Improve water retention

Improve water retention

Improve water retention01. Water flow quantity improvement

General description

Water retention and runoff can be altered by different factors such as changes in land cover, soil structure and compacting, stormwater management, loss of floodplains and wetlands. Loss of water retention combined with accelerated runoff typically increases the frequency and magnitude of flood peaks and reduces the availability of water to streams during low flow (base flow) periods (Stream Habitat Restoration Guidelines, WDFW). The alternatives for improve water retention may be applied in combination with other restoration measures (e.g. restoring side channels or former meander is firstly done for restore channel morphology and lateral connectivity but also increases infiltration area) at different spatial scale and location (riparian zone, nearby land, etc). Some techniques for improve water retention are:

• Changes in land use and cover

• Improve stormwater management

• Reduce and limit the amount of impervious surfaces in the watershed

-Change land use practices and zoning regulations to limit the allowable percent of impervious surface in the watershed

-Decommission roads

-Use pervious pavement alternatives where feasible

• Minimize the extent and degree of soil compaction

• Restore stream connectivity to floodplains (see Channel Modification, Levee Removal and Modification, Dedicating Land to the Preservation, Enhancement, and Restoration of Stream Habitat techniques)

• Revegetate denuded areas within the watershed

• Protect, restore, and create wetlands and other infiltration areas

Expected effect of measure on (including literature citations):

• HYMO (general and specified per HYMO element)
• physico � chemical parameters
• Biota (general and specified per Biological quality elements)

Pressures that can be addressed by this measure

• Hydrological regime modification
• Groundwater abstractions
• Surface water abstraction

Case studies where this measure has been applied

• Renaturierung Untere Havel
• Vääräjoki - Niskakoski
• Kuivajoki - Hirvaskoski
• Spree - Restoration and remeandering of the Müggelspree - downstream Mönchwinkel
• Regge Velderberg
• Millingerwaard - Floodplain rehabilitation
• Vreugderijkerwaard - Side channel
• Narew river restoration project
• Uilenkamp - Meander reconnection
• Warta Middle River Valley
• Enns - Aich
• Buiten Ooij - Sluice operation
• Polder Ingelheim – Restoring former floodplains (INTERREG Sustainable Development of Floodplains)
• Hondsbroeksche Pleij – Restoring former floodplains (INTERREG Sustainable Development of Floodplains)
• Bemmelse Waard – Restoring former floodplains (INTERREG Sustainable Development of Floodplains)
• Rhine - Polder Altenheim
• Drava - River Widening Amlach/St. Peter
• Drava - River Widening Obergottesfeld
• Drava - River Widening Rosenheim
• Rhine - Nebenrinne Bislich-Vahnum (LIFE08 NAT/D/000007)
• Meuse - Overdiepse Polder
• Rhine - Ontpoldering Noordwaard