Import a SVN repository into a Git repository, complete with branches and tags. Script inspired by the method described by StackOverflow answer http://stackoverflow.com/a/3972103/123597

Git-Import-SVN.ps1

Param(
    [Parameter(Mandatory=$true, Position=1)]
    [string]$SvnFolderPath,
    [Parameter(Mandatory=$true, Position=2)]
    [string]$TargetFolder,
    [Parameter(Mandatory=$true, Position=3)]
    [string]$GitUrl
)

git svn clone --stdlayout --no-metadata -A users.txt $SvnFolderPath "$TargetFolder-tmp"

cd "$TargetFolder-tmp"
$remoteBranches = git branch -r

foreach($remoteBranch in $remoteBranches)
{
    $remoteBranch = $remoteBranch.Trim()

    if($remoteBranch.StartsWith("tags/"))
    {
        $tagName = $remoteBranch.Substring(5)

        git checkout -b "tag-$tagName" $remoteBranch
        git checkout master
        git tag $tagName "tag-$tagName"
        git branch -D "tag-$tagName"
    }
    elseif($remoteBranch -notlike "trunk")
    {
        git checkout -b $remoteBranch $remoteBranch
    }
}

cd ..
git clone "$TargetFolder-tmp" $TargetFolder
rm -Recurse -Force "$TargetFolder-tmp"
cd $TargetFolder

$remoteBranches = git branch -r
foreach($remoteBranch in $remoteBranches)
{
    $remoteBranch = $remoteBranch.Trim()

    if($remoteBranch -notcontains "HEAD" -and $remoteBranch -notcontains "master")
    {
        $branchName = $remoteBranch.Substring(7)
        git checkout -b $branchName $remoteBranch
    }
}

git checkout master
git remote rm origin

git remote add origin $GitUrl
git push --all 

This is way easier than https://john.albin.net/git/convert-subversion-to-git, which is what I was trying to follow before.

I did have to remove --stdlayout from line 10 to deal with Subversion repos that weren't setup with the standard trunk/branches/tags structure. I was otherwise getting an error about the Git repository being empty.

Thanks for the tip @JamesSkemp

I'm afraid the condition $remoteBranch -notlike "trunk" in line 28 is always false. Did you mean $remoteBranch -notlike "*trunk"?
The same issue is in line 44. $remoteBranch -notcontains "HEAD" is always false because -contains and -notcontains don't mean "string contains/not contains substring", they mean "if a collection of objects includes ('contains') a particular object". I suppose the condition in line 44 should be $remoteBranch -notlike "*HEAD" -and $remoteBranch -notlike "*master".