HomeMy WebLinkAbout5-1 Surface Water 2019-09-24Surface Water
This section is a response to the requirements of the City of Bozeman Unified Development
Ordinance Section 38.220.060 relative to Surface Water.
A map of the Existing Surface Water Features sketched in 2005 is provided in this section.
However, since 2006, Phase 4 of the Bozeman Gateway has been significantly disturbed due to
surrounding commercial development. An unnamed drainage along the eastern side of the
property once drained into the Farmer’s Canal which has since been rerouted and piped
underground along the south boundary of the project. With the rerouting of the Farmer’s Canal,
a steady source of water was no longer provided to the unnamed drainage and wetland feature.
Therefore, the unnamed drainage has become a drainage swale which now only receives
occasional stormwater runoff from surrounding parking areas and streets.
Two culvert/bridge crossings will be installed with the project providing access across the
unnamed drainage to parking facilities. The Bozeman Gateway Drainage Plan calls for 30”
concrete culverts or an equivalent capacity bridge span to be installed at the crossings.
Wetlands and Permits
Wetlands on the site have been studied extensively. A wetland delineation was completed for
Phase 4 of the property in September 2019. The primary mitigation is to avoid and preserve the
wetland characteristics where possible. Based on the results of the wetland delineation
performed according to USACE guidelines, it is Morrison-Maierle’s professional judgement that
no waters of the US are located within the project area. A copy of the wetland delineation is
provided at the end of this section.