Create or restore waterways

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

Study locations

Key messages

  • Two studies evaluated the effects of creating or restoring waterways on reptile populations. Both studies were in the USA.


  • Community composition (1 study): One site comparison study in the USA found that restored and pristine streams had similar turtle community composition.


  • Abundance (2 studies): One site comparison study in the USA found that restored and pristine streams had a similar abundance of turtles. One replicated, site comparison study in the USA found that creating new waterways by redirecting flows during forest restoration had mixed effects of reptile abundance.


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 site comparison study in 2009 in 12 streams in North Carolina, USA (Dudley et al. 2015) found that restored streams had similar overall turtle abundance and community composition to pristine stream habitats. Turtle abundance was statistically similar in restored streams (9 turtles/site) compared to pristine streams (4 turtles/site). Overall, turtle communities were statistically similar between restored and pristine streams, although turtle community composition was correlated with habitat characteristics (water quality and habitat structure) that were significantly different between restored and pristine streams (see original paper for details, including abundances of the eight turtle species captured). Turtle abundance and species richness was compared in six restored and six natural, undegraded streams by trapping turtles using hoop nets in May–July 2009 (12 total trap nights/site). Restored streams were in their second to fifth growing season after restoration and shared similar characteristics (see original paper for details of restoration approach). Pristine streams were selected based on biological integrity and proximity to restored streams. Captured turtles were weighed, individually marked (or assessed for distinguishing scars) and released.

    Study and other actions tested
  2. A replicated, site comparison study in 2012–2014 in saltcedar Tamarix ramosissima-cottonwood Populus fremontii forest along a river in Utah, Arizona and Nevada, USA (Mosher  & Bateman 2016) found that the impact of redirecting water flows as part of forest restoration, along with mechanical tree removal, herbicide treatment and replanting native species, on overall lizard abundance was mixed. Trapping surveys indicated that overall lizard abundance was similar in restored stands (127–171 lizards/site/100 trap nights) compared to unrestored stands (62–74), whereas visual encounter surveys found that overall reptile abundance was greater at restored sites (results reported as statistical results). See original paper for the effects of restoration on individual species. In winter–spring 2012–2013, restoration of saltcedar-cottonwood/willow Salix spp stands was carried out along the Virgin River, including: introducing/redirecting water flows by trenching, mechanically removing 50% of saltcedar and Russian olive Elaegnus angustifolia, spraying stumps with herbicide and transplanting native plants. Saltcedar in Utah was subject to biocontrol by northern tamarisk beetles Diorhabda carinulata from 2006 (see original paper for details). Reptiles were monitored in two restored and six unrestored stands in May–July 2013–2014 using drift fences with pitfall and funnel traps (1,060 total trap days) and visual encounter surveys (3 transects/site, see original paper for details).

    Study and other actions tested
Please cite as:

Sainsbury K.A., Morgan W.H., Watson M., Rotem G., Bouskila A., Smith R.K. & Sutherland W.J. (2021) Reptile Conservation: Global Evidence for the Effects of Interventions for reptiles. Conservation Evidence Series Synopsis. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

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Reptile Conservation

This Action forms part of the Action Synopsis:

Reptile Conservation
Reptile Conservation

Reptile Conservation - Published 2021

Reptile synopsis

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