北勢溪河段現設有防砂壩7座（台北水源特定區管理局轄內），大多於10年前完工，且多設有魚道，惟受上游砂石堆積影響，部分魚道已被土石掩蓋，無法發揮功能。爲改善北勢溪之河川棲地環境，進行河川生態調查，並針對現有魚道之功能就生物性、水理性及結構性進行檢測與評估。由北勢溪7座防砂壩附設魚道調查結果發現：除坪林5號防砂壩魚道主體結構有受損外，其餘6座魚道主體結構尚爲完整；上德4號魚道因完全爲砂石阻塞，已無魚道功能；上德1號、2號、碧湖1號與粗窟1號魚道隔板設計之開口均爲同側，影響阻流效果，造成魚道內幾無休息區；上德1號、坪林1號及坪林5號魚道阻流隔板受損；上德2號及上德1號魚道出入口有阻塞或障礙，生物廊道功能不佳。由坪林1號、坪林5號、上德1號及粗窟1號4座魚道之上溯試驗中皆有發現上溯魚；其中以坪林5號魚道發現之上溯魚最多，此結果足以顯現魚道施設於防砂壩之重要性。

There exist seven check dams at Pei-Shih Creek governed by Taipei Water Management Office. Most of them were completed decade ago and built with fishways. Some fishways are lost of functions and covered by sediment deposition because of sediment transport from upstream. Stream ecological investigation has been implemented to improve the river habitat of Pei-Shih Creek. Meanwhile, the biological, hydraulic, and structural investigation and assessment for these fishways were done for selecting suitable case to carry out preliminary enhancement engineering planning. From the investigation results of existing seven check dam ancillary fishways, only Pinlin No. 5 check dam fishway main structure damaged, the other six fishways main structure remain undamaged. Sunte No. 4fishway lost its fish migration function for sediment deposited completely. The baffle notches are built at the same side for Sunte No. 1, No. 2, Peehu No. 1 and Chuku No.1 fishways. This design may decrease the flow retarding effects and reduce rest areas inner fishways. Part of Sunte No. 1, Pinlin No. 1 and Pinlin No.5 fishway baffles are damaged. The entrances of Sunte No. 2 and No.1 are blocked or obstructed so that the biological passage functions are limited.