial dams in streams to raise water levels. This study was in the USA.




  • Survival (1 study): One replicated, randomized, paired, controlled study in the USA found that installing artificial dams in streams did not increase the survival of Appalachian brown butterfly eggs, caterpillars or pupae.



About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A replicated, randomized, paired, controlled study in 2011–2012 in a pine forest in North Carolina, USA (Aschehoug et al. 2015) found that installing artificial dams in headwater streams to raise water levels did not increase the survival of Appalachian brown Satyrodes appalachia eggs, caterpillars or pupae. In plots where dams were installed, the survival of Appalachian brown eggs (23–43%) and caterpillars and pupae (37%) was not significantly different from plots where dams were not installed (eggs: 56–74%; caterpillars and pupae: 20%). In plots where artificial dams were installed and trees were removed, both egg (33–42%) and caterpillar and pupal (14%) survival were also similar to plots where dams were not installed and trees remained (egg: 56–74%; juvenile: 20%). In May 2011, four 30 × 30 m plots in each of four blocks were randomly assigned to four treatments: installation of temporary dams, manual removal of 90% of trees, tree removal and dam installation, and no manipulation. The 0.5-m high dams spanned the downstream edge of their plot. From 15 May–15 June and 7 July–7 August 2012, a potted sedge Carex mitchelliana plant was placed in the centre of each plot. Each plant had a known number of butterfly eggs, laid by caged wild-caught females prior to placement. The number of eggs on each plant which survived after 48 hours was counted. In addition, in each of three arenas/plot (created from polyethylene food drums), centred on mature sedge, five captive-reared caterpillars (first to third instar) were released and the number of emerging adults was counted.

    Study and other actions tested
Please cite as:

Bladon A.J., Bladon, E. K., Smith R.K. & Sutherland W.J. (2023) Butterfly and Moth Conservation: Global Evidence for the Effects of Interventions for butterflies and moths. Conservation Evidence Series Synopsis. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

Butterfly and Moth Conservation

This Action forms part of the Action Synopsis:

Butterfly and Moth Conservation
Butterfly and Moth Conservation

Butterfly and Moth Conservation - Published 2023

Butterfly and Moth Synopsis

What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust